How would you like it if I told you there was a way to eat pretty much anything and everything you wanted to eat and still maintain your health? Or better yet, what if I told you that you could eat pretty much anything and everything you wanted and even improve your health? Would you be interested?

I figured as much.

There is a way to reduce blood sugar, improve insulin sensitivity, reduce blood pressure, increase HDL levels, get rid of diabetes, live a lot longer, and still be able to lose a little weight. All without giving up the foods you love. And without having to eat those foods in tiny amounts.

Sounds like a late-night infomercial gimmick, but it isn’t.

Before I get to the real nitty gritty of how such a thing can be done, let’s look at a method that has been proven in countless research institutions to bring about all the above-mentioned good things. It’s called caloric restriction.

When researchers restrict the caloric intake of a group of lab animals to about 30 to 40 percent of that of their ad libitum (all they want to eat) fed counterparts, they find that the calorically restricted animals live 30 percent or so longer, don’t develop cancers, diabetes, heart disease, or obesity. These calorically restricted (CR) animals have low blood sugar levels, low insulin levels, good insulin sensitivity, low blood pressure and are, in general, much healthier than the ad lib fed animals.

Most of the work in caloric restriction has been done on rodents, but there is a long term study on Rhesus monkeys (17 years at this point) that appears to confirm the rodent data on longevity and health with CR in primates. There are no human longevity studies, but there are a number of human studies on CR and health that show that human subjects under CR conditions reduce blood sugar, improve insulin sensitivity, reduce blood pressure, etc., so it stands to reason that if humans reduced their caloric intake by 30-40 percent for their entire lives, they would also live longer.

Caloric restriction is a terrific way to lose weight and get healthy; problem is, it’s not much fun.

When rats live out their little ratty lives calorically restricted in their cages they seem to show signs of depression and irritability. Primates do for sure. If primates don’t get enough cholesterol, they can actually become violent. But, if you’re willing to put up with a little irritability, hostility and depression, it might be worth cutting your calories by 30 percent for the rest of your long, healthy miserable life.

Doesn’t sound so cheery? You’re not ready to sign up yet?

Well, there is a better way.

A number of different research teams have studied a method by which rodents can get all the health and longevity benefits of caloric restriction without calorically restricting. And the method has been studied in humans and seems to achieve the same health benefits and, if an old Spanish study can be believed, maybe even an increase in lifespan.

What is this magic method?

Intermittent fasting.

In regular fasting one goes entirely without food, which is caloric restriction carried to the extreme. Going entirely without food in the short term leads to improvement in health, but also leads to an extremely short life unless the fast is aborted.

Intermittent fasting (IF) is just as its name implies: a period of fasting alternated with a period of eating.

But isn’t that what we do anyway? We eat breakfast, then fast until lunch. Then, after lunch, we fast until supper. Then we fast all night. Uh, not exactly.

In research settings animals that are intermittently fasted are fed every other day, so they eat whatever they want for a day, then they are denied food for a day. Interestingly, on feeding days most of the animals eat a almost double the amount that their ad lib fed mates do. Thus the IF animals eat about the same number of calories overall that the ad lib fed animals eat, but, and this is a huge ‘but,’ the IF animals enjoy all the health advantages that the CR animals do, and, in fact, are even healthier than the CR animals.

Like caloric restriction, intermittent fasting reduces oxidative stress, makes the animals more resistant to acute stress in general, reduces blood pressure, reduces blood sugar, improves insulin sensitivity, reduces the incidence of cancer, diabetes, and heart disease, and improves cognitive ability. But IF does even more. Animals that are intermittently fasted greatly increase the amount of brain-derived neurotrophic factor (BDNF) relative to CR animals. CR animals don’t produce much more BDNF than do ad libitum fed animals.

What’s BDNF? (The Wikipedia definition is actually pretty good)

BDNF, as its name implies, is a substance that increases the growth of new nerve cells in the brain, but it does much more than that. BDNF is neuroprotective against stress and toxic insults to the brain and is somehow–no one yet knows how, exactly–involved in the insulin sensitivity/glucose regulating mechanism. Infusing BDNF into animals increases their insulin sensitivity and makes them lose weight. Humans with greater levels of BDNF have lower levels of depression. BDNF given to depressed humans reduces their depression. And Increased levels of BDNF improves cognitive ability. In short, you want as much BDNF as you can get., and withIF you can get a lot.

But, who wants to go all day every other day without food?

Well, you don’t have to. MD and I, using ourselves (selflessly, I might add) as subjects have worked it out.

Most rodents feed throughout the day and night, so restricting them for 24 hours does just that: it restricts them for 24 hours. In humans, however, the situation is different. We humans, for the most part, eat only during our waking hours. So if we fast for a day, we end up fasting for about 34 hours and eating for 14, which isn’t the same as 24 on, 24 off.

Let me show you what I mean.

Let’s say you pick a day to start. You eat all day, then go to bed, wake up in the morning and fast all day, then go to bed. You wake up the next morning and eat all day, then go to bed and start again. So, assuming you eat until 10 PM on your eat day, once you quit eating you don’t eat again until 8 AM 34 hours later. If you eat from 8 AM that day until 10 PM, you’ve eaten for 14 hours. so, you’re on (eating) for 14 hours and off (fasting) for 34. MD and I spent a couple of weeks doing it that way, and I’m here to tell you, it’s no fun. At least not on the fast days. The eating days were a different story; they were great, but we would spend the entire day dreading the fast day coming up.

We fooled around with a number of different eat-fast-eat regimens and came up with something that works pretty well. We set up our cutoff time as 6 PM. On the day we started, we ate until 6 PM, then fasted until 6 PM the next day. On the next day we ate supper right after 6 PM and ate breakfast and lunch (and a few snacks) the next day until 6 PM when we started fasting again.
The advantage of this regimen is that we were able to eat every day. One day we would get supper–the next day we would get breakfast and lunch. On no days would we go entirely without food. This schedule worked the best for us.

On the times during the day that we ate, we didn’t stick with our normal low-carb fare; we ate pretty much whatever we wanted, including a fare amount of higher carb stuff. We stuck with the regimen for a few weeks just to see if we could tolerated it, which we did just fine. We ultimately drifted back to our normal low-carb diet, however, just because it seemed to work better with our schedules. We could have been happy on the intermittent fasting regimen for the long term.

I would think that the optimal way to go would be to follow an intermittent fast using low-carb foods during the eating periods. One would get the best of all worlds healthwise this way.

Over the period that we followed the various IF regimens we lost a little weight because, unlike the rodents, we couldn’t eat twice as much during the eating days as we would have eaten were we not fasting. We didn’t check any lab work to see if any values had changed. We weren’t doing a hard core study; we were simply evaluating IF as a practical means for humans to use to improve their health.

In thinking about the process I came to the conclusion that IF was probably the way Paleolithic man ate. We modern humans have become acculturated to the three square meals per day regimen. Animals in the wild, particularly carnivorous animals, don’t eat thrice per day; they eat when they make a kill. I would imagine that Paleolithic man did the same. If I had to make an intelligent guess, I would say that Paleolithic man probably ate once per day or maybe even twice every three days. In data gathered from humans still living in non-Westernized cultures in the last century, it appears that they would gorge after a kill and sleep and lay around doing not much of anything for the next day or so. When these folks got hungry, they went out and hunted and started the cycle again.

If you buy into the idea that the Paleolithic diet is the optimal diet for us today because it is the diet we were molded by the forces of natural selection to perform best on, then you should probably also buy into the idea that a meal timing schedule more like that of Paleolithic mean would provide benefit as well.

One of the things MD and I took away from our IF experience is the idea that we don’t have to eat three meals per day. We now often skip lunch and don’t seem any the worse for it.

Sometimes we get up and get going with all our projects and don’t eat breakfast. We try to skip a meal here and there because figure it’s probably good for us. When you get used to it, you don’t really even think about it. And it’s good for you. Don’t take my word for it–look at the medical literature.

There have been a few human studies on IF, and all have shown a marked improvement in virtually every parameter tested. None of the subjects in any of these studies has done the full 24 on-24 off that MD and I did. Most fasted until 5 or 6 PM on the fast days, then ate, then ate regularly on the eat days. Even with this wimpy IF schedule the subjects did better.

One of the recent papers published on the less rigid IF schedules caught my eye because one of the authors was Don Laub, who used to be the chairman of the plastic surgery department at Stanford. When I was in medical school I thought I wanted to be a plastic surgeon so I went to Stanford during a part of my senior year and worked with Dr. Laub as my mentor.

In this study, published in the journal Medical Hypothesis in March of this year, Dr. Laub along with two other physicians (neither of whom I know) underwent their version of and intermittent fast. The three of them have since May 2003 been on a version of the IF in which they consume about 20-50 percent of their estimated daily energy requirements on the fast day and eat whatever they want on the non-fast days.

Since starting their regimen they have

observed health benefits starting in as little as two weeks, in insulin resistance, asthma, seasonal allergies, infectious diseases of viral, bacterial and fungal origin (viral URI, recurrent bacterial tonsillitis, chronic sinusitis, periodontal disease), autoimmune disorder (rheumatoid arthritis), osteoarthritis, symptoms due to CNS inflammatory lesions (Tourette’s, Meniere’s) cardiac arrhythmias (PVCs, atrial fibrillation), menopause related hot flashes.

In their paper these researchers discuss a 1957 paper from the Spanish medical literature.

…the subjects were eating, on alternate days, either 900 calories or 2300 calories, averaging 1600, and that body weight was maintained. Thus they consumed either 56% or 144% of daily caloric requirement. The subjects were in a residence for old people, and all were in perfect health and over 65. Over three years, there were 6 deaths among 60 study subjects and 13 deaths among 60 ad lib-fed controls, non-significant difference. Study subjects were in hospital 123 days, controls 219, highly significant difference. We believe widespread use of this pattern of eating could impact influenza epidemics and other communicable diseases by improving resistance to infection. In addition to the health effects, this pattern of eating has proven to be a good method of weight control, and we are continuing to study the process in conjunction with the NIH.

There is much more to the IF story that I will continue in another post. I would do it in this one, but I (actually my web guy) upgraded my blogging software and somehow the little buttons that let me link to other sites are AWOL. I can’t italicize or set off quotes or do any of the things I normally do in the course of posting. I’m hoping that I will get this straightened out soon. When I do, I’ll go into the subject in a little more detail and show a chart that demonstrates the difference between CR and IF. (Note: the problem is solved; all links are working.)

In the meantime, if any of the readers of this blog would like to undertake an intermittent fast, I would love to hear the results of the experience. Please send a comment.


  1. That’s very interesting. Just yesterday it got to be close to 9:30 AM and I realized I had forgotten to eat breakfast (usually have it around 7). I went ahead and had some because I had a quiz coming up at 11 in a class I’m taking and was worried if I didn’t eat I wouldn’t be able to concentrate. We are so strongly programmed to eat 3 times a day. But in the last few weeks there have been half a dozen or more times when I thought “do I really have to eat?” or have nearly forgotten it’s time for a meal. I’ll think about giving IF a try. –Anne
    Hi Anne–
    I’ve often noticed the same thing: I’m not particularly hungry yet I eat just because it’s time to eat. If I had to go out and run some game to earth, would I be hungry enough to do so? I doubt it.
    Good luck on your IF. Keep me posted.

  2. OK Mike – I didn’t expect to read this one this morning. So a couple of questions spring to mind…
    1. How might IF affect muscle mass? If you are not getting your BCAAs from your food your body will cannibalize itself for the stuff. How long CAN a person refrain from protein and not sacrifice what you have? Any data on this? I feel if I undertook an IF regimen I’d lose lean tissue. I certainly don’t think an IF diet is conducive to anabolism but hey…
    2. Are not these IF studies done on unhealthy, overfat subjects? I can easily see why IF would help overfat and out of shape Mary Smith or Junk food gorging Joe Anderson, but taking me for example, someone with near perfect internal health markers and bodyfat composition for a 45 year young male, could IF be detrimental?
    Thanks Mike! And BTW my blog address is
    Hi Fred–
    I don’t think IF would affect muscle mass much at all. If you go without food for a long period of time, say, several days, your metabolic system goes after your muscle mass to convert the protein stored there into the glucose you need to keep your blood glucose normal. This doesn’t happen in the short term. All the protein structures in the body draw from and add to the amino acid pool. When muscle breaks down the individual amino acids go into the pool from where they’re harvested by the system that converts them to glucose. When new muscle is made, the amino acids used to construct the muscle protein are drawn from the amino acid pool. One of the contributors to the AA pool is enzymes that are no longer needed and junk proteins that the body is cleansing from the cells. When one is fasting, one of the group of enzymes not really needed is the group of digestive enzymes that would otherwise be employed in digesting food. These enzymes break down and their amino acids enter the AA pool where the muscle can pick them up as needed. Also, during an IF, the body goes into ketosis. I posted a few months back on how ketosis stimulates the process of cellular cleansing by removing junk proteins from the cells. The amino acids from these proteins also enter the AA pool where they can be recycled by the muscle mass. So, even though new protein isn’t coming into the body minute by minute from the diet, there is plenty of substrate there in the AA pool to last until the next meal, which is, at most, only 24 hours away.
    Second, although many of these studies were done using unhealthy subjects, a number were performed on people, both healthy and unhealthy, who were fasting for religious reasons. In all cases all healthy parameters evaluated improved.

    1. IF will not effect muscle mass. It takes about 3 days before your body will eat its on muscle for energy. You may appear a bit flatter which will make you believe you are losing muscle during IF this is water loss and will be replenished on feed days giving you a pumped and vascular look if you are already lean the results will be even greater.

      1. Check out Dr. Shelton’s Hygenic Fasting, very informative…My longest fast year to date is 32 days, with absolutely no ill effects…

      2. You know, I was thinking that even after a few days that the body would probably go after the same muscle cells that have areas of dysfunction just like it would do in any other cell during a one day fast. In other words I can’t see how or why the body would go after healthy muscle cells first or any healthy cells first for that matter. New muscle cells I’m assuming would be made during the regular eating days that genetically you are supposed to have and therefore would make up for the ones or the parts of ones it ate. It seems that’s what one day fasts that include autophagy would do especially concerning the auto immune processes. You get new white blood cells etc. I’m certain that short and intense full body resistance exercises would ensure that new muscle cells or cell parts would be manufactured. Just speculating

  3. I can attest, Mike, it does work, exactly as you said. I don’t do the day on, day off — I found that a bit too disruptive. For close to a year, I’ve eaten just once a day, usually something like a meal and a half between 6-8 pm, fully low-carb, and eating nothing the rest of the time. Benefits are as you mentioned — nuisance health issues go away, zero colds/flu, weight dropped to a comfortable lean zone, and oddly, energy actually INCREASES during the non-eating time. Sure, I get stomach-grumbling hungry late in the day, but it’s easy to take, since I know I’ll be eating later. (Oddly, the feeling isn’t all that unpleasant after a while — somehow makes you feel more alive and tuned.)
    I notice coming up on dinner time, I actually get a surge of energy and almost fidgetiness, which I sometimes need to burn off with some exercise. (Which is, I suppose, how Paleo man had the energy to make a kill, even when he hadn’t eaten in a while.)
    I know Loren Cordain seemed to be intrigued by the idea of once-a-day meal frequency, as he covered in one of his recent newsletters.
    There’s clearly some value to going long(er) periods without food — some sort of metabolic grooving or run-out that the body seems to love. Grazing never worked like that for me.
    There’s also a huge psychological benefit here, too: Every day has a great ending. Something you can look forward to.
    After the day’s labors, you get to sit down to a ‘feast’ of sorts, and loll about in delicious laziness afterword, guilt-free. There’s a more natural biological rhythm to that, at least for me.
    Also, you get to experience the exquisite pleasure of eating well, when you’re truly deep-down hollow hungry. Which we hardly ever experience any more.
    Hi Walt–
    You’re right on all counts. The hunger is exquisite and the food much more tasty and fulfilling after waiting for it for a while and really looking forward to it. Most of us don’t experience real hunger anymore; we just think we do.
    The French don’t like to snack between meals because they feel that the snack diminishes their hunger and prevents them from fully experiencing the meal. I think they’re right.
    Loren Cordain and I have had many, many conversations about meal timing. I got him started on the idea a couple of years back. He, too, believes it is the Paleolithic way and that meal timing could be equal in importance to meal composition.

    1. Is it me, or is about everyone in the Paleo movement ripping Ori Hofmekler/Warrior Diet off…
      I gotta say Mike your post was almost verbatim Warriior Diet.. heck, the whole IF upstart of recent is on the heels of Ori/Warrior Diet, which has been out for 6+ years…
      I wouldn’t have no much problem with it, esp. among professionals like you who seem to be coasting on a bit of sucess from others, would give Hofmekler his due credit when these discussions/debates/postings come up… man this makes me agitated since I am seeing it everywhere…

      1. I don’t see how this looks like the Warrior Diet. Someone above posted they were doing what looks like the Warrior Diet. Don’t eat all day and have just one big meal. Mike was alternating days not eating. One day on, one day off.
        Explain how they are the same “verbatim”.

    2. WAltk,
      What you did is called restricted feeding, and has a slightly different mechanism… you were “lucky” because as long as I understand, Restricted Feeding only works like IF when the eating is doing almost in the night time, because cheats the circadian rhythm of your body and “reset” the cycle, so it could be adjusted to the feeding pattern, without de-synchronize the clock of your organs and tissues and the clock of hypothalamus.
      I might add, that the IF system that Mike made up, might be a combination of both…

  4. Very interesting stuff indeed. I have to talk this through with my husband, but I am positive I’ll give this a try over the next weeks, and will keep you informed.
    Hi Detox–
    I’ll await your response. I’m keenly interested.

  5. Oh, and on CR:
    Mike, I always wondered about energy expenditure among the CRers. If you’re only eating, say 1600 calories per day, you can only be burning 1600 (if you’re weight-stable).
    Which means, you can’t be very physically active; no one-on-one basketball in the driveway, no running. Not too many workouts with weights.
    I’m guessing CR’d animals and humans tend to get a bit quiet and sedate — and miss the benefits of vigorous exercise. Unless of course, CR makes up for it in some way.
    (Didn’t mean to monopolize.)
    No problem. I don’t remember if any of the CR studies discuss the activity levels of the animals. I’ll go back and check. I wouldn’t bet my life on it, but it seems like the CR ones were actually a little more active.

  6. This article sounds much like something Art Devany would recommend. He is writing a book called Evolutionary Fitness, training and eating like a human did hundreds of years ago. Fasting is part of the regime. He has a website, Your take on food is very similar to his.
    My wife and I embarked on a fasting program just a few weeks ago, going without food for a good part of the day, and then eating dinner. We do use juice (have a juicer), maybe a glass or two of a vegetable or fruit juice, with lots of water, no coffee. So far we find that we feel a bit ill while we detox, but feel better overall after a day or two. One other note, eating only when hungry is the way to go. How many people are “programmed” to eat at work breaks or social events (where the food is usually bad) because that’s what you do? If you are not hungry, don’t eat!
    Hi Audley–
    Well said. If you’re not hungry, don’t eat. Seems pretty simple, but it’s amazing how many people eat at set times whether hungry or not.
    Keep me posted on your IF efforts.

  7. There is a diet that uses IF: The Warrior Diet. Its not alternate day fasting however. One basically confines all their eating to a 4 hour window, so you’re fasting 20 hours/day or so.
    The author is not a fan of low carb per se, but is a big advocate of whole foods, etc.
    Hi VikingDan–
    Some time in my dim and distant past I think I read The Warrior Diet. Wasn’t it written by an Israeli commando guy? If I remember correctly, he did bad mouth low carb, but recommended eating a big meal once per day as he believed the warriors of times past had done.
    The nice thing about IF is that one can get the benefits from it without sticking to a strict low-carb diet, although I suspect it works even better with a low-carb diet.

  8. This sounds really interesting, and I think I might give it a try.
    What was your experience with exercise while you did your experiment, and with your current intermittent meal skipping? I would guess it would still be workable, depending on how you schedule your workouts.
    Hi Cathy–
    I didn’t change my workout schedule at all. It didn’t seem to make a big difference when I worked out relative to when I was fasting.
    The scheduling problem we did have was with social engagements. If we were invited to a dinner somewhere that was set for an evening when we were supposed to be fasting, we simply moved our time to start fasting until after the dinner. For example, if we were supposed to start fasting at 6 PM as per our regular schedule but instead had a dinner engagement that evening fat 7:30 PM, we ate the dinner, started fasting at 8:30 (or whenever the dinner was over) and fasted until 8:30 the next evening. Then we ate from 8:30 PM until 6 PM the next evening and got back on schedule.

  9. Wow. This post sounds great. I haven’t read the whole thing but definitely will. I am aware of some of the research on calorie restriction diets and I think it’s all quite fascinating. I would include exercise as another way to induce a sort of caloric restriction as well.
    Anyway, you mentioned you did not know of Art Devany. When you have an hour or two you might want to read this:
    From what I can tell, most if not all should be right up your alley. Art can be a bit much at times, but his ideas are great. Your blog and his are two of my favorites.
    I also like these sites if you are interested:
    I might post again after I read the rest of this latest post.
    Thanks for the great info,
    Daniel Chong
    Hi Daniel–
    Thanks for all the links. Let me know if you give IF a try.

  10. don’t you get unbearably hungry during the fasting periods? I couldn’t imagine getting thru a day at work without any breakfast or lunch, and I have a fairly low stress job.
    anyway, if I did try this, I imagine I would try it with a low carb diet, why not have the best of both worlds?
    Hi mrfreddy–
    Surprisingly, you don’t really get all that hungry during the day. And it’s nice to know that a big, fat juicy meal is awaiting you at 6 PM. I’m here to tell you that the 6 PM meal is one you will really enjoy.

    1. Yep, you’ll be really hungry the first time you try IF. However, each time you do it you will feel hunger later in your fast and less intensely.
      I have done several 36-hour fasts this year. I’m not a true IFer, but I try to do a 36 hour fast once a week (sometimes twice). I have found that each one is a little easier than the previous one.
      Now my desire for food when I fast is more taste-based. It is kind of ikelike wanting some desert after having a meal. “I’m not really hungry, but I REALLY want some mango. ”
      I don’t believe that this is because I’ve built up more will power. (Maybe that accounts for a little bit of the lack of hunger.)
      My paradigm is that even the thinnest of us have a lot of fat and other tissue that can be converted into energy. However, the enzymes and other resources necessary to convert those potential energy sources need to be built up or we will experience hunger long before those reserves are used up.
      When you fast regularly, you build up your ability to convert fats into energy (and in so doing get rid of the toxins that are stored with the fats, you also generate growth hormone, resveratrol and BDNF).
      It is sort of like what would happen if we decided to move away from gasoline to some other fuel. Even if that fuel was abundant, we would still experience “hunger” until we built enough refineries that could convert that new fuel into a usable form.

  11. I could just weep. I would often do this naturally as a child–or I should say, I would try, and then get disciplined by my parents.
    I think that many parents, working with the bad cultural info that’s available, often completely screw up their children’s instincts. Of course, it’s done out of concern and love, which makes it so sad.
    If you have read anything on the history of childrearing customs throughout the past few centuries in Western cultures, you know it’s been pretty appalling anyway.
    When I look back on what was required of me and many of my childhood friends I can understand why so many of us have ended up obese.
    I think I will try the IF starting today. I’ve had my rare steak for breakfast, so I will eat till 6 pm tonight, and then start after 6 pm tomorrow.
    A few questions — do coffee and tea count as food, or must it be strictly water–could club soda be used on the fast? Does this change at all how any exercise is scheduled? What about supplements on the morning of the fast? I’m assuming that very low carb can still be used on eating days, I can just have more of whatever it is I’m eating.
    Hi LCforevah–
    I’m in total agreement with you about the child rearing issues. How many of us have been told that we couldn’t do this or that or couldn’t leave the table until we cleaned up our plate, that children in China were starving, etc. Kids, before this kind of programming, eat when they’re hungry. It is kind of sad that the adults in their lives try to break them of their natural instinct.
    As to your questions…
    No, coffee, tea, diet drinks, etc. don’t count. At least they didn’t for us. I would drink away.
    We didn’t change our exercise schedules, so I don’t really have a recommendation there. It didn’t seem to matter to us.
    We did take our supplements on fasting days, we just took them during the period during the day when we were eating, i.e., before 6 PM or after 6 PM depending on the day.
    You can indeed follow low-carb during the eating periods and eat all you want. The dinner meal at 6 PM is wonderful.
    Best of luck on the IF regimen. Keep me posted; I’m really interested to hear how it works for you.

  12. My day never feels quite complete without a Eades Blog update, so today is starting very well.
    This is very fascinating. I’ve been reading quite a lot about CR since there is an avid, practicing CRON person posting on the low carb forum I frequent. One of his fellow CRONies has had good luck controling Lupus with the diet.
    Also, amongst ankylosing spondylitis patients I talk to (me being one) they sometimes use fasts to get out of a flare. Many also seem to have some luck with a No-Starch Diet. I’ll have to post a link to your article on message forum and perhaps the IF might be something that could help.
    Considering the enormous amount of Pad Thai I had last night… I should IF today.
    Hi Nancy–
    Thanks for the nice words about the blog; I really appreciate it. I’ll try to be more diligent in my posting, so that more of your days will be complete.
    There exists a fair amount of data that low-starch diets (and low-carb diets) work to prevent flare ups of all kinds of autoimmune disorders. Fasting itself gives the GI tract time to heal. It helps the healing process, whether fasting or not, to take 4-10 grams of l-glutamine per day.
    If you do decide to give IF a try, be sure to let me know how it works for you.

  13. You might already know that twice-a-week IF is the norm for (traditional) Orthodox Christians. The Wed & Fri fasts start after dinner on Tue or Thu – and no meals are eaten until after 3 pm on Wed & Fri – and those are one or two small, vegan-no-oil meals. And of course, nothing by mouth after dinner on Saturday until after Liturgy on Sunday – usually around noon.
    this is year-round – there are of course other times when the vegan-no-oil diet is followed for up to 40 days at a time (Great Lent, Nativity Fast, etc).
    Hi Lisa–
    Many religions have incorporated fasting for various lengths into their customs. A number of scientific articles have been generated from data collected from religious groups undertaking these fasts. In all cases (at least all the studies I’ve read) most health parameters improved during the fasting period.

  14. I’m very interested — excited, even — about this! This is the way I used to eat back when I was a student. (Way too many years ago.) It was the way I felt best and had the best energy to meet all the demands of working full time, going to school, hiking all over campus, etc. I had discovered it was the best way to avoid hypoglycemia problems — no problem at all if I just ate once a day, at dinner. It was also very convenient. It’s amazing how much time and effort goes into planning our next feed! Much easier if it’s just once a day.
    Eventually over the years I have succumbed to all advice that not eating several times a day could cause weight gain (starvation mode, etc.). Even though that really doesn’t make sense if you think it’s at all wise to try to eat like our ancestors.
    Yesterday I exercised after not having eaten for quite a while — and felt much stronger than usual.
    Hmmmmm…. I think I’ll try my old eating schedule. Do you think black coffee would mess up the fasting times?
    Hi PeggyJo–
    No, black coffee won’t mess it up. Go for it. I had black coffee throughout the entire time I was fasting. Same holds for tea or any other non-caloric beverage.
    Keep me posted.

  15. It sounds like some of us are really interested in implementing various versions of this and tracking our results. Any way for you to do some kind of informal data collection here?
    Hi PeggyJo–
    I think it would be great to do that. Let me think about how we could bring it about. I’m going to be talking to my web guy later today; I’ll ask him for some suggestions.

  16. hmmmm, this sounds very familiar to how the Hellers started their Carbohydrate Addict saga.
    I believe it was Mrs Heller that would fast until evening and then allow herself to eat a reward meal in the evening. She lost significant fat and thus the Carb Addict revolution began….so IF in another incarnation, eat once in 24 hrs….it worked for me 18 years ago, i wonder why i stopped. Probably because someone told me it was unhealthy…I’m going to try it again.
    Hi Deb–
    Actually followers of the Carbohydrate Addicts Diet ate very low carb throughout the day, then had a ‘reward meal’ at night, which was, basically, as much food as they could cram in their mouths over a one hour period. Since these folks were eating all day, they weren’t really on an IF.

    1. I do remember Mrs. Heller writing her story about how the diet came about just as the above poster mentioned. She had some medical tests that required fasting, and did not eat all day then ate a huge meal at night. She lost 2 pounds so did the same thing the next…and the next. She lost 150 pounds. SHE was fasting….but the diet does not require you to.
      Loved the article anyway…just had to add my 2 cents!

  17. Another great blog entry Michael. Thanks..
    Like some others mentioned, I used to eat like this all the time. However, back then I would eat only once or twice every day and overeat on carbs. Lowering carbs would have made a world of difference.
    I had pretty decent results with a PSMF-like approach and eating only 1000 kcals one day and overeating another day. However, my workouts would always be scheduled on the overeating days.
    Back then I hadn’t thought of IF-regimen and tried to stick to 4-5 meals/day in the bb-fashion. This method would be tons easier.
    The method seemed a bit confusing at first. To summarize :
    day 1 : eat bf & lunch = eat before 6 pm
    day 2: eat dinner = start eating after 6 pm
    day 3: eat bf & lunch = eat before 6 pm
    day 4: like day 2… rinse & repeat.
    basically dinner-lunch-bf / – – – /
    Hi Yvana–
    You’ve got the scheduling correct. I should have put it that way in the post–it’s much easier to understand.

  18. I’m trying to integrate this into my thinking and have a few questions.
    I’ve been reading Dr. Berstein’s “Diabetes Solution” book and he talks about how overeating, even no carb food, can cause the body to release excess insulin and glucagon, due to the upper small intestine getting stretched. This makes sense from a paleo POV, since you would want to put on some fat every time you ate, even if you were gorging on mastadon meat.
    It seems like gorging one day and then fasting the next would play havoc with BG over time in a modern world, where we can’t loll about after gorging ourselves. Could you not get a similar effect by eating small amounts ONLY when physically hungry?
    I’ve lost weight in the past (and am losing some more now) this way. I eat enough to not be hungry and make sure I don’t stretch my stomach. If I’m only hungry once during the day, I only eat once. If I’m working hard, I may be hungry 4-5 times a day.
    It seems like that would give you similar results without the insulin response. My blood pressure has gone down a lot since I started eating this way and my fasting BG has gone down (I’m not diabetic; I just monitor it). My BG has been very stable too.
    What do you think?
    BTW, food tastes MUCH better when you are physically hungry. You can even tell when you start to cross over into overeating, because the food starts to change flavor. You, of course, have to pay attention and not read or watch TV while eating.
    Thanks for the great blog!
    Hi Ryan–
    The ‘stretch’ reflex could conceivably cause a problem, but in all the studies I’ve read, glucose levels and insulin sensitivity improve. Apparently something corrective happens during the 24 hours in which one isn’t eating.
    If you are a type II diabetic I would be most interested in learning how an If regimen works for you.

  19. OK, the health benefits seem to be a given. My practical mind jumps to other, non-health related pluses. This would have to have a positive impact on the grocery bill as I doubt you would eat twice as much on non fasting days. If you aren’t restricting carbs as much, you could also eat more of cheaper higher carb veggies and whole grains. I love the idea of only having to do food prep and kitchen clean up every 2nd day. Think of what other worthwhile activities could take up that time!
    Back to the health issues, after 3 years low carb, DH has much improved his health parameters, but would really like to get the weight and blood pressure down just a little more. Maybe this will do the trick, if I can convince him to give it a try.
    Hi Sue–
    I hadn’t considered the other virtues of every other day eating such as only having to clean the kitchen half as much.
    If you can get DH to give it a go, make sure and let me know how it works.

  20. Yes, I also remember that from the first edition or printing of the Carbohydrate Addicts book. It was not the diet they outlined as the program, but the way that Rachel Heller had initially discovered worked for her weight loss — eat just in the evening without paying too much attention to *what* was eaten.
    I’m also doing a lot of thinking right now about why I stopped trusting my instincts and eating when, what, and how worked for me. Hmmmph!

  21. Sounds absolutely fascinating! I lost 140 lbs low carb but it took me so long to do it, Mar 03 to Oct 05 and in the past year I gained about 12 lbs. definitely will give this a try and started today. So, I eat until 6 p.m. Then don’t eat again until Fri at 6 pm, One meal.Then eat all day, or until 6pm Sat and then not again until 6 pm and so on. Does that about cover it? I think I will stay pretty low carb, i feel better. Thanks again for a wonderful blog. I check every day to see what is new in Eadesville!
    Hi Tess–
    I’ll try to keep the news from Eadesville a little bit more up to date.
    You’ve got the schedule down. I’ll copy the exact layout from one of your fellow commenters, Yvana, comments:
    day 1 : eat bf & lunch = eat before 6 pm
    day 2: eat dinner = start eating after 6 pm
    day 3: eat bf & lunch = eat before 6 pm
    day 4: like day 2… rinse & repeat.
    basically dinner-bf-lunch/ – – – /
    Please let me know how it works for you.

  22. Hi Dr. Eades,
    Gotta totally agree with you on this one. I’m on a zero carb diet (only eating from the animal kingdom, no veggies, starches, sugars, low-carb products, etc.) and I often go extended periods without anything to eat, without even tying really, especially if I happen to be busy. I’ve easily gone 24 hours without eating, up to 36 hours as well and I could easily go 48hrs if need be.
    There’s only one reason to be hungry and that’s because of carbs in the diet and it’s fluctuations in your blood sugar, even minimal ones. No carbs=steady blood sugar levels=no hunger.
    Hi Rob–
    I think you’re right on the money. People who have never been on such a regimen don’t believe how unhungry they really are when they don’t eat carbs.
    Thanks for commenting.

  23. I’ve been really interested in this for quite some time. And I do believe there is a recent study done on humans over a 1 month period where they were fasted every other day, for the entire day and was shown to be beneficial healthwise though they didn’t get over the discomfort and crankiness on fasting days. At work now, see if I can pull it up later.
    What about for someone that is into bodybuilding and maintaining or building an above average amount of muscle. Some research shows that a fairly steady supply of aminos need to be ingested regularly to build and/or maintain muscle while dieting. For example the fat police study showed that casein was better than whey, since casein was slower digested than whey, keeping a steady level of blood amino acids. The casein group lost more fat and built more muscle than the whey group because of this. Another study on boxers eating 2 vs. 6 meals a day showed more muscle maintenance on 6 meals, although protein intake was abysmally low and the study had some shortcomings, such as a poor measure of body comp.
    Hi Pete–
    Take a look at the reply to the comment from Fred Hahn; it will probably answer most of your questions.

  24. Hi Dr. Eades,
    When I was younger (high school age), I naturally did a sort of IF. I would go to school without breakfast, not eat lunch, and then gorge myself silly from 3-5PM when I came home. After that I was usually too busy with homework/activities to eat again before bed, so this cycle amounted to eating once a day. I have to say that during this period I was very slim, had good energy, no teenage acne, etc. My senior year I began eating lunch during the day and immediately gained weight and developed some acne.
    I would be very interested in starting an IF regimen again, and have actually been toying with the idea for some time…I studied anthropology in college, so have been aware of IF for a few years now. The only obstacle is convincing my husband that I’m not crazy.
    Thanks for all your insightful commentary on this post and others. If I do start IF I will take notes to share.
    Hi Elizabeth–
    Tell your husband that I did it and I’m certainly not crazy:)
    Be sure to keep me posted.

  25. I’m so hard to convince sometimes and I admit that it sounds intriguing. Now, I may have missed it but what about water? Even if paleo-men didn’t have anything to eat and were ‘forced’ to fast intermittently, are we to also assume that they didn’t visit a water hole at all during their ‘no-eating’ periods? Or maybe we are also like animals that hibernate (bears come to mind), which don’t really need water since it’s produced from continuous fat oxidation.
    Just as a side note, a few years back there was a scientist that showed that he could extend the lifespan of the fruit fly up to 20 generations or so. Yeah, I know… flies aren’t men… but neither are rodents! Caloric restriction wasn’t what cause such extension of lifespan. Amazingly, at least in the case of the flies, what made them ‘not die’ was the removal of their eggs right after the females laid them. It seemed that the only purpose in the flies’ life was to procreate and preserve their kind. So, no eggs, no progeny… bad idea to die! The scientist then noticed that once they left the eggs, the flies actually died when they were expected too.
    Although seemingly unrelated, I always remember this account when reading about life extension… particularly because I still haven’t seen studies in which caloric restriction added pieces to the telomeres (the tips of the human chromosome arms… I know you know these but for those who don’t I offer this visual) or, which is after all where ‘life span’ resides (of course in the genetic sense).
    Perhaps when the diet is modified in some way, for example by going back to what has worked for us humans for millennia, doesn’t really expand anything in the true sense, but restores the rate at which we are suppose to age. It may sound just as semantics, but somehow, living longer and aging slowly it’s not the same, at least not to me.
    Hi Gabe–
    No, you didn’t miss anything about water; I didn’t mention it. When MD and I did our version of IF we drank water whenever we were thirsty and drank coffee and other non-caloric beverages as per our taste.
    I would like to see the fruit fly study you wrote about. I’ve looked at a lot of longevity studies (including a lot using fruit flies) and I’ve never seen that one. Are you sure it was 20 generations?

  26. Hi Doctor,
    I enjoy reading your posts. I especially like how you picked apart Jane Brody’s article.
    I tried IF for a few months earlier this year and I can attest to its efficacy. But I found it mentally unsustainable. I allowed myself weekends “off” but I still couldn’t maintain Mon-Fri, eating only dinner.
    I’m definitely going to give your schedule a try. I’ve also jumped on the low-carb bandwagon, at least for lunch anyway. I can’t convince my wife to let me go all the way for dinner too!
    PS I did allow myself coffee with honey and cream during my fasting days. It didn’t seem to adversely affect my weight loss, though I suspect the fat would come off a little quicker if I could stomach my coffee black.
    Hi Michael–
    I suspect that the IF regimen as we worked it out will be a lot more tolerable than the one meal per day IF that you did a while back. I would imagine that eating only once per day, everyday, would be a little tough.
    Good luck in bringing your wife around. Keep me posted.

  27. Hi Mike,
    Interesting post! But a question . . . Somewhere in Protein Power you advise against skipping meals since fasting stimulates insulin. Doesn’t that apply here as well?
    In general, the idea of doing Yom Kippur every other day is a little too post-dilettante for me. I would want more information on what are the benefits of IF beyond my current strategy of filling up my 50-60 gm/day carb allotment with nutrient dense vegetables and fruit.
    Hi Chuck–
    I would like to see the quote from Protein Power where we wrote that fasting stimulates the insulin response. If you can dig it up, send it my way. If I wrote it, I was wrong. Fasting definitely reduces insulin levels.
    As I say to anyone who asks, if you’re doing fine on whatever regimen you are currently following, why change? I think going without food from time to time-whether it’s every other day or once a week or so–is a good thing and provides health benefits.

  28. i have read a lot about this and have always wanted to try it but because i have tended toward hypoglycemia, i have hesitated.
    my question is, if i should start to feel the manic ravenous crazy state that i can sometimes fall into, is it best to break the fast and try another day or gut it out. will the hypoglycemic body eventually adapt to the fasting. it sounds like this way of eating should eventually improve such a condition.
    great article, the 6PM thing is genius, never occurred to me and makes it a lot easier. i will probably pick 8PM because i like to eat and watch my tv show. susan
    Hi Susan–
    I would probably try to gut it out until dinner on the fasting days. The hypoglycemic state should respond nicely. One of the most potent stimuli to feed is a rapid drop in blood sugar. If you’re not eating, the body makes plenty of blood sugar keeping levels from falling rapidly. So, once you get started you should do okay.
    8 PM until 8 PM is fine if that works for you. I hope the TV show you’re watching is Low Carb CookwoRx 🙂
    Let me know how you do.

  29. I am in dr eades, I have stopped having diet sodas I was hoping maybe with this plan i can have a soda and still lose weight? Anyway I shall keep you posted on my progress.
    Hi Sherry–
    Good luck. Keep me posted.

  30. I was thrilled to find this discussion and, as a Type 2, would be just as thrilled to see how IF would influence my BG readings. I’ve been reading on fasting in general and I firmly believe that the human body has a tremendous capacity to heal if it is given the chance. However, I am constantly seeing admonitions against diabetics fasting.
    I have recently made quite a few lifestyle changes in an effort to get my BG under control, including a low carb diet, stopping smoking and exercise. I think I’ll give all of these changes a chance to “settle down” and will make the IF routine my fourth challenge.
    I’ll let you know how it works out. 🙂
    Hi BlueBrooke–
    Good luck. Please do let me know how you do.

  31. Mike its timely that you wrote this article. About three months ago I had a little Brain flash after reading about calorie restriction. Can’t remember who wrote it but the suggestion was that calorie restriction itself might not be generating the health benefits but perhaps it was the fact that caloric restriction makes you hungry and the being hungry sets of beneficial processes. For the last two months I have avoided breakfast altogether (black coffee only) and eaten only a very small lunch. A few slices of cold meat and maybe a kiwi fruit.(the equivalent of plucking a few berries or nuts) In the evenings I graze constantly. I have felt more energetic, sleep better, and have more time in the morning! It occurred to met that in paleo times no one was mucking around in the morning preparing food. Hunters were up and away just at dawn to take advantage of that time of day when nocturnal feeders and day feeders were about at the same time, thus increasing the opportunity for a kill. Much the same way we modern hunters hunt game! Not rocket science really. It is logical that our ancestors ate in the evening after dark when there was little else to do other than sleep and well…..
    Hi John–
    I think you’re right on the money. I’m glad the regimen is working out for you.

  32. Here in south eastern Mass. we have a wonderful family owned breakfast restaurant called “Percy’s.” Yankee Magazine calls it “Heaven on Earth,” and I agree. As my wife and I are the only lowcarbers we keep Percy’s a special occasion place. When we do go, we eat like the above mentioned Paleolithic hunters. We fill up on pancakes, omelet, corn beef hash, and it just goes on. We usually wont eat again until the next day, maybe a bit of cheese around 10pm. The next day, however, we are out of ketosis and we are constantly hungry, so keeping it lowcarb sounds right to me.
    I can’t imagine going so long with out eating like on an IF plan. I LOVE eating lowcarb, I LOVE cooking lowcarb. I would miss eating like I would miss my wife if she was absent for 24 hours. IF might work, but I will gladly read about the results. Also, please post more often if you can. I can’t deal with the newspaper and need something to read during my breaks at work.
    Hi Dave–
    Looks like a lot of your fellow blog readers will be trying to IF. You can read about their results and live the IF life vicariously while you continue to gnosh on low-carb victuals to your heart’s content.
    I’ll try to pick up the pace on my postings. It’s not that I don’t have anything to say, I just don’t always have the time to say it right.

  33. Dr Eades, there’s a little group of us who’ve been toying with intermittent fasting for the past year or so, based on Dr Mattson’s research and ideas.
    We generally eat either 1 large meal per day (usually Paleo), or compress all our meals into a 4-6 hour window.
    Certainly works…I didn’t have any weight issues to begin with as I was already eating Paleo, but decided to start eating that way on a 6 week ICU rotation where we were severely understaffed (made life a lot easier). Despite already being lean, I became even leaner despite no longer having time for exercise, without losing any significant muscle mass.
    There’s been a lot of discussion about the topic over the past year or so on the nutrition board at One of the main contributors, Rob Wolff from crossfit norcal has written a lot about this way of eating, and could certainly provide you with feedback based on his and many others’ experience. I think he may have even worked with Cordain at some point. DeVany has also beein toying with the idea, but he emphasizes random fasts much more, which would be more in line with his ideas on the benefits of power laws in energy and metabolism patterns.
    On an unrelated but similarly interesting issue, you were asked about whether cold water dips worked via the principle of hormesis (from your “Cordain picnic” post). There is in fact some evidence that they do. I have a paper that shows increased levels of superoxide dismutase, catalase, and glutathione peroxidase in cold water swimmers compared to controls. There’s more out there, though in obscure and difficult to find papers. Let me know if you’re interested, I think I have some of the articles hidden somewhere in my laptop.
    PS: If you have any of the references about heat-shock proteins and cold-water dips, I’d love to read them.
    Hi David–
    Glad to hear you’ve been doing so well on the IF regimen; most people I’ve encountered who have followed such a regimen really get into it and have the same experience you did.
    As to the hormesis issue…hormesis is the situation in which a small dose of something (usually toxic; radiation, for example) prevents an untoward response from a larger dose. Animals given small doses of gamma radiation are later protected against larger doses of gamma radiation, i.e., they don’t develop cancers at as great a rate as those animals that weren’t given the initial small dose.
    In terms of the cold water hormesis would mean that a small dose of cold water would protect one from the damaging effects of a prolonged stay in frigid water. I don’t know if that’s the case. What a sudden blast of cold water (or any extreme temperature change) does is increase the body’s production of heat shock proteins, which act as chaperones in the development of new protein. Increasing heat shock protein levels increases the body’s ability to deal with stress.
    I would indeed be interested in seeing the articles on cold water immersion and increased endogenous anti oxidant production.

  34. I have to tell you a story. Back in College (SUNY Stony Brook, Anthropology), I worked as a baker, baking donuts for a chain donut shop. My schedule was erratic, as I’d start work at 9 pm, work until 7 am, take a nap, commute to college in the afternoon, take another nap and so on. Around midnight, I’d go snitch some portions of meat. Bacon, ham, tuna, roast Beef, whatever. I didn’t realize it at the time, but I was eating very low carb. The fasting part occurred because if I thought I’d gained some weight I wouldn’t eat at all for one or two days.
    For five years, I kept myself at 105 pounds by doing this. Looked great, felt great. The only thing I ever consumed at campus was coffee.
    The funny thing is that if I succumbed to the temptation of a freshly fried doughnut, I was a mess for the rest of the night.
    One of my favorite (off topic) stories is when an elderly couple came into the shop and asked about the “98% Fat Free” doughnuts. They had “a heart condition”. I told them that the donuts are fried in partially hydrogenated vegetable oil, and at the time (1986?), I had learned from my bio professor (Dr. Bob Love, great professor) that partially hydrogenated fats were just as ‘bad’ as saturated fats. That was the extent of the knowledge then, and I told them doughnuts were not good food. The couple left, and my boss popped up and told me he’d fire me if I ever turned away a customer like that again.
    Now, after eating low carb for 2.5 years, I can honestly say that I’ve gotten most of that eating pattern back. Maybe I’ll have a can of sardines for brunch, but not much else until dinner. I am beginning to truly believe that Homo sapien sapien can exist on meat and fat alone.
    Hi Karen–
    Thanks for the stories of your life as a baker. I fear that I would have succumbed to the freshly baked donuts way more often than you did.
    Like you, I believe that we humans can do just fine (better than fine, actually) on a diet of meat and fat alone.

      1. The much-villainized and misunderstood uric acid is upregulated and replaces nearly all of vitamin C (ascorbic acid)’s job when vitamin C is low, and very, very little vitamin C is lost on a no-carb, no-plant diet (some plants have a lot of vitamin C, but plant anti-nutrients and high carb intake depletes your vitamin C reserves quickly).
        The small amounts of vitamin C in muscle meat and liver, combined with increased uric acid secretion, seems to be adequate enough. Tribes like the Masai and Inuit have diets which are almost/completely devoid of plants, and yet they seem to be fine.
        (funny thing is this also *might* be true of manganese, mostly found in plants but replaced by magnesium in cases of deficiencies… )
        We didn’t evolve to not produce our own vitamin C and then survive millions of years of low/zero-carbing for no reason you know…
        At worst, there are always supplements.
        Just don’t eat high-carb & low-vit.C at the same time; you’ll get scurvy

  35. Great post!
    I’ve been Paleo for over a year, and I’m a recent zero-carber. Since going carnivore, I’ve found I naturally eat less often – usually brunch around noon and then dinner around 8 or 9. Prior to this I was eating (low-carb) every few hours to fight hypoglycemia, but since zero carb I’ve had zero hypoglycemic symptoms, terrific energy, etc.
    Anyway, I’m lucky enough to have a very flexible schedule, so I’m thinking I could make this even easier by shifting the magic hour to 2pm. That way on the ‘eat after 2pm’ days, a decent sleep-in until noon would have that day not feel like a fast day at all, and on ‘eat before 2pm’ days, breakfast and lunch would be eaten. I’d still have to skip that dinner, but since I’m already naturally lasting from noon til 8 or 9pm, eating at 2pm would probably see me through until I was asleep, dreaming about my 2pm brunch!
    If I try it, I’ll let you know how it goes. : )
    Hi Paleogirl–
    Please do let me know how it goes. I’m keenly interested.

  36. Hi Dr. Eades,
    What about introducing more randomness to it? ie putting about 1-3 fasting days (no eating from 7am-7am) randomly into a week, or even just one fasting day randomly in a week? Another idea would be to do yours and MD’s schedule randomly, ie 3 days on, 3 days off, 2 days on, 1 day off, 4 days on, 5 days off, etc, etc. This sort of random eating pattern is something Art Devany is a big fan of, as it is likely most closely related to how our paleo ancestors ate.
    I think I will try that (especially if my wife agrees) and I’ll let you know how it goes. I’ve never skipped more than one meal in my whole life. I’m an avid exerciser and can have about 4% body fat, carbs or no carbs, without a whole lot of effort, so I’ve always been a little afraid not to eat.
    Anways, we’ll see how it goes….By the way, I’m glad to have read some of the above posts. I have a three year old, and have been known to do the old “You can get down from the table after you finish eating” thing before. It’s tough, if there ever was a wannabe vegan, it’s him. He’d prefer to just eat mango 3 times a day.
    Hi Daniel–
    I don’t see any reason that the random approach wouldn’t work. In fact, it probably is more in keeping with our Paleolithic past.
    Let me know how you do. And don’t worry about you’re kid. I did the old “you can’t leave until you’ve cleaned your plate” myself and they don’t seem to be any the worse for wear. I’m going to revise my stance with the grandchildren, however.

  37. Thanks for the insightful blog post Dr Eades
    I eat only one low carb meal during the day during the week. On weekends I eat both days low carb.
    I have been doing this on and off for a few years and whenever I do, I lose weight and I have more energy (in fact, I did the ‘eat one meal a day’ regimen eating non low carb a few years ago and also lost weight and had more energy).
    Unfortunately I haven’t noticed that it has an effect on my eczema (which is rather chronic). I am curious to know if there low carb foods that I should avoid to lessen inflammation? I eat mostly meats, fish, eggs, spinach, broccoli and cauliflower. Cheese, cream and milk are present but not in huge quantities.
    Hi Sam–
    Glad to hear that you’ve done well on the IF regimen.
    As to the eczema…I’ve read a couple of studies in which researchers have put people with allergic problems on a diet of meat only for a while. You might want to try that for a week or so to see if the eczema gets better. If it does, then start adding one food at a time back in until you get a flare up and you will know what caused it. If going on the full meat diet doesn’t help, then you’ve probably got an eczema of non-allergic origin.

  38. Regarding the orthodox christian fast – you don’t eat animal products. As far as I know you can have oil as its not of animal origin.
    The fast sounds excellent – I must give it a go. Perhaps it may help my hashimotos.
    Hi Sue–
    The IF regimen should improve any kind of autoimmune disorders Hashimoto’s included.
    Keep me posted on how you’re doing with it.

  39. Dr. Eades, this subject more than any other in your blog has piqued my interest. I’m going to show it to my husband and let him read it and see how he feels about partaking of this regimen. It really sounds doable. You mentioned that drinking water, coffee, et al is OK during the IF regimen, but what’s you’re opinion if one were to partake of whey protein drinks/shakes during the fast part of the schedule? Would this be considered a meal or as a liquid? Would drinking a protein shake during the fasting portion (say, during the BF or Lunch) defeat the whole purpose of this exercise?
    Hi Marlene–
    The only things you can eat (or drink) during the fast portion of the day are food without caloric content. If you eat calories, whether they be from whey or anything else, you really aren’t on a fast; you would be following a low calorie diet. What apparently makes this regimen work is the period of time one goes without food. Adding a little food during those periods would defeat the purpose.
    Let me know how you do if you try.

  40. Perhaps I missed it.
    I know you mentioned coffee as a beverage, and realize, if I remember reading correctly (previously) that you don’t eliminate caffeine, so I am wondering if a person could make a beverage by freezing coffee in ice cube trays, and then shredding it in a blender – having a sort of iced coffee/frappichino (sp?) effect, with no particularly adverse consequences. This, of course, would still involve it remaining black, unsweetened, but would give variety.
    I guess perhaps the question should be more directed to temperature – is there a benefit to hot or cold, or is it a personal preference?
    Hi Constance–
    I think the hot or cold is a personal preference. If there are no calories it doesn’t matter if it’s boiling hot or freezing cold.
    Let me know how it works for you.

  41. Sorry to post another question Mike on the same subject and thanks for the answer BTW about NOT losing muscle mass by adopting an IF approach to eating. I’ll monitor this with my $1750 Bioanalogics body comp device and let you know!
    Q: Does IF include all beverages? Coffee, water, etc?
    Hi Fred–
    No, beverages can be included during fating periods as long as they are non-caloric. Black coffee, water, club soda, etc.

  42. Dr M Just curious-have you ever had a post with more comments? If so which one? If, of course, you can remember with al the thousands of words you have written! This one has been really interesting.
    Hi Tess–
    I was just asking myself this same question as I type out the responses to the 23 or so more that have stacked up while I was out today. It is indeed the post that has garnered the most comments by far.

  43. Mike, I’ll have to dig into my files. I’m pretty sure this came out between 2000-2002. I was still in Sweden when I read this and the article may not have survive the relocation!
    As for the number of generations, I’m pretty sure that was the number (I was also amazed), but now that you’re asking, I have this ‘fly’ in my brain that wants to make sure the facts are right… so now I must find that study again!!!
    In the mean time, I found a ‘jewel’ for you that I’m sending by e-mail; and article on IF and longevity in Drosophila written in 1928.
    Thanks, Gabe. I’ll keep an eye out for it.

  44. Hi Dr. Eades,
    I belong to a LC support forum and some of us there, after reading your blog, have decided to give IF a try. Some of us have already posted comments here. We started a support thread (, where you or anyone else interested, can follow our progress, if you are so inclined.
    Hi Cathy–
    I’ll keep an eye on it. Thanks for the heads up. Wish everyone good luck from me.

  45. I lost 85 of 100 lbs using a variant of the techniques outlined here. (I’m 5’10”)
    Basically, I controlled caloric intake so each day was +/-200 calories of a 1200 calorie baseline. (ie, Day 1 = 1200 cal, Day 2 = 1000 cal, Day 3 = 1400 cal.) I went from 255 lbs to 170 lbs over a 1.5 year timespan w/a slight increase in exercise. The loss occurred between age 17 and 19. I’m now age 52 and my weight has varied +/- 5 lbs over that period until recently. (I lost another 15 lbs switching to a lower carb regime over the last 2 years due to IGT dx. Total loss is 100 lbs.)
    I’ve been accepted to the National Weightloss Registry and am happily filling out a whole bunch of surveys. 🙂
    Hi Steve–
    Make sure to tell the bozos at the National Weightloss Registry that your maintaining on a low-carb diet. They’ll hate it.
    Congrats on your success.

  46. Dr Eades Sir..this is scandalous.
    I put it to you Sir that suggesting that we go without our victuals for some part of the day is an outrageous claim.
    I shall consult the lawyer i do not have.
    Nice one Brother..thanks the effort.
    Hi Simon–
    I was beginning to worry. This is the post you’ve been whining for and I didn’t hear from you for almost 36 hours.
    Glad you enjoyed it.

  47. Dr. Eades,
    Art Devany has mentioned several times that 15 hours with no food is all it takes to get the benefits of intermittent fasting. I’ve looked but can’t find anything in the literature that supports that time period. In your next article on fasting could you address this? I’ve tried it and it’s really not that hard to do. I eat dinner on one day and then just skip breakfast the next day and I don’t eat anything in between.
    Hi David–
    I don’t know where Art DeVany got his info on the 15 hours; maybe from a paper I haven’t read. The authors of the study I quoted in the post didn’t really even IF; they simply consumed fewer calories on alternate days. I don’t know if 24 hours is a magic number or not, but it seems pretty easy to schedule that way.

  48. Dr. Eades,
    My question regarding this topic:
    I see on many low carb boards the topic of “starvation mode.” There are a lot of opinions out there that your body shifts into this mode if you don’t eat regularly. I have also seen lots of eating plans that want you to eat small meals throughout the day. I think this is just one of those thoughts that is repeated over and over and people begin to think it is a fact.
    What is your opinion?
    Hi Amy–
    I posted on this sometime in the past. There is a ‘starvation response’ that kicks in after one goes without eating for a day or so. Insulin goes down, glucagon goes up, fat is converted to ketone bodies, which are burned for energy in many tissues in place of blood sugar, protein is converted to glucose to be used by those tissues that can’t use ketone bodies. That, in a nutshell, is the starvation response. Everything that happens is good. Insulin goes down: good. Blood sugar levels go down and stabilize: good. Many tissues turn to fat and ketone bodies for energy: good. The only bad thing that happens in the starvation response is the loss of protein (often from muscle) to make glucose.
    The studies I posted on previously showed that the starvation response can be initiated by restricting carbohydrates. It’s not the lack of food in general that initiates the response; it’s the lack of carbohydrate. So, if one reduces carbohydrate intake all the good parts of the starvation response kick in while the protein in the diet serves to be the substrate for the conversion to glucose, leaving the muscle and other protein structures intact.
    Hope this helps.

  49. Mike,
    If I have it correct the timing you used was:
    Day 1: eat until 6:00 pm
    Day 2: eat nothing but dinner around 6:00 pm
    Day 3: eat breakfast and lunch nothing past 6:00 pm (if your lunch was at noon you could stop there as well?)
    Day 4: fast until 6:00 pm
    repeat etc..
    Hi Randy–
    You got it.
    Let me know how you do.

  50. I made it 24 hours just fine! It wasn’t that hard. For the last 6 weeks, I’ve been eating near purist level PP and < 30g carbs. I’ve lost 12 pounds (with 85 to go). I did 1hr weight training this morning and then ate breakfast after that.
    I will try the suggested rotation over the next week or so. I have a blog about my weightloss journey so I will keep that updated. I’m a type 2 diabetic and my blood sugar has been stable at 98 for the last several weeks, but I want to get it to 83. Hopefully this will do it. Thanks Dr. Mike.
    Hi Joyce–
    Good luck. Keep me posted. I hope it works for you.

  51. I too did this in school and nicely maintained my weight. I’d have no solids 1-3 days in a row. I found that if I went past 3 days I’d start to feel it, but 1-3 were no problem.
    I’ve also used a fast to get back on LC after a binge.
    I am going to seriously consider this.
    Thanks for all the great posts!
    Hi Alcinda–
    Thanks for the kind words. Keep me posted on your progress.

  52. Dr Mike
    I just reread your answer to my comment about supplements and realized that it doesn’t take into account the mag citrate that I take every night before retiring. Since it’s just one mineral and no calories, will it interfere with the fast?
    Hi LC–
    Don’t worry about the mag citrate. It, like most other vitamin and mineral supplements, is non-caloric.

  53. As an avid weightlifter and general physical preparedness buff I have always been concerned about not getting enough fuel for the fire. At the same time, while strong and aerobically fit, I do not have my body fat where I want it. I’m starting this IF today with your parameters doc (6 pm to 6 pm). I just realized what hurts me is when I try and get food every two hours every day is that I tend to overdo it especially if I down a few too many carbs. I actually do well during periods of non eating. I feel more alert and less cranky. Mentally if I know I can eat at some point, even if is within a window, I can hold on. Well here I go, I’ll keep you posted, especially with regards to my strength training progress and body weight. I’m currently 230 lbs with about 16% BF using those home calipers…
    thanks for the inspiration in the article
    Hi Randy–
    Good luck. I think you will find it pretty easy. And the meal at 6 PM tastes really good.

  54. i’m starting tonight! one more question:
    on your eating day, do you eat all day long or eat a couple very high calorie meals -or does it matter?
    it’s hard for me to eat that much at one time. is it important to get double the calories in, i mean, if one ends up not eating that much more than they regularly do on an eating day, is that going to reduce the benefits. is the feasting part as important as the fasting?
    Hi Susan–
    You can eat however you want on your eating days. Lots of little meals or a few big meals or big meals interspersed with little meals. You don’t have to try to eat two days worth of calories in the one day–just eat until you’re not hungry and leave it at that. What’s more important than how many meals you eat on eating days is that you NOT eat any meals on fasting days. That’s what makes the process work.
    Keep me posted.

  55. Hi Dr. Eades! This is Robb Wolf from Chico CA. I’m a friend/former student of Prof. Cordain’s. We have been looking at intermittent fasting for high-level athletes for over a year in our strength & conditioning practice. We have published some of these results in our magazine the Performance Menu ( Issues 6, 16 and 18 concern intermittent fasting. One may download one of these issues for free.
    Hi Robb–
    Thanks for passing along the info for all. I’ll take a look.

  56. Wow, lots of comments on this one! I’m going to give it a try. Back in my young and skinny days when I lived by myself, I kind of did a variation of this. Never ate dinner except when going out during the weekends and that more or less might have been my only meal of the day. What changed for me was getting married to a guy who is firmly entrenched in the concept of three meals a day and believes that some sort of dessert should be a part of at least two of them. Strangely enough, I never really noticed the weight I was gaining and when I think back then to my complaints of my clothes mysteriously shrinking, I have to wonder what universe I was living in that I didn’t see what was going on. What brought it all to a grinding halt was when about two years later in a space of a week, three different people asked me when the baby was due and I wasn’t pregnant. Heh, that’s when the mist cleared from my eyes and I realized I was fat. I started exercising, cut out all the desserts, ate the usual low-fat crud and did lose a decent amount of weight but then I got stuck about 10 pounds away from my goal and nothing changed that for several years. Then one day I stumbled onto a LC website which in turn led me to Gary Taubs’ Fat Lie article which then led me to several other sites and articles and then ultimately to “Protein Power” and the rest is history. Giving IF a try seems like the next logical step for me to take.
    I do have one question, though. I only drink one cup of coffee a day in the morning and it has cream in it as I simply cannot stomach the stuff straight (same goes for black tea.) Is this ok or should I look for an alternative source of caffeine on those off mornings? Thanks!
    Hi Esther–
    Well, I would tell you to just buck up and be a man and drink the coffee black. Except for the fact that MD is the same way; she can’t (won’t) drink her coffee without cream. I’ve tried without success for years to get her to see the light. When we did the IF, she drank her coffee with cream on her fasting days, so even if I won’t, she will give you dispensation to do the same. (She drank one or sometimes two cups of coffee with cream in the morning, but no more than that.)
    Good luck. Keep me posted.

  57. Hi Mike, this first part of my comment is off topic, and I hope you and everyone else forgives me for doing this.
    PPLP was my introduction to diet and autoimmune response. From there, I’ve devoted a lot of time to investigating autoimmune disorders and the association it has with gluten and casein intolerance.
    For the person with ankylosing spondylitis, and the person with chronic eczema, totally eliminating gluten from my husband’s diet caused total remission of his ankylosing spondylitis. He’s been flare-up free for 6 years, and his systemic inflammation is gone. He also had chronic eczema associated with his AS disorder. He hasn’t had eczema now for the same length of time. He also hasn’t had a migraine headache since he stopped eating gluten. I have corresponded with many people that have also experienced remission of their autoimmune disorders when they eliminated gluten from their diet. Some people have had to also eliminate casein from their diet to experience remission from their autoimmune disorders.
    There has to always be one in the crowd that has to be different….I think I have already been doing IF. I’ve happily eaten only one meal a day (dinner) for the past 4-5 years, after switching to strict low carb over 7 years ago. But it hasn’t helped in weight loss or improvement of insulin resistance or Phase 1 insulin response. According to my fasting glucose numbers, I’m still heading down the road to diabetes. I do have PCOS. I am not diabetic yet, but it seems I can’t stop the progression to diabetes. And, I have acquired serious difficulties in cognitive function (memory loss and inability to concentrate and focus) and my energy level has dropped tremendously. These symptoms suggest hypothyroidism, but according to my thyroid tests, my thyroid function is normal.
    For me, I don’t see how doing “IF” is going to do anything different to improve my health if only eating once a day for the past 4-5 years hasn’t helped! I certainly don’t know yet if eating one meal a day for 4-5 years has increased my longevity…..
    I don’t mean to be a cynic or be negative about it all. It’s just that my experience with low carb and IF (if one meal a day is considered to be IF) hasn’t produced the expected “benefits” for me. Going back to high carb low fat isn’t the answer either, as that will greatly hasten the progression to diabetes!
    Perhaps IF only benefits those people that do not do low carb in the first place, and those that still eat grains and gluten.
    Hi Georgette–
    Thanks for the discourse on anti-inflammatory disorders and gluten and casein. It is very true that both of these substances can (and often do) cause serious autoimmune problems through the process of molecular mimicry.
    As to your weight-loss and diabetic history, I find it all very puzzling. The low-carb diet, especially a low-carb diet taken in IF structure, is the gold standard for treatment of diabetes and obesity in a system that is operating properly. (It would seem to be obvious if someone has diabetes or obesity that the system isn’t operating properly, but that isn’t the case. Diabetes and/or obesity are responses of a properly operating system to the incorrect diet) If the regimen doesn’t work, then the system must be malfunctioning. Were I you, I would seek out a competent endocrinologist for a thorough evaluation. In reading your history a number of problems come to mind–cyclical Cushing’s, pituitary adenoma, a glucagon-secreting tumor (usually benign), multiple endocrine adenopathy (MEA), just to name a few–all of which can be tracked down and treated by someone who knows what he or she is doing.
    I hope you ferret out the problem. Keep me posted.

  58. Hi Dr. Eades,
    I will pass along your good luck wishes on our thread. Several people have successfully made it through their first fasting day.
    I started my fasting tonight, so I hope tomorrow I can manage to make it through the remaining 24 hr. I was planning on making a batch of Power Muffins (cranberry, after reading MD’s blog the other day) this weekend. Now I know I will have to wait until the fast is done before I attempt this. I think they would be too difficult to resist after smelling them baking.
    One question about supplements. I have decided to take all my supplements at night now (before the fasting begins or just after it ends), instead of taking some in the morning and some at night. The reason for this is that the cod liver oil (was 1 tsp 2x day, which is 90 calories total) and krill oil (2 capsules in am), have calories. I’m not sure if the vitamin E has calories. Does this make sense, in terms of not having any calories during the fasting period?
    Thanks again,
    Hi Cathy–
    I don’t think the minuscule number of calories in fish oil/krill oil is going to foul anything up with the IF. Were I you, I would take them whenever most convenient. When MD and I did our various versions of the IF it never occurred to us to change our supplement regimen.

  59. In a previous blog, you suggest eating less than 100 grams of carb a day to stay in some degree of ketosis.
    If you eat every other 24 hours, would that suggested maximum carb intake stay the same (100 grams during the non-fasting period, 0 during the fasting)?
    Along the same lines, if I eat a multivitamin that’s meant to be taken twice a day, should I double the dose during the fasting period, or keep the doses the same?
    Hi imsovain–
    The virtue of IF is that one doesn’t have to worry so much about counting carbs, calories or anything else. The every other day nature of the thing obviates all that. If you want to stay on the same low-carb regimen as usual, just stick with the 100 grams per day. You won’t have to worry about whether or not you’re in ketosis on the fast days–you will be.
    Take the supplements on your regular schedule as if you weren’t IFing.

  60. she drank her coffee with cream on her fasting days, so even if I won’t, she will give you dispensation to do the same.
    That one had me laughing out loud. I’m weird with my coffee, viz. add lots of stuff like hazelnut butter and/or shredded coconut.
    But now a few more questions. You’ve already addressed the muscle loss Q. Yet, from the literature I’ve read, I vividly remember that 2 meals are very important. 1. breakfast for starting up metabolism and make one lose fat more easily. 2. dinner for retaining muscle mass. So, I’m hesitant to cut out either one of them, will start with 2 meals/day every 12 hrs at 10 am /10pm first to ‘test’ the waters.
    Second Q: how much does metabolism slow down?
    From my private experience I know that I’d lose weight very rapidly in the first week of cutting out calories and then I’d stall completely.
    From the various bodybuilding-related literature a 20% calorie restriction seems to be the only real sustainable one to produce ongoing fat loss. Fasting for 24 hrs would make it harder to eat enough, isn’t it. Eating several meals/day on the non-fasting days would indeed make things more easy.
    Third Q: I’d assume/presume that it’d be the best strategy to work out after having had 2 meals like working out after breakfast rather than at the end of a fast? Why would some people do it before? Growth hormone output as suggested in Natural Hormone Enhancement by Faigin doesn’t seem to be as important as it is said to be.
    Hi Yvana–
    Metabolic rate is more correlated to body weight than anything else. A number of studies have been done with subjects in metabolic chambers, and just about all have shown that the subject’s weight pretty much established their metabolic rates, not other factors such as meal timing, etc. So, if you lose weight, you decrease metabolic rate.
    There is a thermic effect of food. In other words foods require energy from the body to deal with them. One of the nice things about the IF is that calories can stay pretty much the same–providing the same thermic effect of food–and still allow weight loss and improvement in all kinds of health parameters. Cutting calories by eating less on a daily basis wouldn’t necessarily do the same, and you would lose the thermic effect of the calories that aren’t consumed.
    Good luck.

  61. Mike,
    OK last one – what about all the supposed dangers of skipping meals? Dr. Schwarzbein as well as many other ‘experts’ talk about this in their books. She claims that skipping meals is very bad for hormonal tone and further damages one’s metabolism. True or false?
    Hi Fred–
    I don’t believe it is true. When I posted on IF I simply summarized the research data out there, which shows many, many benefits in animal models and in the few human studies that have been done. This isn’t a matter of opinion; this is what the research shows. Why does it work this way? Who knows? The fact is that it does. Someday someone will probably get around to figuring out why. My bet is that it will have something to do with our genome that was created over millennia of natural selection to operate optimally on low-carb, high-fat, high-protein diets taken in on a variable timing pattern.

  62. Just wanted to say good luck to all those that try IF regime. I personally do Calorie Restriction and have done for 2 years, with amazing results that puts me at very low risk of many diseases (have had lots of tests done). I am sure that IF will have similar benefit’s for you, and may exceed CR in some areas. If you do carry this out long term you could also be significantly extending your lifespan also.
    I’d also be very interested if anyone here could monitor their health by getting a baseline blood test done now, and then one later on sometime.
    I am well aware of the benefits of CR as I’ve read many published papers on human, rodent and non-human primate studies, but am unsure about what effects IF has in terms of glucose, insulin, cholesterol, CRP, blood pressure, temperature and so on.
    Hi Matt–
    Thanks for the update on your CR experience. Not many people have what it takes to do such a thing over the long term.
    The studies on IF pretty much universally show that all the benefits of CR plus some can be had without calorically restricting as long as food is taken in every other day.

  63. Sir ..ref whining and whinging !
    ref 36 hrs..i’m building a Yurt/Ger.
    Also i have a gem which i’ll try and post later this w/e on what happened to Alexander Selkirk when he was rescued after 4 years and what happened to him when he ate the ‘fud’ on the first shop, sorry ship, he left the island.Rather telling vis him seeming to live on goat meat for 4 years
    Hi Simon–
    The dictionary (the OED, no less) lists both whining and whinging to be acceptable. Personally, I would rather be known as a whiner than a whinger, but others may differ.
    Can’t wait to hear about A. Selkirk.
    And, uh, what is a Yurt/Ger, and how does one build one?

  64. Dr. Mike,
    I very much appreciate your comments. I am truly at my wit’s end with what I’ve been experiencing. I do believe I have something going on, but I don’t know of any doctor in my rural area that I can trust, especially considering the major clinic is an HMO, and that’s where my health insurance is through.
    I have wondered for the past year about Cushing’s, as I have many symptoms that match it. And, a pituitary adenoma could be a factor, since that can cause Cushing’s, too. No one else in my family has symptoms of it.
    Do you know of any good doctors in the Spokane, WA area? I’d even consider going to a doctor in the Seattle area or even Portland, Oregon, if I could actually get help with what’s happening with me.
    Again, thank you for your comments. I will be happy to keep you posted. I just don’t know when this will all be resolved!
    OK…back to the regular scheduled programming….. 😉
    Hi Georgette–
    I do happen to know of someone in Spokane who could help you. My former nurse, Debbie Judd, is in Spokane and has a metabolic clinic along with her physician husband. I checked with her and they would be happy to hear from you. Their contact info is:
    The Metabolic Institute
    910 W. 5th Ave Suite 660
    Spokane, WA 9920
    Good luck.

  65. Sir away with you..are you serious you don’t know what a Yurt is ?
    Surely you’ve seen piccies ?
    Originated in..well there’s much debate but they are still the preferred shelter in Mongolia.
    One makes a crown (or tono in Mongolian) out of whatever wood…its circular, made of 8 1/4 pieces staggered for strength 3 inches depth and 6 wide with 52 equally spaced holes drilled at 33 degrees on the outer surface(diff designs of course have diff configs ) it also has circular bridges from/to all 4 points.
    One then makes 110 6ft batons( routed edges, so nice and smooth) all drilled differently. One makes 4 lattice work frames by affixing said baton with 4mm cord(trad leather or twine….the self supporting structure is basically unchanged in design for 2500-3000 yrs)
    One makes roof poles to fit in the holes and sit atop the lattice work drilled with a loop of cord thats fits over one ‘v’ of the lattice.
    One then makes a cover out of rain proof and fire retardent canvas. One lines it with felt if Wintering in it (good apparently trad down to -50 in Mongolia)
    Takes about 1 hr top erect and a reasonably made frame is suggested to last 100 years if moved a few times per moved say once weekly good for 20 plus years. Trad given as wedding gift.
    Am halfway thru the lattice work having finished the crown. Not being a wood worker this has been quite the learning curve and the crown being the hardest part is what i tackled first.
    Since living in Africa and the years afore where i trudged around the world with tent i really adore being outside and Ger is wonderful.Spacious, light, deeply relaxing blah blah
    Ours is 16ft diameter, doug fir. The crown is a bit of a bollocks-up as its a bit chunky(christened McTono!) but am told by master Ger makers that its fine as the extra weight is needed anyways to puch down on the roof poles and eq. distribute the weight on the lattice work.
    Add one Yak pulled cart with almost circular wheels and you’re good to go.
    So there you go !
    Hi Simon–
    Thanks for the description. I actually did know (sort of) what a yurt is; I thought you were abbreviating something in your previous post.

  66. i have been on the Warrior diet for 4 years- where i fasted all day and then ate one big meal at great for me
    Google;Warrior Diet
    Hi Rygar–
    Thanks for the update.

  67. Hi Doc!
    I read through the posts and noticed a few questions we have had some experience with. The state of ketosis is intimately tied to insulin sensitivity…if one is insulin resistant ketosis may be difficult or impossible to reach. It is interesting to note that ketosis, even under short term caloric restriction, shows a potent protein sparing effect. Some of the work by Matson shows a pronounced increase in IGF (insulin like growth factors…at least in mice) AND significant increases in pulsitile growth hormone release. We have several athletes who have endeavored to eat a caloric excess in conjunction with 16-20hr fast and have increased lean muscle mass and performance in both anaerobic and aerobic activities. Intermittent Fasting shows many of the same characteristics as anaerobic sprint intervals with regards to preference for fat as a fuel source and acute adrenal cortical stress response which appears to underlie much of the favorable adaptations. Our athletes have used a cyclic low carb diet with primarily “paleo” foods. This appears to be of benefit not only to endurance athletes but power athletes as well. Very interesting stuff.
    Hi Rob–
    Interesting stuff indeed! Thanks for the informative post.

  68. Hi Dr.Eades I want to start Monday on my fast.
    Im a type 2 diabetic taking metformin 2x’s a day.Question do i still have to take it when im fasting? My DH takes meds for high blood pressure does he continue that too? he thinks if he takes his supplements on an empty stomach he will be sick. would appreciate any comments.
    Hi Stell–
    Unfortunately, due to state medical laws, I can’t give you specific medical advice. My recommendation would be that you check with the physician who put you on the medications.

  69. Well, I made it through the first 24 hours. Longest I have gone without food my entire life. One thing it did was clue me in to how often I tend to eat, even small amounts, and how much I focus on food..too much. Other than that it was not too bad. I seemed more alert during the day.
    When it was time for my 6 pm feed I was at work (I’m a police officer) so I had a blimpie turkey sandwich. More carbs than I usually would, but Dr. Eades said it was ok from what I was reading. It was the best sandwich I’ve ever tasted..I ate it fast and was still hungry. I just got home from work at 2 am, will sleep and wake up to attack breakfast and lunch and whatever else for the feed day. Thats my first day of IF…went ok, I survived…and feel pretty good.
    Hi Randy–
    Way to go! Thanks for the update. And you’re right, the meal at 6 PM tastes great almost no matter what it is.

  70. Dr. Eades,
    I wasn’t aware of your blog until yesterday after it was linked from the message board, and from what I have seen you are a first rate guy. First, you praise the benefits of IF, then I read your post below that and see you defending saturated fat – it was at that moment that I knew I would need to check your blog daily! I’d also like to say that it is very generous of you to comment on all the comments. Also, I would definitely get in touch with Robb Wolf (above) if you want to know more about IF success in actual practice. I learned about IF some time ago from Robb’s writings and have been following it with great success.
    Keep fighting the good fight,
    Hi Neal–
    Thanks for writing. I don’t know how much longer my generosity can hold up if I write many more posts inspiring a zillion questions. Thanks for the heads up on Robb Wolf.

  71. Dr. Eades,
    I’m an avid reader of your blogs and this is my, first post 🙂 Your entry about IF is timely. I’ve been considering CR but it doesn’t seem realistic, whereas IF does. My question — I am currently nursing a 1 year old, and was wondering if you knew about any effects of IF on nursing.
    Hi Cciele–
    I haven’t read anything on IF and nursing, but I can’t see any harm in it as long as you keep up your caloric intake on the feeding days. I’m assuming that your child at one year old is ready to start some solid food anyway. Right?

  72. Hey Dr. Mike,
    Jimmy Moore from the “Livin’ La Vida Low-Carb” blog here. I am VERY interested in trying this IF plan for myself to see if I can drop another 15-20 pounds after my 180-pound weight loss on low-carb in 2004.
    My question is regarding my workout schedule. I usually get in a 30-45 minute cardio workout on the elliptical machine during my lunch hour at work. I’m concerned on the days when I don’t eat until suppertime that I will not have the energy to exercise.
    What do you suggest I do?
    THANKS for the outstanding topic and for all that you and MD do for the low-carb community. We appreciate you so much!
    Jimmy Moore, author of “Livin’ La Vida Low-Carb”
    Hi Jimmy–
    I would give it a try to see what happens. I doubt that you will run out of energy, but if you do, you might want to exercise only on eating days.
    Keep me posted on your progress.

  73. I gained a tremendous amount of weight in my 40s – during a time of trauma/stress and overwork. I was told it was because I was on the “sumo wrestler” diet – not eating anything all day and then collapsing in the evening and eating way too much. Granted, there were lots of carbs! I haven’t had any success losing weight on any plan – low cal, low carb – I just seem to lose and gain the same 15 pounds every year. I am now inching towards type 2. I’ve struggled to get into the habit of eating breakfast – especially a high protein breakfast – and on a positive note I now exercise regularly and take good supplements. Would someone who gained weight on this schedule before possibly benefit from adopting it in a different way? Because I always feel so much conflict when I eat, it would be a blessing to just let it go 24 hours at a time.
    Hi Patricia–
    What have you got to lose. Give it a whirl and see what happens. If going without food for 24 hours holds no terrors for you, it might be just the regimen that works. If I were in your shoes and doing the program I would eat low-carb during my eat days.

  74. No response required if you’re busy doctor; I can’t believe the effort you put into this. I’m a blogger (a lousy one at consistency)… I know. Perhaps at your convenience you could address this in the future if busy now.
    What about people who are just starting out on lowcarb. I did a brief (>1 month) lowcarb years ago. Given it essentially changed my life (about 10 major health issues cleared up miraculously after 10 days — probably from ditching all gluten and milk during the period) I can’t explain why I went off it aside from “sheer laziness and working 120 hours a week while single mom-ing a small child” just made having to worry about planning and cooking too big a pain. Now I’m going back on it. I’m severely obese (still) and just starting out here, so I’m wondering —
    1. Would your IF idea be any kind of a problem during an Atkins-like induction period, do you think? Would this situation change your feelings on it? Most the commenters here (and you and the missus) sound like you’ve been doing LC for eons.
    2. I gained well over 200 lbs in less than 2 years, many many years ago. Actually my whole family (females only for some reason) tend to do this in the mid-20’s; I denied it and it happened anyway. (I wonder if insulin resistance can kick in at a certain age genetically?) The weight gain period was eating mostly 1 meal a day, of megacarbs before collapsing into my 4 hours of sleep. Always sitting, super high stress, but I attributed this mass gain in part to the only eating once a day thing and my metabolism just shutting down. So it’s been fascinating to read your comments (and the comments of others) in favor of 1 meal a day.
    I still tend to eat once a day (around dinnertime), though I grant junk, and I don’t lose weight–but at 467 as of today, you’d think I’d have to eat a refrigerator a day to maintain that, sheesh. I am guessing that “it must be relatively lowcarb” is the entire difference!
    I love fasting. I used to do it just for fun (obviously insane at a young age) when in my teens (really amps up the ‘esoteric awareness’ bit). Can I incorporate your IF ideas into my induction, which is going to last… oh, at this weight, the rest of my natural life probably… without it being a problem?
    Best. PJ
    Hi PJ
    I have seen no published studies showing how the IF would work for someone weighing 467 lbs. That doesn’t mean that it won’t work (I figure it probably would); it just means that as far as I know there is no collected data.
    I (and many other physicians using LC diets) have had a number of patients with weights in that range who have done very well on Protein Power-style low-carb diets. I would caution you, however, before starting such a regimen that if you are on any medications or have any secondary health issues, you must see a physician skilled in the use of low-carb diets. These diets are extremely potent therapeutic tools for weight loss and health improvement, but they often require early medication adjustments.
    Good luck. Keep me posted. Find a capable doc.

  75. This sounds very interesting. When I was a child my mother used to freak out because I wouldn’t want to eat breakfast and often went without; as an adult while trying to “eat healthy” I have to force myself to eat breakfast. I’m just not hungry in the mornings. I recently came across some of my old journals from the mid-nineties when I was extremely poor, and I was only eating once a day … but I was in pretty good health and the thinnest I’ve ever been and I don’t remember being particularly hungry. I think a lot of us forget what real hunger feels like in this era of 24-hour food on demand. I know I have. A schedule like you and Mary Dan have set up sounds doable, and I’m going to try it.
    Hi Patricia–
    Good luck with the IF. Keep me posted.

  76. Dr. Eades:
    A most interesting subject indeed. I too am an avid reader of your blog, but this is my first post.
    Reading about IF, I just realized that I was most successful losing weight on what seems to be a variant of IF, though it was not done purposefully.
    What triggered my thoughts was the discussion about length of fast-was 15 hours enough.
    Here is what happened with me. I was following a strict Protein Power low carb plan, and would routinely go from after dinner[at around 630pm] till close to noon next day without any calorie intake, so had a 16 to 20 hour window each day without any calories. I lost weight rapidly and felt very energized. My wife continued to eat three meals a day, also PP, and struggled mightily with weight loss.
    Do you think that eating pattern was close enough to IF to have pushed the results I had? [70 pound loss in 11 months]
    I am definitely starting a real IF today.
    John Bailey
    Hi John–
    Keep me posted on your progress. I don’t know if 24 hours is the magic number or not. Could be 15 could be 30. Until a number of studies are done, I guess we won’t know for sure. MD and I settled on the regimen that we did because it breaks up the day nicely and gave us something to eat every day.
    Good luck.

  77. I have ate this way for years without knowing I was doing my body good; my husband would often harangue me for my eating habits. I will be showing this to him immediately as he thinks everyone needs to have three meals a day, everyday. I also want to add that he is borderline obese, has high blood pressure, high cholesterol, and diabetes. If, by some miracle, I can get him to try eating this way, I will let you know how it turns out.
    Thank you.
    Hi Kathy–
    I’ll be eager to hear.

  78. I will certainly give it a go, Dr. Eades. One more question and I’ll be done.
    Does a protein shake count as food or drink? In other words, can I drink an Atkins shake on the mornings I am supposed to be fasting or not?
    THANKS again! I’m looking forward to seeing how this works. Take care!
    Jimmy Moore, author of “Livin’ La Vida Low-Carb”
    Hi Jimmy–
    Since and Atkins shake contains calories, if you took it in you would not be fasting. Many people don’t realize that caloric liquids–as far as the metabolic system is concerned–are no different that solid foods. One of the jobs of your teeth and your stomach acid is to convert solid foods into liquid foods. So it doesn’t matter whether it’s a protein shake or a rib-eye steak when it goes in your mouth, by the time it reaches your small intestine where it is absorbed and kicks off all the metabolic processes it is a liquid.
    Hope this helps.

  79. A couple of questions for you Dr. Mike….
    First, if it’s not too personal a question, do you mind sharing why you and your wife stopped doing IF given all the benefits you list? Was it just too inconvenient in the long run?
    Second, I thought one of the greatest benefits of the CRON lifestyle was the extended lifespan, but unless I missed it, I see no mention of that as a benefit of IF. Has that possible benefit not been studied or just not found to be a benefit in the studies done?
    And to end, may I just add my voice to the chorus thanking you for such an interesting and provocative article and an overall interesting blog.
    Hi Valerie–
    Thanks for the kind words about the blog. MD and I tried the IF for a while just to see if it were truly a practical regimen that could be followed easily. We found that it indeed is. We didn’t really go off of it completely. We only eat a couple of times per day most days and often go for long stretches where we don’t eat at all. We found that worked better for us than setting a more strict regimen.
    As to the life extension qualities of IF, I think I mentioned that in the blog, but didn’t really stress it. Thanks for bringing it up. One of the main advantages of IF is that it provides the same longevity benefits as CR, but without the caloric restriction. The animals that were on the IF regimen ended up eating as much as the animals that were fed ad lib (they ate twice as much on feeding days to make up for not eating on fasting days), but lived as long as the animals on 30-40% caloric restriction.
    Hope this helps.

  80. Well Doctor, I am on day four of my IFing! So far, down a pound and $5 richer.
    This is almost fun.
    Hi Lyndsey–
    Thanks for the report. I guess that’s another benefit of the IF: it’s light on the pocketbook.

  81. What were the other eat-fast-eat regiments that you played around with?
    Hi imsovain–
    Basically just fooling around with the cutoff times. We tried it at noon and mid afternoon and later in the evening. For us the 6 PM cutoff worked best.

  82. Dr. Eades,
    Above someone asked about the 15 hour fast recommended by De Vany and you replied you hadn’t seen any studies on it. Here’s a reference for you on Ramadan fasting. They study participants lowered their homocysteine levels on a 15 hour fast. The abstract says they fasted for 12 hours but if you read the actual study it says they fasted for an average of 15.
    Aksungar FB, Eren A, Ure S,T eskin O, Ates G. Effects of intermittent fasting on serum lipid levels, coagulation status and plasma homocysteine levels. Ann Nutr Metab. 2005 Mar-Apr;49(2):77-82.

  83. I started with only eating breakfast and lunch on Sep. 14 as soon as I finished reading your blog. So far I have to say it is not really easy but quite possible. I have now finished my 5th day with only breakfast and lunch again (tomorrow it will be dinner only and of course a snack at bedtime). I am still waiting to see if I have benefits. I only weigh 128 pounds so if I do lose it will be slowly, I’m sure. I would like to lose the 8 pounds that have crept on in the last year and a half. I have been low carbing for years and I do not lose on low carb if I don’t restrict calories as well but I find it impossible to restrict calories when I don’t low carb. I bought your “Protein Power” book as soon as it came out (and loved it) I also have “Thin So Fast” and I want to thank you for writing them and for all the research you put into them. I would love to have more information on Intermittent Fasting if you find any.
    Thank you Ruth
    Hi Ruth–
    Thanks for the kind words about the books. I’ll be interested to see how you do if you continue on with the IF regimen.

  84. I started with only eating breakfast and lunch on Sep. 14 as soon as I finished reading your blog. So far I have to say it is not really easy but quite possible. I have now finished my 5th day with only breakfast and lunch again (tomorrow it will be dinner only and of course a snack at bedtime). I am still waiting to see if I have benefits. I only weigh 128 pounds so if I do lose it will be slowly, I’m sure. I would like to lose the 8 pounds that have crept on in the last year and a half. I have been low carbing for years and I do not lose on low carb if I don’t restrict calories as well but I find it impossible to restrict calories when I don’t low carb. I bought your “Protein Power” book as soon as it came out (and loved it) I also have “Thin So Fast” and I want to thank you for writing them and for all the research you put into them. I would love to have more information on Intermittent Fasting if you find any.
    Thank you Ruth
    Hi Ruth–
    Thanks for the kind words about the books. I’ll be interested to see how you do if you continue on with the IF regimen.

  85. I think I still have the same question regarding, or rather comparing a well followed protein-adequate/carbohydrate-controlled approach like Protein Power with an intermittent fast. Since my definition of life extension is a little different, I only look at the benefits and quite frankly, I don’t find IF superior than say Protein Power. Even compared to plain caloric restriction, carbohydrate control (as you wrote it once), is perhaps the most clever way to reduce calories for those who still buy into the standard calorie rule.
    Don’t get me wrong, I don’t argue the reported benefits attributed to IF, but so far, and this is just a personal comment before I get jumped at, I don’t see the need of dealing with the practicalities of having to set a particular time to eat (which may or not fit into my life, which tends to be full of unexpected events), plus dealing with the apparent constant thought of how much I’m going to enjoy f’east-day’. Of course we get used to almost everything, even to not eating or not sleeping enough, and I wonder how much of that is true effect of IF and how much comes from our minds shutting down feelings of hunger as a coping mechanism. Anecdotically, even before I heard of Protein Power, I ‘got used to’ not eating breakfast and I didn’t feel hungry at all until lunch time, but that didn’t mean it was doing me any good. Anyway, just pondering ideas here. I suppose the message I take is that if the circumstances so demand it, at least I know that there is benefit in a little fasting but only if the circumstances so demand it.
    This fascinating topic has generated a lot of posts on the Protein Power board, which is good. However, there seems to be a bit of confusion with “what is the way to go now… Dr. Mike now says we need to fast to get better health… whatever happened to Protein Power then?” [that’s the current perception from some of the participants]
    To me it’s still clear Mike, but would you mind clarifying your position just a tad for those who are new to Protein Power but are now wondering what exactly is your advice regarding a comprehensive, sustainable and beneficial nutritional plan? Thanks a lot in advance.
    Hi Gabe–
    Thanks for all you help with the board and your concern. See today’s post. I hope I’ve clarified things somewhat.

  86. Hi, Mike…I thought you might be interested in how this discussion is progressing in one thread in your own forums.
    Several posters have questions/concerns about the impact of IF on hypoglycemia and on reinforcing binge behavior and/or emotionally-motivated eating. Any comments?
    Hi Gaelen–
    I wouldn’t think there would be much of an impact on hypoglycemia for anyone not on diabetic medicines. I don’t have any info or data on IF and binge or emotionally-motivated eating. Maybe today’s post will clear up a few other issues.

  87. Sir what do you know about cancer cells and them not being good (or unable ?) at using ketones to increase the size of the tumours ? Any comments ?
    BTW Robb Wolf is a real decent ‘uman being
    Hi Simon–
    I know that cancer cells can’t use ketones for energy and must turn to glucose to grow and reproduce. Which, in my opinion, makes it almost criminal to put patients with cancer on low-fat, high-carbohydrate diets.

  88. Dr. Eades,
    All of the papers that I’m able to find concern intermittent fasting by adults. What is your opinion on the health effects for children and teenagers?
    David Sears
    Hi David–
    I have no opinion because 1)I’ve never tried it on children; and 2) like you I haven’t read any papers on it.

  89. Dear Dr. Mike,
    I’ve been on IF for 48 hours now and I’m gonna be honest with you–I HATE IT! 🙂
    While I knew I would be quite hungry after my first fast day, when 6:00PM rolled around I felt like I couldn’t stop eating. In fact, I ate four times in that first hour and I was STILL hungry.
    And in Day 2, something really strange happened to me when I went to workout. Despite the fact that I could eat during the daytime, I had to back off on both the intensity and resistance of the elliptical machine I use because I didn’t have the energy to exercise as I have daily for the past three years.
    While I can certainly appreciate what IF is supposed to do to help people reduce their caloric intake, I couldn’t see myself doing this again after this first week unless it gets a whole lot better in the next day or so.
    But, I’m not a quitter and since I committed to doing it for at least a week, I will see it through to the end. Please make the pain go away! 😀
    Jimmy Moore, author of “Livin’ La Vida Low-Carb”
    Hi Jimmy–
    Thanks for the update. Keep me posted.

    1. Be careful you are drinking plenty of water. When we don’t eat we often don’t have much desire to drink, but we need to. Have a little salt with it. I found when I tried to exercise my first day doing this I couldn’t because I was dehydrated. When I drink water, I can exercise.

  90. Dr Mike
    Okay, a few questions off the top of my head:
    Why am I getting sleepy on my fast day when I’ve had no carbs?
    Are rashes supposed to get worse before they get better? Both my shins are worse than last Thursday when I started.
    How soon should I expect to have my ankles stop swelling at the end of the day?
    Any info or speculation on what is happening would be appreciated.
    Hi LC–
    See today’s post.

  91. Hi, Dr. E. –
    Stumbled upon your blog and found it fascinating.
    I’m wondering if you have suggestions for adapting IF for children.
    My son is ten, overweight by about 30 pounds, and I fear he will become diabetic. (His birthmother was obese and diabetic at a young age.)
    He’s quite active, has an excellent lower-carb diet and doesn’t eat massive quantities of food. He’s homeschooled, so I prepare all his meals and snacks. Yet he gains weight at the drop of a hat.
    His bio half-brother, whom we also adopted, eats almost exactly the same stuff and same amounts and is skinny as rail.
    He has been checked out by endocrinologists and so on and no physical cause for his weight issues have been identified. The doctors just say, “make him eat less.”
    As you can imagine, it is not easy to put a child on a calorie-restricted diet, for a variety of reasons.
    He constantly claims he is “starving,” and this is on a regular diet!
    Even if it were appropriate (and in his case I do believe a somewhat aggressive approach is justified), he could never handle even the modified IF schedule you propose.
    I am wondering, though, if you think there would be any benefit to trying the schedule used in the study you cited—50% on one day, 144% on the next.
    Then, I’m wondering if there are any suggestions on how one might “disguise” the 50% day. First, I’m thinking, of course, with activities and other distractions. But as for the meals—what is your view of diet sodas, loading meals with low-calorie foods so as to meet the 50% goal, etc.?
    Any help you can give would be very appreciated.
    Hi Nellie–
    I understand your frustration. I’ve had no experience with children on the IF, so I can’t really make a recommendation. I would recommend, however, that you maybe get your son reevaluated by another endocrinologist, maybe one more attuned to weight issues.
    Good luck.

  92. Sir thankee. ye know the work of Nick Gonzalez MD ?
    He trained at SLoan Kettering and then met the somewhat infamous Dr Kelly.
    He has some very impressive stats with remission for stage 4 cancer i think partic pancreatic
    He ‘prescribes’ a strict paleotype diet for some patients and then strictly veggie diet for others based on a whole slew of variables….some of which seems floored and incredibly so.
    I’ll give it a look. Thanks.

  93. David Hola…my two penneth.
    I would wager it would be deadly good for kiddlies given they lived in the same enviro as adults ( really i sometimes think i have shite for brains !) in evol.
    I mean look at what the keto diet does for epileptic kiddlies

  94. Doc
    I’m a Insulin dependant type 2 diabetic RN…yep…I knew better.
    I’ve been able to cut my insulin in 1/2 by controlling carbs, adding in exercise every day and now doing the IF.
    It’s fastings are lower…I feel pretty good. I love the feeling of freedom from always thinking about food and with less injected insulin I’m getting away from the “feed the insulin” feeling that it can cause.
    My question is more on timing. I have been limiting myself to one meal a day….timing depends on schedule and one snack as a meal a day….something like a low carb soup. What I am enjoying is the anticipation of my meal and the fun in preparing it and the feeling of being satisfied after that meal. Is the timing the main criteria? I’ll be less scheduled when I get off insulin completely but to do that more weight loss has to occur. Once that occurs then I can be more flexible.
    Thanks for the great blog.
    Hi Ressy–
    Thanks for the great story. Hang in there and keep up the good work. It will pay of big time.

  95. Mike…My friend who was an avid LC’er along with me has been going to a trainer at a gym. He has him eating 5 large chicken and veggie meals a day (no fat) and told him if he didn’t eat 5 meals a day his metabolism would die and he would not build muscle. I have heard that if you skip a meal esp breakfast that it will hurt your metabolism and it scares me as even though I have strictly followed a LC diet for 4 years (I am very educated in LC I had two brick and morter LC stores and now have a website since I had to close my stores) I still have 25 stubborn lbs to lose. I know Dr. Atkins said do not eat unless you are hungry even breakfast. I am never every hungry in the morn or really most of the day. My husband and I wish actually they had a pill you could take and just skip food altogether lol. I would like to try this but again will it kill my metabolism? I’m sorry I can not remember his name but the guy who started “Curves” wrote a book and had an interesting fasting concept in it. This is off of the subject but I wish you would do some research into bio identical hormones and thyroid and how the problems leading up to needing these meds affect an older women’s weight and how LC can fight into her life. I would bet you would sell a ton of books on the subject esp since all of the women in the WHI flow fat study were post meno..
    Hi Linda–
    The portion of metabolism affected by diet is relatively small. The main part of your metabolic rate is set by your weight. Based on the studies I’ve read, I don’t think the IF is going to do much of anything to your metabolic rate: it certainly won’t ‘die.’
    Keep me posted on your progress.

  96. Does coffee with cream only count on the IF and diet soda count?
    Hi Claudia–
    I’m not sure I understand your question exactly. If you mean is it okay to have cream with your coffee on the IF, my wife would say, go for it.

  97. Thanks again for covering this topic on your blog. You have been quite generous with your time in responding to everyone’s comments and questions!
    You asked for us to let you know how IF is going for us.
    Since you indicated there isn’t enough research to determine the “magic” number of hours or perfect schedule, I selected what would work for me long term. I’m eating between 5 and 10 p.m. every day, fasting the rest of the time.
    Here’s my experience so far, after doing my version of IF for 5 days (today is the 6th). (I’m eating how I normally do when I’m being “good” about carbs — somewhere between 50 and 100 g per day. I have been convinced since way before you published PP that LC is the way to go, since I’ve struggled with reactive hypoglycemia for many years. I am even more convinced about LC/adequate protein since reading your books.)
    The main benefit of this IF experiment for me so far is the fact that this way of eating fits in with what has always just “felt right” to me. The freedom from being required to follow rules of eating “three squares at 7 a.m., noon, and 6 p.m., plus snacks” is worth the price of admission for me. (I’m delighted that there is evidence that I’m not harming myself eating the way I prefer.)
    Other benefits of note so far:
    I feel fantastic physically. No energy drops during the day. Noticeably improved endurance when working out. I’m working out 1 to 3 hours prior to my first meal, so approximately 15 hours after last eating. (I’d estimate at least a 50% improvement in endurance here; subjective, I know.)
    I feel great mentally/emotionally — good mental energy and focus, even keel with emotions.
    I had taken measurements a couple of days before starting the IF. I took them again yesterday — 5 days after changing to this way of eating. I have lost 5 inches spread out over 5 measurements on the torso (chest, bust, under bust, waist, and hips). In the same period of time I have gained half a pound (which I take to mean I basically weigh the same).
    I had blood lipids measured a couple of weeks ago (I tend to have higher numbers than I’d like.) I have an appointment to have those checked again next month some time. I plan on staying with the IF until after my next blood tests and doctor’s appointment in October. I’m also tracking my blood pressure (just one reading a day), so I’ll be able to see if there is any trend there.
    Certainly not statistically significant with a sample size of 1 and no control, but enough good stuff happening here to keep me interested and motivated to continue for a while.
    Hi Peggyjo–
    Thank you very much for taking the time to give such a complete update. It’s interesting that you seem to have more endurance while others report less.
    Please keep me posted as you go along, especially about the blood tests.
    Thanks again.

  98. Today is one week on the program, and I have neither gained or lost any weight at all (128 pounds) but my waist measurement at the naval has gone up nearly 1 3/4 inches. I am afraid that may mean excess cortisol production from stress and since the only stress I can think of is from the IF diet I do wonder about it. Do you have any suggestions of any thing else it could be? Other than that I feel OK and am not finding it too hard. I certainly look forward to dinner after skipping three meals, and it it does taste good.
    Hi Ruth–
    I doubt that your increase in abdominal girth is from excess cortisol. It just doesn’t work that quickly. Without a detailed history I would be hesitant to make a diagnosis over the Internet. One thing to consider would be fluid retention as a function of carb intake. If you have previously been on a strict low-carb diet then started an IF with a lot of carbs, you could have a short term fluid retention that could both increase your abdominal circumference and mask a real weight loss.
    Keep me posted.

  99. Today is one week on the program, and I have neither gained or lost any weight at all (128 pounds) but my waist measurement at the naval has gone up nearly 1 3/4 inches. I am afraid that may mean excess cortisol production from stress and since the only stress I can think of is from the IF diet I do wonder about it. Do you have any suggestions of any thing else it could be? Other than that I feel OK and am not finding it too hard. I certainly look forward to dinner after skipping three meals, and it it does taste good.
    Hi Ruth–
    I doubt that your increase in abdominal girth is from excess cortisol. It just doesn’t work that quickly. Without a detailed history I would be hesitant to make a diagnosis over the Internet. One thing to consider would be fluid retention as a function of carb intake. If you have previously been on a strict low-carb diet then started an IF with a lot of carbs, you could have a short term fluid retention that could both increase your abdominal circumference and mask a real weight loss.
    Keep me posted.

  100. I made it through my 3rd fasting day. My fasting blood sugar dropped from 98 to 85 within 2 days and I lost 3 pounds. I felt very strong on my weight training and bike ride even on and empty stomach at the end of the fast. I got a burst of energy. I’m going off the 24hr on off and do will it more sporadically for a while. My brain tingled. Must be new nerve cells getting created. One downside, is that I did eat a little too much too fast when breaking the fast.
    Hi Joyce–
    Thanks for the update. When you’re first getting started, it’s easy to eat a little too fast. I was face down in my first plateful when I did it.

  101. Hi Dr. Mike! I decided to check in at the end of the week. I was waiting for Dr MD to weigh in on IF, guess she saw the monster you created and decided to steer clear. I lost 2 3/4 lbs and most likely would have lost more but fell prey to a jar of peanut butter. I know better than to buy it but every time I tell myself I can control this obsession I have, Oh well it is gone now,( The peanut butter, not the obsession with it) but I digress. I felt perfectly normal.I walked 2 miles twice a day(3 mph) and worked out at Curves 3 times. I always have worked out on an empty stomach because I read somewhere you then burn the fat that is stored rather than using the energy you just ingested, or something to that effect. I have a problem with hunger tho. If I waited to eat until my tummy said eat It could be days.I know at no time did I truly feel hungry not even after the 24 hour fast. I learned a lot about food too. I have always eaten several small meals. Like the gorilla I eat all the time. It was all I ever heard, The AOE is most likely responsible for that, I felt a great deal of freedom not having to think about food and saved a bunch of money. I think I will give the IF another week. This is the most I have lost in 1 week in over 2 years. Once I got most of the weight off I seemed to quit losing, or slowed to near stop, 1 lb a month is as near a stop as I can tell. Sorry about the length of this, I write like I talk, fast and alot.Wishing good heath to the First family of Eadsville!
    Hi Tess–
    Thanks for the good wishes! We here in Eadesville take them wherever we can get them.
    And thanks for the update. Keep us all posted as you continue.
    Good luck.

  102. How about fasting during the week and eating during the weekend? I’ve done that before with considerable success.
    Hi Brent–
    If it has worked before, go for it. As I’ve said in reply to a number of other comments, at this stage I don’t think anyone knows the optimal length of fasting. In the early part of this century Bernarr McFadden, a famous health buff, would fast for days at a time. It didn’t seem to do him any harm.

  103. Great article, very inspirational! I’ve been eating two meals a day – breakfast and dinner – for a while now, I’ve also low-carbed all the way through. It works.
    But now this has me very excited – if I eat only once a day, can I really, REALLY eat as much as I want? If so, I’ll switch in a heartbeat. Even with only two meals a day, I find I’m having to stop before I really want to. I just like food too much. Eating to the point of real satisfaction would be such luxury, yet has always seemed so unattainable… so… NO restriction if I only eat once a day (low-carb, of course)??
    Hi Sunny–
    That’s what the studies seem to show. Go for it and see what happens.

  104. Thank you so much for your prompt reply. It must be water retention, but I am still low carbing. Not as low as induction but low. I have not kept strict numbers on calories or carbs since starting this thinking it was unnecessary, but maybe I had better. I am still waiting for relief from allergy symptoms and hoping desperately for memory improvement, and longevity if possible. I’m 72. I have kept up my exercises. Free weights twice a week and walking on treadmill two days out of three.
    Hi Ruth–
    Thanks for the update. Keep me posted.

  105. Thank you so much for your prompt reply. It must be water retention, but I am still low carbing. Not as low as induction but low. I have not kept strict numbers on calories or carbs since starting this thinking it was unnecessary, but maybe I had better. I am still waiting for relief from allergy symptoms and hoping desperately for memory improvement, and longevity if possible. I’m 72. I have kept up my exercises. Free weights twice a week and walking on treadmill two days out of three.
    Hi Ruth–
    Thanks for the update. Keep me posted.

  106. I realize this isn’t a diet per se but I was wondering if it is possible to lose weight with the 24 on 24 off fasting plan? Or does it put your body into survival mode and not let it lose any fat or weight? I have only been trying this for a few days but it is fairly easy to stick to and if I reap the other benefits then it is well worth it. But I would like to lose 5 or so pounds and am hoping this would help me do that. Thanks.
    Hi Misty–
    A lot depends on how much you eat during the ‘eat’ days. If you eat double what you would normally eat, you probably won’t lost much. The lab animals that did the IF and ate double on eat days got all the health and longevity benefits that the animals did on caloric restriction, but they didn’t lose a lot of weight. If you eat about what you normally eat or even a little more when you’re non-fasting on your ‘eat’ day, you should lose weight.
    Keep me posted.

  107. Ok, I used to do this about 25 years ago. I was very overweight and wanted to diet but it was easier for me to eschew food completely for the day rather than have small portions. I fasted on Mon, Wed & Fridays every week and allowed myself anything I wanted on the other 4 days. I don’t have any bloodwork from then, but I did lose a lot of weight and after a bit I actually enjoyed the fasting. Once I went for 3 days without eating just for yuks and it was totally fine with me.
    BUT! The late Dr. Atkins claimed that you had to stoke your metabolic furnace every 3 hours with some sort of snack even if you weren’t hungry. His opinion has prevented me from skipping meals. The idea being to keep your blood sugar on an even keel and not spiky.
    Would welcome your comments. Thanks
    Hi Laurel–
    The idea that you have to keep your metabolic furnace stoked is a myth. Look back over the last few comments as I discussed more fully what happens to blood sugar during a fast and how the metabolic rate is set.

  108. Thanks for the post, Dr Eades, and thanks for answering so many emails. If you have stopped doing so before getting to this my feelings won’t be hurt, but in case you still are, I have a question about water weight. I started IF (after the pattern you suggested) on Monday–didn’t weigh until Tuesday morning. Since then I’m down about three pounds, which is surprising, since I’m certain that in my case this has resulted in a great decrease in calories. (Also in a significant decrease in carbs, although I was going from low-carb TO low-carb.) Normally I would expect a larger initial weight loss from such a change (due to water loss), and was curious to know if the body might react differently to caloric/carb reductions with THIS pattern of eating as opposed to similar reductions with “regular” eating. (By the way, I had a murderous problem with late night binging, even on low carb–it was as if a false bottom dropped out of stomach between 8 and 10 PM–and that problem is instant history.)
    Hi Michael–
    If you had been on a low-carb diet previously for any length of time, then I would imagine that your insulin sensitivity had already improved. It’s the almost immediate increase in insulin sensitivity when switching to a low-carb diet from a high-carb diet that causes the water loss. A switch from a low-carb to a little lower probably won’t make the same difference.
    I’m glad you’ve conquered the late night binge demon.

  109. Dr. Mike,
    I’ve read your article, and some of the posts following the article. I’m thinking of giving this a try, with a (hopefully) minor variation. Here’s the schedule I came up with:
    Weekly schedule:
    Saturday: LC lifestyle, eat 3 LC meals
    Sunday: IF lifestyle, no food after 8 pm (eat Bfast, Lunch, Dinner before 8pm)
    Monday: IF lifestyle, no food before 6 pm (eat Dinner after 6pm)
    Tuesday: IF lifestyle, no food after 8 pm (eat Bfast, Lunch, Dinner)
    Wednesday: IF lifestyle, no food before 6 pm (eat Dinner)
    Thursday: IF lifestyle, no food after 8 pm (eat Bfast, Lunch, Dinner)
    Friday: IF lifestyle, no food before 6 pm (eat Dinner)
    The reason the “no food” IF days end at 6 pm instead of 8 pm is to allow a family dinner with the little one before her bedtime. Basically, this schedule allows our family to maintain a 6 to 6:30 “dinner time” every day. And by making Saturday a LC day I don’t disrupt the families meals then either (we’re already used to me eating LC while other family members have whatever). I also like this because my IFing fast days are all work days (M, W, F) when I’ll be mentally engaged in other activities and therefore (maybe?) not so focused on the fact that I’m not eating.
    I’m going to start this tomorrow (Saturday), and I’d appreciate any comments, guidance, or good jokes you may have.
    And a couple of specific question:
    1) What would you say to a glass of wine during my “no food” evenings? I’ve found I can sip on a single glass for several hours in the evening.
    2) What about chai tea made with either cream or 1% milk? Same thing in that I can sip on a large mug of hot chai for several hours. (Sweetened with Stevia).
    Both seem to eliminate my evening snacking problem quite effectively.
    Thanks and regards,
    Hi Dan–
    Since there are no rigidly set rules, you can pretty much set it up however works best with your lifestyle. The important thing is to have a single, long period of time without food intake. I don’t know how the wine or Chai would fit in. The best thing to do it try it both ways and let us all know how it works for you.
    Good luck–

  110. This came from Dr. Hymans’s “Ultrametabolism” Book. It is the oposite of what you are stating and what we hear most of the time. Although when I eat breakfast it is like opening the flood gates and I am starving all day lone. Linda
    It’s Dr. Hyman again with your next installment of the mini-
    course titled:
    “How To Reset Your Metabolism to Lose The Weight and Keep It
    Off For Life”
    Today, I’ll explain how sumo wrestlers gain so much
    weight… And I’ll show you why you may be on the VERY SAME
    diet that sumo wrestlers use to gain hundreds of pounds!
    And of course, most importantly, what you can do to stop
    eating like a sumo wrestler and start eating what your body
    was designed to eat.
    ==> The Sumo Wrestler Myth
    Have you ever wondered how sumo wrestlers gain so much
    To understand how they do it, you need to first understand
    how they live: They skip breakfast, exercise for about 5
    hours, eat a huge meal, and then take a long nap.
    What’s wrong with this picture?
    Nothing, if you’re a sumo wrestler.
    The problem is, you’re not, but you might be living like
    The typical routine of most Americans is startlingly similar
    to that of a sumo wrestler: they skip breakfast, work all
    day, come home to fill up on a big meal, and hit the sack
    soon after.
    No wonder so many Americans are overweight or obese!
    There are two key behaviors in this routine that ensure that
    you’ll gain weight, just like the Sumos:
    1. When you skip breakfast, your body automatically goes
    into starvation mode (which I explained in an earlier
    lesson). This makes your body store as much fat as
    possible, instead of burning it. And it also keeps you
    hungry, so you gorge on as much food as possible later in
    the day. That adds up to more food than you would have eaten
    if you had 3 or 4 smaller meals.
    2. You eat too close to bedtime. Eating right before you
    sleep practically guarantees that you’ll gain weight because
    when you go to sleep with food still in your stomach, your
    body automatically stores the food as fat and burns less of
    What’s the message here? Don’t eat within 3 hours of your
    Here are other tips for avoiding sumo-size weight gain:
    – Eat breakfast. Make hearty, healthy breakfasts a habit.
    Filling up early helps keep your appetite in check all day
    long and revs up your resting metabolic rate, so you burn
    fat all day long.
    – Eat 3 or 4 more times during the day. Eating small,
    healthy meals more frequently continues to keep your
    appetite under control, and gives you the energy you need to
    motor through your day.
    – Avoid eating within a few hours before bedtime. Leaving
    time for your body to digest ensures that the food you eat
    will be burned rather than stored as fat.
    (You’ll find more details on the Sumo Wrestler Myth in
    Chapter 5 of UltraMetabolism.)
    Following this advice but still overweight?
    It could be your thyroid.
    ==> Fortify Your Thyroid: Maximizing the Major Metabolism
    Hi Linda–
    Dr. Hyman needs to do a little more research on the Sumo wrestlers before he makes the ignorant pronouncements that he does.
    Here is a link to the PDF of an American Journal of Clinical Nutrition article written by Japanese researchers on the diet of Sumo wrestlers.
    If you read it you will find the the class of Sumo wrestlers in training for the big time eat over 5000 kcal per day composed of over 1000 grams of carbohydrate and only 50 grams of fat. These wrestlers eat huge high-carb meals twice per day. Doesn’t look like much of an IF to me.

  111. Thank you SO much for the sumo wrestler info. Just logically, they can’t be eating just a regular Japanese diet crammed into a few hours at night!!
    Very limited try at IF – one B/L the day after ‘restarting’ PP/LC. More energy, less $/time spent on food, lower resting BP & P this am. Joining the IF conversations on the bulletin boards. Planning a 3day/wk IF pattern.
    Beginning as I intend to continue. 🙂
    Hi Nean–
    Good luck on your IF. Keep us posted.

  112. I have fiddled with the low carb idea (and practice) since the early sixties when chance led me to a book presentation in London by Dr. Richard Mackarness. It opened my eyes and I have rarely strayed from the basic premise of Banting’s regimen (Eat Fat, Grow Slim)
    Having been educated in the Fatherland, I was also exposed to various natural “cures” such as fasting. So, it came quite naturally that I would experiment with the two in tandem.
    I plan to do a strict one day fasting, next day low carb eating for 12 weeks just to see what it will do and lose the few pounds that I recently put on as a result of a major stress (no, not illness).I also run long distance including marathons (all on bare feet, incidentally) and do fine with the very low carb intake.
    I have no results as yet but will let you know if anyone is interested.
    Best to all,
    Hi Dr. Nehrlich–
    Thanks for commenting. I’m looking forward to hearing from you as your IF progresses.

  113. Hi Dr. Mike,
    I’ve been practicing IF for six weeks, after a friend on my master’s swim team mentioned he’d been doing it for three years (he’d read about the rat study and just decided to try it to prevent his aging bio-markers from going up). I fast every other day, for a total of 36 hours. So far, I’ve lost 11 pounds and my BMI is 22. The hardest part for me is going to bed hungry so I sometimes break the fast a little before bed by eating a handful of raw almonds or a bit of cheese or half of an avocado, something low carb of approx. 250 calories. This helps me sleep; otherwise, I toss and turn. I exercise 6 mornings a week (4 days of 90-min. swimming and 2 days of 90-min weights) and have found no difference in performance, though sometimes I feel a bit weaker on the morning after a fasting day (I do eat before working out but it takes a while for the food to give me some energy, I can actually feel it kicking in about half way through a workout).
    I have really enjoyed the self-knowledge I’ve gained from going without food several days a week. I have learned how I use food to cope with stress and emotions. I’ve learned what hunger really feels like and how to delay gratification and it’s been eye-opening to find out how much time I spend planning meals, preparing them, eating them, etc… On my fasting days, I have so much more time. It has been a powerful series of lessons; in fact, empowered is a great way to describe how I view myself now.
    There have been physical benefits, as well. In addition to losing the weight (I’d like to lose about 8 more pounds), on my fasting days I often, but not always, have increased mental clarity and well-being. I feel less anxious, more centered, calmer and much more detail-oriented. My focus is greatly improved in the late afternoon. I also immediately noticed after starting this eating plan that I had improved sensory perceptions, including a greatly increased sense of smell and hearing. Colors also look brighter and more vivid, though, alas, I still need my contact lenses. I find myself completely turned off by television; something about the flashing, flickering screen and the noise is now unappealing. My skin has a healthy glow and it sometimes feels on fasting days like I have a slight fever, as if my body were cleaning house. These feelings carry over to my eating days. I’ve never been on anti-depression drugs or Attention Deficit medication, but it really almost feels almost like combination of what those two drugs would do.
    Anyway, thanks for your information. It’s been interesting reading people’s responses. I will probably continue the 36-hour fasting until I hit my goal weight and then switch to 24-hour fasting every other day (eating dinner every night).
    Hi Melissa–
    Thanks for an insightful comment. I really appreciate (as I’m sure the other readers will as well) your history and your subjective feelings.
    Keep us all posted.

  114. I started this later than some, last weekend, and am easing in gently with the “wimpy” approach Laub et al described: 20-50% cals one day (eating one, two or three times, depending on my day), ad lib the other. So far I’ve felt pretty hungry on the low cal days, but not impossibly so. I suspect I’m not quite eating enough to compensate on the ad lib days – but it’s been less than a week so although my weight is down a tad, it’s too soon to say if that’s real. I don’t want to lose weight (I’m about 22% BF and quite happy there), so I’d like to keep the cals up. It feels as if my allergic rhinitis is slightly less on the low cal days, but not on the ad lib ones so far.
    Hi Janet–
    Thanks for the update. Keep us posted.
    Good luck–

  115. Well, here are the results!!! I’ve been back on strict low carb for 3 weeks now. The third week I fasted 1 day and broke the fast with pizza! LOL I figured it was a good thing to try because I’ve been craving pizza!
    Well…..I lost 4 pounds this week!!! I’m amazed since I’m one of those that loses well at first, then the loss slows to a crawl.
    Definitely going to try at least 1 day a week….but not break the fast with pizza!!! I was miserable all night!
    Hi Cindy–
    I’m happy to learn of your success. Keep it up and keep us posted.

  116. What about IF for someone who will be trying to get pregnant or even newly pregnant? I will be trying to get pregnant with my next cycle, and would also like to give the IF a try. What do you think?
    Hi Michelle–
    I have seen no data on the IF used in pregnant women. I wouldn’t think it would be a problem while you’re trying, but once you are pregnant, just to be safe, you should follow your normal diet or whatever diet your Ob/gyn recommends.

  117. Count me in as one trying this approach with a slight modification. I’m eating a full meal at or before 6 pm on my non-fasting days. That may change soon depending on my results, but so far, I’ve dropped from 202 lbs to 195, and I hadn’t been able to make the scale budge in several weeks previously.
    I just happened to stumble onto this because I was fasting out of frustration with my digestive problems last week. Once I read this article and some others like it, I broke my fast at 32 hours and went this direction. I’m experiencing reduced allergy and digestive problems using IF, and I’m not experiencing any major energy problems other than a desire to sleep earlier than normal on my fasting days.
    I’m keeping track of my progress on my own blog if anyone cares.
    Thanks for the information, Dr. Eades. It’s nice to see some alternate ideas on diet when I had been convinced 6 small meals a day was the only way.
    Hi Hap–
    Thanks for the informative post. I’m glad you’ve had such success; thanks for telling us about it.
    Keep us posted.

  118. I am a current lc’er and have been reading up on IF. I suffer from Dercum’s Disease and I’m looking for all I can do to improve my quality of life. I wonder if IF is an option for me.
    Hi Lisa–
    I have never treated a patient with Dercum’s disease, so have no experience as to whether a low-carb diet or an IF regimen would help. Since it is the fatty tissue that is painful in this disorder, it would seem to make sense to reduce the amount of such tissue. Also, I can’t imagine there not being an inflammatory component, and, since the IF (and the LC diet too, for that matter) reduce inflammation, it may help in that regard. If you do choose to try the IF, please let me know how it goes.

  119. I am a friend of Lisa’s and am learning about Dercum’s from her. Not yet dx’d myself, but expect to pursue a clinical dx as I compile my own history and seek advice on this matter.
    I am reading about Intermittent Fasting with some interest, as I recognize that my best days are always after a day of reduced food, for one reason or another. Invariably, less food means less pain, less edema. Always.
    Hi Zer–
    Thanks for the info. Keep us posted should you give the IF a try.

  120. Hi Dr. Eades,
    I was wondering if you have any information on IF and metabolism? I have always heard that eating 5 or so small meals a day would keep your metabolism high and that skipping meals would slow it down. I have never tried the 5 meals a day approach, actually my metabolism always seemed pretty good – I was able to eat basically what I wanted and if I needed to lose a little weight it wasn’t very hard until I turned 40 or thereabouts I noticed it wasn’t as easy to lose that extra weight. I started IF two weeks ago not really to lose weight but more for the health benefits that I have read about – but I was hoping to drop 5 or so pounds. I don’t think I am eating double the amount of calories on my eat days but I have not lost any weight – I have not gained any weight – just maintained. I am not overweight by standards that I have seen (5’3″, 114 pds.) but like everyone I have a particular image that I would like to obtain. I work out approx. 4 days a week and eat what I consider a healthy diet. Do people sometimes reach a certain weight and no matter what you do it won’t change? Anyway I was wondering if IF could be effecting my metabolism. Thanks in advance for your information. I very much enjoy reading this blog.
    Hi Misty–
    Metabolic rate is primarily a function of body weight. The contributions made by activity level and the thermic effect of food add to the total, but the largest component is determined by body weight alone. It makes no difference metabolically whether you eat many small meals or one large meal. What does make a difference is the composition of the meals. There are some interesting studies showing that, in women, at least, increased protein intake brought about significant weight loss. I don’t know what you’re eating when you eat, but you might want to crank up your protein intake a bit.

  121. Hi Michael,
    thank you very much for letting me translate your Intermitting Fasting article to our Finnish low carb forum.
    People have been very excited, and we have now 50 lowcarbers trying this for a month. A week has passed and this far only one has given up. We call IF Pätkäpaasto in Finnish, it is something like Fast Shorty in English.
    After a month, what kind of questions would you like me to ask in a questionnaire?
    Best wishes
    Hi Hoover–
    My pleasure. I’m glad your fellow LCers found it interesting. Let me think about the questions and I’ll get back to you.

  122. I’m experimenting with IF (by eating an early supper and then skipping breakfast, so I’m going 18 hours without eating). I find that when I do eat, I don’t eat more than usual to make up for my skipped breakfast. I’m also more aware of eating only when hungry. This is a big realization for me. I would eat because it was mealtime.
    It seems to me that if you do IF, you end up doing some CR also. when you do IF, do you end up eating the same number of calories overall? I don’t.
    When you become a 2nd Initiate in the religion I belong to, it is recommended that you fast on Fridays – a full fast, a partial fast or a mental fast. I was doing the mental fasts but decided to do a food fast. I was thinking of eating at 6 pm but wasn’t that hungry and I couldn’t decide what to eat so I decided to just skip supper and wait until the next morning to eat. I had difficulty sleeping that night. is this common?
    If one just eats 2 meals/day instead of 3 meals/day, without those 2 meals being larger than before, you’ve just cut your calories by one third. Seems like an easy way to do CR. Eating very LC (which I do) makes it easier to skip meals and/or to fast.
    Hi Carolyn–
    Unless one doubles up on caloric intake on eat days, one definitely does CR. No question about it.
    As I’ve mentioned before, I don’t think there is any magic number in terms of how long between eating, no one size fits all. But I do think that since the non-eating interval is what makes the thing work, it needs to be of significant length.

  123. Today starts my third week of IF. I’m doing it Warrior style so far, skipping BF and lunch. I have a two-hour eating window in the evening, and stick to relatively low carb eating. That gives me about 22 hours of fasting every day. I take one day off per week on the weekend, and eat lunch and dinner. (BF is never a good idea for me.)
    From day one, I have felt excellent! Lots of energy, clearer thinking, more focus, better stamina. A condition of numbness in my arms and hands has pretty much disappeared, and my neck, which has hurt for years, hurts much less and I can turn my head further.
    I love the freedom! Less planning, shopping, and preparing of food. Thus money, time, and effort savings. Also, I can go to work empty-handed, not packing food, and have my lunch break free to walk, read, knit, meditate, rest.
    I’m looking at IF as a permanent way of life. Can’t think of any reason not to stick with it indefinitely.
    Oh … and I’ve lost 7 lbs. in 2 weeks! I may just get to my goal weight yet!
    Thanks, Dr. E., for your blog here. BTW, at the top you mentioned writing more about the IF story in another post. Is that something you’ve done? And if so, where? Thanks again!
    Hi Jen–
    Thanks for the update on your version of the IF.
    I do intend to post on it again soon, but I don’t have a specific date in mind yet. Stay tuned.

  124. I’ve been practicing IF for about a month with good results — fasting BG is down about 10 pts. overall and the spikes are not as high. Thanks for the “push” to get going on this. Wanted to let you know about a great article in today’s Timesonline, if you haven’t seen it —,,8126-1707912_1,00.html It doesn’t name the WOE as IF, but that’s what it really is.
    Hi Brigit-Carol–
    Thanks for the heads up on the Timesonline article.  I’m a regular reader of Timesonline and somehow I had missed it.

  125. Dr. Eades,
    Have been doing IF for about a month now with good results, but have just found out that I have laryngeal edema, probably caused by laryngopharyngeal (acid) reflux. Several inconvenient things are supposed to be bad for this condition, including large meals, high protein, and high fat. (Although the ENT doctor I saw did not touch on any of those items.) Do you know of anything about IF research that would indicate that it MIGHT have any ADVANTAGES for this condition, and do you have any suggestions on what avenues I might go down to research it? (I’ve been prescribed Nexium, for which I subbed Prilosec on account of “poverty.” Many thanks again for your blog and for your many replies to all of us.
    Hi Michael–
    Take a look at this post on gastroesophageal reflux I wrote about a year ago. It should answer a lot of your questions.I
    don’t have any experience with patients on IF regimens and GERD, but I do have a ton of experience with patients on low-carb diets, which work like a charm.
    Keep me posted on your progress.

  126. Hi Michael,
    a group of Finnish low carbers have tested IF for a while. Do you have questions that you would like me to ask in a questionnaire?
    Best wishes
    Hi Hoover–
    Yes, please.  Ask how much weight was lost on average and when.  Did most people lose early on and then slow down as the IF progressed or did they lose about the same throughout or not much at first, then more later on?
    Also ask what were the main problems, if any, that people experienced.
    How long was the IF?
    Did people follow a low-carb diet on their eating days?
    Did people following the IF think (or know if) they ate fewer calories overall during the IF?
    How did people do the IF?  Fast every other day? Fast 6 PM until 6 PM the next day?  Did they eat anything at all on the fast days?
    I will be extremely curious to hear the answers.  Thanks for helping.

  127. Greetings Dr. Meades,
    I did alot of researching CR/IF over the summer by reading as much as I could on the web. The first of Sept ’06 I started my own version of the IF diet. On my fast day I allow myself all the fruit or vegetables (low glycemic) I want and keep my calorie intake below 500. I often don’t eat at all but, if I want, I will have steamed broccoli and a few apples if I need something. Even a soy burger patty or small glass of skim milk for protein. As long as my calorie intake stays at or below 500 I consider it a fast day. On my eat days I tend to still eat fairly lightly but will eat pretty much whatever I want. I also will allow myself dinners on Friday & Sat nites and fast during the daytime. My wife & I enjoy fine dining and often go out on the weekends. I just watch what I order and don’t overeat. I don’t try to make up for my fast day and I don’t allow myself to get stuffed. I’ve lost 17 pounds since I started (202 down to 185)and have an amazing amount of energy. I’m 46 and an ex-weightlifter (all natural, no drugs) so dieting is no stranger to me. I had to give up heavy-lifting due to some ulnar nerve damage. I ended up gaining weight and feeling lousy. Now I lift lighter and run 4 days a week along with the above diet and feel great. It’s the easiest diet plan I’ve ever done cos I eat whatever I want on my eat day…if I want cake, I’ll have a piece and it makes no difference. I think I’d have still lost a fair amount of weight even if I wasn’t running. Thanks for sharing your ideas – John
    Hi John–
    Thanks for sharing your experience.  Sounds like your version of the IF worked out great for you.
    Keep me posted as time goes on.

  128. I have been fasting one day a week for the past two years because I know it’s good for the body. And then I read about the intermittent fasting and started yesterday! I lost 3 lbs overnight drinking nothing but black coffee and water. (this surprised me as I am 5’1 and 119 lbs but would like to get back down to 107) I am going to continue doing this to see how it goes and my husband will be joining me in this journey as well. Will this fasting – mixed with eating days of low carb and weight training for an hour 3 x a week and doing cardio for an hour 3x a week – help get rid of excess skin by any chance?
    Hi Sheyla–
    Glad to hear of your rapid success on the IF.  Nothing like a little early positive feedback to keep one enthused.
    The best thing I found to get rid of excess skin is keep the protein intake up during the eating days.
    Keep me posted on your results.  Good luck.

  129. For those who are wondering about exercise and having energy while on a fasting day, let me tell you this:
    Today is my fasting day. I stopped eating at 4:45 last night – I don’t like to eat too late at night. So after going without food for 16 hours and drinking nothing but water and black coffee, I weight trained for an hour and I walked for 40 minutes (approx. 2 1/2 miles) with no problem and no energy crashes. Usually, weight training increaes my appetite. But this time there was no appetite. And I feel energized and rejuvenated after that workout! And this is with NO FOOD.
    On a side note, yesterday was my eating day. I ate approx. 75 g of carbs (which is high for me) and yet I maintained my 3 lb weight loss from Sunday into Monday.
    Wow. This is just amazing! I WISH I would have heard about this sooner. Thank God for low carb websites!
    Hi Sheyla–
    Fantastic results.  Keep it up.

  130. For the last year and a half, my wife and I have been encouraging people to try the “primitive” model of eating we call Fast-5 (A zero-calorie fast for 19 hours, then eat as desired for a 5 hour window, and one can go low-carb or not). I’ve used this model on-and-off since 1996 and given the growing obesity crisis, wanted to share it. We have seen impressive results, including anti-inflammatory effects, and hope that the increasing familiarity with IF will eventually overwhelm current custom and cultural pressure to eat 3x a day. The biggest obstacles to once-daily eating are the social pressure to eat and the deeply ingrained dogma about breakfast (aka “the breakfast myth”) that appears to be the result of successful marketing tactics. Since some people like a book to go with their diet, I wrote one, but it’s just as simple as you’ve said. One of the nicest changes is that money goes into the dieter’s pocket instead of some corporation’s.
    Whether one calls it Paleo, Warrior, Fast-5, or just “once-a-day,” the growing body of experience with it has to eventually overwhelm the uninformed “it can’t be healthy” mainstream opinion.
    It’s still a bit of mystery to me why some form of IF hasn’t shown up in big media outlets, such as on the “Biggest Loser” show. Even if it only spreads by word of mouth, it works so well for weight loss and weight maintenance, it will eventually be well-known.
    Hi Bert–
    Thanks for your input. It’s great to hear from folks who have been following such a lifestyle for some time, and who have put their own twist on it.  I’m glad it’s working for you.
    Let’s hope that the growing body of experience ultimately overwhelms the uninformed mainstream opinion, but I’m not holding my breath.

  131. Is it normal to lose appetite after doing this for awhile? I am finding that I am less and less hungry – on both eating and fasting days – as time goes by. I am making sure to keep my protein intake high on eating days.
    I used to be totally against fasting until I read the book ‘The Miracle of Fasting’ by Paul and Patricia Bragg. That really changed my whole opinion on fasting.
    Hi Sheyla–
    Yes, it is normal to reduce appetite after a while.  Make sure you keep your protein intake up on eating days.

  132. I started low carb 2.5 years ago in order to get my ravenous appetite under control and quit gaining weight (losing 60# has been a nice side benefit). I noticed recently that my appetite has again become an issue, although I only eat very low carb. I would force myself to eat within 30 min. of waking as I have read so many times suggested even though I was never particularly hungry, it seemed this would only stimulate my appetite and by evening I was on the constant prowl for food. I started not eating til 6pm and I have cut my daily quantity in half (or more) and I am no longer ravenous in the evening. I eat lots of eggs as a cheap easy protein source. Before I was eating 2 omelets a day, avocado/mayo/celery, ground flaxseed with 2 eggs & cream cheese, can of sardines and go to bed hungry; now I eat 1 omelet at 6pm & avocado/mayo/celery at 9pm and am satisfied. I have only been doing this for a week though.
    Hi Cindy–
    Sounds like you’re on the right track, but make sure you get plenty of protein.  Keep us posted.

  133. Is it okay to use with Splenda flavored packets in coffee while doing your 24 hours? I don’t do that often but every once in awhile, it just sounds good.
    Hi Sheyla–
    Since Splenda is non-caloric, it shouldn’t be a problem. Go for it.

  134. What is the recommendation for protein levels? I’ve been reading different things lately about the level of protein to take in. I assume I could find that info in Protein Power. Is there any change for those values based on eating significantly less food less often?
    Thanks in advance

  135. Actually, to clarify, my concern is too much protein. I’ve never had a concern about getting enough on a low carb diet. My concern is getting too much protein. I was reading a few articles yesterday that touched on Inuit societies and their largely fat-based diet
    A related article (that I can’t find now) warned against getting too much protein, and had suggestions for fat to protein ratios. It would be easier not to have to worry about too much. I can handle, “eat a lot of that”, but “eat some of that, then eat something else with more fat because there’s too much protein on that…” doesn’t work well with me.
    It shouldn’t be too hard, as I like fatty cuts of beef, for example. Just need to know if there is something to be concerned about, and if so, how much is too much.
    Hi Kevin–
    No, you don’t need to worry about too much protein as long as you have normal kidney function.  There are certain technical issues having to do with getting rid of urea, a product of protein metabolism, that supposedly sets the protein ceiling at 250 or so grams per day.  Many bodybuilders consume way more than that day after day with no ill effects.  The idea that we have to worry about getting too much protein is, in my opinion, a myth.  As long as we eat whole food diets containing plenty of good quality fats, there shouldn’t be a problem.
    Thanks for the link to the Discover article.  I hadn’t seen it.

  136. How many carbs do you recommend on eating days? And how many carbs or calories do you recommend when you break your 24 hour fast? And what do you recommend breaking the fast with-protein or vegetables? I’ve always been told to break it with something on the light side. Is this really a necessity? It seems I could get away with eating higher carbs on eating days if I am doing 24 on, 24 off -as long as it averages out to the right amount of carbs for me to be able to maintain my weight.
    Hi Australya–
    We’re not talking about a major fast here; we’re talking about 24 hours.  I don’t think it matters what you break it with.
    As to carbs and proteins, I don’t have any recommendations for them on the IF other than to get plenty of protein on eating days.  Plenty of protein is at least 0.6 gms per pound of body weight for someone with normal activity levels.  The reason I posted on the IF is that it is a method that permits more carb consumption yet provides many of the benefits of carb restriction.  Optimally, one would continue to restrict carbs to under 50 gms per day on eating days, but it’s not necessary to get plenty of benefit from the program.

  137. Forgive me if this ? was already asked and answered but I didn’t see it anywhere or I missed it.
    On fasting days, how many calories and carbs should you allow yourself when you break the fast? I know it shouldn’t be an all out feast, but is there a limit to how much so you don’t lose any of the benefits of the 24 hours of fasting?
    Hi Sheyla–
    There isn’t a limit.  That’s the point of the intermittent fast.  If you go without for one day, you can make up for it on the next.  It’s the long period of having no food that provides the health benefits.  If you want to maximize the good gained from the IF, I would recommend that on the eat days a low-carb diet be followed.  But don’t worry about the calories.

  138. I’ve done LC before but found this page on the ANA site. This seems like a great WOE as I’ve wanted to start fasting for some time now. A lot of the comments on here seem very doable. I want to know, do you have to have lots of veggies on your eat days or can you just have mostly protein? I like doing Atkins but I don’t seem to get up to the required amount of veggies. I don’t have a problem with the protein, though. Thanks for this wonderful site.
    Hi Charlene–
    Thanks for the kind words about the site.
    The virtue of the IF is that you don’t have to worry so much about what you eat on the eat days as long as you get plenty of protein.  If you like veggies, go for them; if it’s protein you like, have as much as you want.  It’s the day without that brings about the advantages of the IF program.

  139. I also advocate the Warrior Diet ideal, though I fully fast through the day, drinking coffee or water as wanted. And while Hokmekler(of the WD) did not advocate the low-carb approach, his diet does say to restrict the “bad” carbs, like flour(so he is pro quality carb and foods). But I write here today, because I wanted to say that in the diet book “The Carbohydrate Addicts Diet” by Rachael Heller, and her husband Richard, in Rachael’s introduction, she states she lost all her excess weight, over 100 lbs, by fasting all day, and eating what she wanted in the evening, as her dinner meal. This idea of daily fasting, is also supported by Dr. Mericle’s site, about the need to be in the glucagon state to lose weight, and how fasting is actually the increasing of metabolism. Interesting stuff.

  140. Dr. Eades,
    I’ve just finished my first 5 weeks on IF, doing a Warrior Diet-style approach where I eat every night in a 2-4-hour window, then fast until the following evening.
    I’ve lost pretty consistently, averaging about 1.5 lbs per week for a total of 7.5 lbs so far. After the first week where I was pretty ravenous by the time dinner came each night, I now have to work hard to get ENOUGH calories and protein (using nutrition-tracking software), since I’m satisfied with just a normal meal for dinner.
    Of course it’s nice not having to think about food during the day, or having to spend $7 or $8 or more on lunch out every day, and while the weight loss is nice as well, I was also losing when just following Protein Power normally (I still restrict my carbs and make sure I get my minimum protein according to PP every day while on IF). But what I’ve found is most striking is that my energy has increased tremendously. I would credit this somewhat to weight loss, but even after a couple of weeks and a couple of lbs, I had a lot more energy.
    In all, it’s been a great experience and I thank you for bringing it to my (and many other readers’) attention!
    Hi Levi–
    I’m glad the program has worked so well for you.  I noticed the same thing about the energy increase with the IF.
    Keep us all posted on your continued efforts.
    Cheers and Happy New Year.

  141. Dr Bert Herring has a similar IF plan, which calls for fasting all day till 5pm, much like the warrior diet. Check out the site, there is a free ebook that goes in great detail on how to setup and execute the fast-5 IF plan including the science behind it.
    Hi Fred–
    Thanks for the link.  It looks interesting.

  142. Dr. Eades,
    when I do an IF I find that I need a lot of coffee to get me through the fasting portion of things. Is this something to be worried about? My concern is the insulin resistance that comes along with chronic use of caffeine.
    When I break the fast I generally have a heavy resistancing training session and then have a meal of mixed pro/carbs/fat all whole foods and then I go back to low-carbs meals for the remaining eat phase till the 6pm fast. If I’m insulin resist from all the caffeine I’m wondering if the carbs port workout are going to be stored as fat versus filling up my muscles and aiding in my recovery from the heavy lifting.
    Finally your IF setup calls for eating till 6pm but most of the posters seem to discuss eating dinner/breakfast/lunch. I’ve been doing:
    [dinner|breakfast|lunch|small dinner just b4 6pm|fast till 6pm next day]
    this Ok from your point of view?
    Hi Fred–
    There is no evidence that I’m aware of that implicates coffee as a cause of insulin resistance.  In fact, the preponderance of the data seems to indicate that coffee is protective against diabetes, insulin resistance and all the rest of the so-called diseases of civilization.  I drink loads of it all the time, so if that’s what it takes to get you through the fasting days, I would say that the data says, go for it.  And don’t worry about it with resistance training.  Some studies have shown that coffee even improves that.

    Your regimen is fine.  There is no set regimen that I know of because people are just beginning to feel their way through this whole idea.  I would say that whatever works the best for you is probably the best.  
    Hope this helps.

  143. This article might be of interest to the fasters.
    We’re on Day 4 of our program, where we just skip breakfast and lunch every other day (KISS ). The second fast day was much easier than the first. I got a little sketchy around lunch, but was otherwise fine. We used the time that otherwise would have been spent on meals to hit the gym.
    I’ve noticed a couple of things, and will be curious to see if they continue. First and foremost, when we do eat, we eat a LOT less and feel stuffed. I’m probably eating 75% or less of what I would typically have for dinner, and today (which is an eating day) felt no urge to eat lunch. My wife reports that on fast days, she can have a very small snack (like a slice of salami) and get through till dinner with flying colors. After dinner on the fast days, I got a massive surge of energy.
    I’ve also lost 4 pounds, though I suspect that’s mostly holiday carb binge induced water weight.
    Hi Dave–
    Interesting article; I need to pull the paper from Cell Metabolism and look at it.  
    I’ve found the same thing when I IF.  I don’t eat nearly as much when I eat as I thought I would.  I’m ravenous going into my first meal after fasting, get started eating, then get full way before I thought I would.
    Keep me posted.

  144. IF is something I’ve been interested in for a while, and I’ve followed this blog discussion since it began. I should also say that PP and PPLP did a lot to convince me that the single most important thing that most of us can do for our health is to achieve insulin control. Carb restriction is the most intuitive way to achieve this, but it does seem that IF is a serious rival.
    As I see it, every diet involves some kind of restriction or, if you prefer, *change* from the eating habits that feel spontaneous to us, and which made us fat. Maintaining the restriction, whatever form it takes, requires a kind of mental vigilance. If it’s LC dieting, then one must be vigilant about carbs. IF requires vigilance about the *timing* of meals, rather than the amounts of food eaten or the ingredients.
    Long-term success depends upon what form of vigilance one can sustain. In this respect, IF has certain advantages. Mainly, there is this: There is (for me, anyway), a kind of psychological satisfaction that comes from having a meal that is *in no way* restricted, in terms of its actual content. The only restriction is in when you get to have it. But I realize that for some, there is more satisfaction in being able to eat *whenever* they want, even if what and how much they eat are restricted.
    A couple of comments and questions…
    1. Concerning “metabolic slowdown” you’ve said that the main determinant of metabolic rate is lean body mass, I believe, since muscle is metabolically active tissue. This is true, but isn’t it also true that the process of digestion itself, involving the hard-working smooth muscles of the GI tract, is pretty metabolically intensive? So during the 24 hours of fasting, these muscles would be getting more rest than usual, and that *would* amount to a somewhat reduced metabolic rate. The gut is “expensive tissue,” after all.
    2. During the fasting intervals, one would use stored glycogen and, eventually, glucose from amino acids for those tissues that need glucose. The chemical that the body uses to liberate glycogen and to initiate gluconeogenesis is the stress hormone cortisol, I think. So wouldn’t IF tend to promote higher than usual cortisol levels during the fasting intervals, and is this a good thing?
    Hi Todd–
    Interesting point about different people having a ‘preferred’ vigilance.  Makes sense.  Unfortunately, my vigilance is always greener on the other side of the fence.  If I’m fasting, I want to eat all the time, but restrict my carbs.  If I’m low-carbing, I want to fast every other day and eat whatever I want.  Most of the time, I just suck up and stick with the low-carb regimen, but I often go a long time between meals.  And I never, ever eat between meals.
    As to your questions, first, metabolic rate isn’t just muscle tissue, it is all tissue.  The brain represents about 20% of the metabolic rate irrespective of whether one is eating or not.  Most of the organs–liver, kidney, lungs, heart, and all the rest–work on doing their jobs no matter what the state of eating is.  Even during fasting times, the GI tract has to deal with the food that was eaten earlier, and even if no food is there, the GI tract deals with the vast biomass of bacteria that live there and work with us synergistically.  The GI tract itself is not particularly ‘expensive tissue.’ Current thinking is that during evolutionary times the size of the GI tract was sacrificed to release energy for the much more ‘expensive’ large human brain.
    An old researcher named Max Kleiber who wrote a famous book called ‘The Fire of Life’ back in the 60s figured out that metabolic rates throughout and within species was a function of body weight.  A sheep that weighs as much as a human has pretty much the same metabolic rate.  If you break that metabolic rate down to the individual metabolic rates of all the body components, you find that the sheep heart and the human heart both consume about the same energy.  Same for the kidneys and most of the other organs.  The difference is found in the brains and GI tracts.  Sheep have extremely large, complex GI tracts that consume a lot of energy and small brains that don’t use much.  Humans are just the opposite.  The thinking is that as we evolved larger brains something had to give, and what gave was the GI tract, which became smaller.  A smaller, less complex GI tract needs foods (meat, for example) that is nutritionally dense and easily digestible.
    I don’t know why I got launched off into all that, but the short answer is that fasting doesn’t particularly cause a metabolic slowdown.
    Second, most of the time during fasting, the hormone glucagon,which is the counter-regulatory hormone to insulin, drives gluconeogenesis, not the stress hormone cortisol. 
    Hopes this answers your questions.

  145. Thanks for the clarifications. It was precisely the Aiello/Wheeler “expensive tissue hypothesis” that I was thinking of, and the idea that the brain and gut in some sense were in “competition” for energy.
    Like others, I’m interested in whether there will turn out to be much difference between daily IF (like the program), with a 4 or 5 hour eating window, and the alternate-day (ADIF) system you describe. Another option is one meal a a day, consumed within a single hour. On one meal a day, one is fasting 23 out of every 24 hours, so the duration of fasting is similar to ADIF, but the total time fasting, over a period of a week, would be much greater.
    Let’s see…there are 168 hours in a week. On ADIF there would be 4 intervals of 24-hour fasting, totalling 96 hours. With one meal a day there would be 7 hours of eating and the remaining 161 would be fasting. Of course, even on ADIF there are the sleep intervals, but since they are relatively short I don’t count them as true fasting intervals.
    The question is: Is an hour a day of eating enough? It would have to be true gorging, a Falstaffian meal of calorically dense food. But that seems doable. In a previous life (okay, a month ago), I could easily eat an entire pizza all by myself. I’m not suggesting that this would be the way to do IF, but just as a demo: A single slice of Pizza Hut Sicilian Lasagne Pizza is 310 kcals. Eight slices, the whole pie, would then be 2480 kcals. That would do it. A better option would be based on fatty meat, etc.
    Thus, on this plan, the length of any given fast would be just an hour less than on the ADIF plan, but the number of fasts would be greater.
    Hi Todd–
    The Aiello/Wheeler paper is one of my favorite papers of all time.  I wish I could get a pdf–I would put it up for all to read.
    I don’t really think it matters much if you eat only once per day as long as you get plenty of protein and calories (unless weightloss is your goal).  If you eat a couple of thousand kcals and at least 80 grams of protein, I think you’ll do fine.

  146. I have only tried IF a handful of times over the past 2 years. I can handle the on/off eating requirement. The only problem I constantly encounter are the friends and family members that think I am crazy for doing this. I try to explain all the benefits and have only recently started sending them URLs like this web page and abstracts from PubMed.
    I have had to repeat myself many times that it is not open for debate but many people in my life they seem to think that it will only make me malnourished and unhealthy.
    They can’t dispute the years of positive data in the mice studies but again they think I am crazy assuming it will also work in humans.
    The point of me writing to you is how can I easily make this life change when everyone else in the world lives with the concept that 3 meals per day is the only way.
    People feel as if I am forcing a new religion down their throats.
    Any advice is appreciated,
    Hi Dan–
    Are you forcing the new religion down their throats or are they trying to force the old down yours?
    When I am IFing I simple tell people: No thanks, I ate earlier.  I don’t tell them the particulars or I would probably get the same reaction you do.  Or maybe not.  Most of the people who know me think I’m strange anyway, so the would just probably figure it’s par for the course.
    With the IF as with all dieting, the proof of the pudding is in the eating.  If you do great and improve your health, I’m sure everyone will be asking what new diet you’re following.  So, go forth and be a great example.

  147. A few things here.
    A whole Pizza Hut Sicilian Lasagna Pizza? I can’t even imagine eating a whole pizza hut pie. I find as mentioned above that I feel full a lot sooner than I would otherwise. But now that you’ve mentioned PH, I’m really in the mood.
    As for the rest of the world, I tend not to tell them much either. I spent a week with the parents over the holidays. I was doing “dinner only” style of IF. I just sort of avoided the early meals. Talked a bit about the concept with my roommate, who runs triathlons. Promptly got the assault of, “that’s dangerous, have you tried eating 6 small meals? That’s anorexia, yada yada”.
    Researching this topic has demonstrated, even more than when I started a low carb style of eating, that people develop very strong dietary beliefs, will argue them to exhaustion, and rarely have any scientific basis for those beliefs. Myself included. Every few days I find myself trolling google to make sure my muscles aren’t going to disappear.
    Thanks for the personal replies. Much appreciated. Also glad I’m not the only one who guzzles coffee.
    Speaking of coffee, I find while fasting I need to cut back. The effect is stronger. While this makes logical sense, I’m wondering if anybody had the same reaction?
    Hi Kevin–
    I guzzle coffee whether fasting or not and it doesn’t affect me differently one way or another.
    I, too, have strong dietary beliefs, but I usually have a scientific basis to cling to.  If not, I would be in real trouble.

  148. Hello Doctor,
    I think that it is great that you get around to answering questions and responding to comments here. Thank you very much for your time.
    Anyway, I have been reading a lot of the comments here although I have only got around to about half of them. So I don’t know if anyone has asked this question or if you have discussed it, I apologize for being redundant if you have. But how do you feel about extended periods of fasting? I would love to start an IF program but I’m just looking for a jumpstart. I like instant gratification (as do most people) and I have a significant amount of weight to lose. I know that fasting has been a good way to jumpstart my weight loss. I am thinking about 20 days of a juice fast and then getting into a regular IF routine. ????
    By the way, I already know that the IFing would work for me. When I was at my thinnest, I was doing a form of it without even realizing. I would either eat once or sometimes twice a day but pretty small meals and I’d never snack. I always knew that was what worked for me. But I ignored that fact as I got older and took dieting advice from others. Of course, it was all the same- eat 5 or 6 small meals a day. It never worked! Go figure.
    Thank you for your time
    Hi Vanessa–
    I would not recommend a 20 day juice fast because juice contains no protein and a whole lot of sugar.  You would lose weight, but much of it would be lean body mass, which you really don’t want to lose.  And, the sugar in the juice would continue to stimulate insulin release.  If you undertook the IF and chose to eat extremely low-carb on your eating days, I think you would have more success.
    Keep us posted.

  149. Ok. Thank you for the response! I am quite stubborn and may do a little juice fasting despite your advice but I will certainly let you know how things go once I start my IF routine. One thing that may pose a problem with the low carbing- I don’t care to eat much meat. Is it possible to do a low carb/high protein diet by using mostly fruits and vegetables (low glycemic of course)? Also, I definitely would enjoy drinking calorie free soda and drinks on my fasting days. However, isn’t it true that artificial sweetners are metabolized in the same way that pure sugar is? That would therefore negate some of the positive effects of fasting, no?
    One last thing: I have a friend that suffers from IBS. Would IF help her at all with her condition? I don’t know what all IBS entails but it seems like IF has helped with many other problems, I was just curious on what she may be able to do.
    Thanks again so much!
    Hi Vanessa–
    No, artificial sweeteners are not metabolized the same as pure sugar.  Some of them have their own sets of problems, but they don’t have sugarlike effects.
    I’ve never had experience with the IF and IBS, although just thinking it through, it seems like it should help.  I know that a good low-carb diet helps many people with IBS, and I would try that first.

  150. Intermittent fasting is the way to go. I work a busy schedule and have always been health conscious. I began calorie restricion about 10 years ago, about the same time I heard about Dr. Roy Walford and the failed Biosphere experiment. I was fascinated, and over the the years had become very calorie restrictive, but I was eating every day. Then early last year I went through a difficult period in my life, I just fell off the wagon, food-wise. I began binging at all-u-can-eat buffets and really let myself go physically. It was just so hard to eat restrictive every day for me after, I’d start good then by the end of the day I gorged. I put on the pounds too and lost my “washboard” abs. Then I read about intermittent fasting, the QOD Diet, the Warrior Diet, etc… I started eating every 3 days, the only nourishment I gave myself was post resistance training in the morning, a scoop of multi-purpose protein, a tablespoon of dextrose, a tablespoon of unsweetened cocoa powder, a taplespoon of coffee grinds and a tablespoon of cinnamon. This I would bascially drink down immediately after my workout. All I can say is this – I feel better than I ever have in my short (33 years) life. I have more energy on fasting days, I have my 8-pack abs back and did not lose very much muscle either, which surprised me a great deal because whenever dieting I would always lose a significant amount of muscle mass. I am 5′ 10″, weight 175 lbs, I carry between 4 – 6% body fat and am often mistaken for being much younger. I get the “do you go to college” question all the time. I attribute my youthful appearance and physical health to calorie restriction and a very heavy dependance on vitamin and nutrititional supplements. You name it, I take it. I spend about $3-4K per year on anti-oxidants, phyto-chemicals, resveratol supplements, coral calcium, b-complex, hyaluronic acid, etc… Often when I discuss my lifestyle with people they criticze it and tell me I may be hurting myself. Well if my annual physical has any relevance, let me let it be known EVERYTHING always comes back perfect, I get a very excellent grade by my doctor. I never discuss my lifestyle with him because I don’t want to scare him 🙂 I work out with weights every morning, only taking Sunday off (Sabbath), I swim laps Monday and Wednesday nights and bike, treamdil, or some other physical activity on Friday and Sunday (softball after church Sunday). The people who generally criticize me and make the biggest deal are usually the people who are the most unfit, smokers, obese people, etc. I don’t care what anyone says, it works for me and I hope I live to be 150! At this rate, I believe I’m on the correct path to doing just that :}~
    Hi David–
    Thanks for the inspirational history.  Looks like the IF works for you for sure.

  151. Hello,
    Just a quick comment: I have been doing 18 or 20 hr fasting for a couple years. I started with the WD then went to Lunch and dinner in a 6 hr window. Recently I switched to a small breakfast and a larger lunch and skip the dinner. My question is whether or not there is any advantage to the body in terms of eating at a certain time of the day? I have always heard that eating your larger meal early in the day was more healthful…is there any truth to that, or is it another myth??
    I changed to breakfast and lunch because I have more of a tendency to cheat on carbs at the end of a stressful day! (I am a medical student and have a family to boot!)
    -Thank you for the great info!
    Hi Dan–
    The preponderance of scientific papers seems to indicate that eating earlier in the day is better.  It’s not just a myth.  But whether the advantage holds up with the intermittent fast is anyone’s guess.  I would bet that it does, however.

    Good luck.

  152. I just came across this idea a couple days ago. I have done two days of the 24 hour fast every other day. I find this easy to do which shocks me.
    I am diabetic on Byetta (unable to tolerate Glucophage) I have always had great luck reducing blood sugars with low carb but the uric acid kidney stones has made it more difficult.
    Today’s after supper blood sugar is 130, great results for me. I hope to continue the intermittent fasting and make it part of my overall plan. Spending every other day drinking without eating, I hope, will help decrease overall kidney stone risk along with the alkalizers I use.
    I have also been interested in using one of Dr. Bernstein’s ideas…I read his article on his website regarding weekly rotation of various appetite suppressants herbal and/or prescription.
    I hadn’t given much thought to the tolerance issue on appetite suppressants before but it made sense to me.
    Great idea, fasting!
    Hi Mary–
    Glad the intermittent fasting is working for you.  Keep me posted; I’m really interested to see how it goes with someone who is diabetic.
    I’ve had many conversations with Dr. Bernstein on the many appetite suppressants he uses.  He feels that when they are rotated, they retain their effectiveness longer.  I’ll have to take him at his word because I’ve never really used appetite suppressants myself or with my patients.  Most of my patients have been motivated and came to me to lose weight.  Dr. Bernstein’s patients come to get their diabetes treated and many don’t really care about their weight.  They consider the very-low-carb diet Dr. Bernstein puts them on as a real burden and feel they need some help to stick with it.  Consequently, Dr. Bernstein uses a lot of appetite suppressing strategies to help them.

  153. Above, for shortened eating periods (e.g., eating only between 5 pm and 10 pm), you advised getting at least 80 grams of protein, but I’ve read that the body can only handle (for muscle and organ maintenance) about 15 to 20 grams in a four-hour period. Does the latter rule not apply for a fasting regimen?
    Hi athelstan–
    The idea that the body can handle only 15 to 20 grams of protein in a four-hour period is false.  A nice 16 ounce steak contains about 112 grams of protein, and I can eat one in about 15 minutes–and use the protein.

  154. Hello,
    Thank you for the wonderful description and explanation of this scientific fact.
    My husband and myself are on this kind of IF for already several months after several years on the Banta Diet. We were very successful on Banta but started being worried about missing many essential nutrients. So, after researching pretty much the same set of CR and IF articles and reviews, we worked out a simple eating schedule that suits us perfectly: one meal a day at 7 PM.
    During this meal, we eat all we want quantitatively but we exclude refined carbohydrates and limit saturated fat though recent findings revealed that their bad role is overestimated. We exclude them just to be able to put in ourselves enough good protein and fats like fish, nuts, olive oil and tree nut oils.
    I calculated that we have negative calorie balance around 500 to 900 kcal a day but though we exercise at least 45 min. daily, walking, swimming, and working out with free weights, my stopped losing weight and I continue losing extremely slowly but weight loss is now not our major goal. I now manage my fibromyalgia very well and my husband is on his way to weaning from his anti seizure medication.
    This is just my 2 cents. Maybe somebody can benefit from our experience.
    Tanya Zilberter, PhD
    Hi Tanya–
    Thanks for the report.  I know others who do the one-meal-per-day routine and do very well with it.  Keep us posted on how your fibromyalgia and your husband’s efforts to reduce his seizure meds progress on the regimen. 

  155. I would just like to say – for those who seemed to still be worried about your metabolism slowing down – it doesn’t! Not for me anyway! When I first started fasting, I was lucky to lose even one pound in a day (that’s how sluggish my metabolism was) And all I would consume on those days was black coffee and water. 2 years later, I can go on a fast of nothing but water and black coffee and I will drop 4 lbs overnight. Fasting sped up my metabolism- it didn’t slow it down.
    Hi Sheyla–
    Interesting!  Thanks for the report.

  156. Above, during the fasting intervals you allow taking fish oil supplements. Is this because oil doesn’t stimulate insulin production (although it might compete slightly with stored body fact as an energy source)? Two capsules = 40 calories.
    What about supplement fillers that include small amounts of carbs? Some of mine contain rice powder, for example, although no caloric content is indicated on the label. Should these be avoided during the fasting intervals?
    I’m currently eating only during a five-hour window, from 5 pm to 10 pm (a.k.a. “Fast-five Diet”). I eat a small meal at 5 pm just before leaving work. Dinner includes main course meat and fish or other animal protein in the salad. After increasing the protein as you recommend above, feel stronger and quicker by the day (do the PPLP sprints or squat-jumps some mornings).
    I also tried and liked alternate-day, 24-hour fasting, but figure my current protocol is more paleo-like. Your own low-carb, high-protein diet with sporadic skipped meals probably achieves equal effects. I personally like to include a few more carbs and regular IF may allow this. IF may seem a little less challenging to me as I did a couple Paavo Airola seven-day fasts a long time ago (Loren Cordain is familiar with Airola, the vegetarian health food advocate who died mysteriously.)
    Regarding the current drive (ignoring social encouragement) to eat several times during the day, for hunter-gatherers hunger probably would not have normally led to immediate food consumption, but rather to hunting or gathering, with built-in food consumption delays measured in hours or even days. So as regards the admonition to “eat only when hungry”, I add “but only after a long delay measured in hours, or even multiples of half-days”.
    One body-builder explained to a writer why he never switched to a high-carb diet back in the eighties as all of his weight-lifting friends did. For one thing, he knew that his grandparents ate all of the full-fat animal products on their farm and lived into their nineties. Also, their farmhand, one Indian Joe, ate only meat, intestines, and organs, was built like a body-builder, and only looked 40 when he was 70 years old.
    Hi athelstan–
    I doubt that the supplement fillers and the fish oil will cause a problem with the IF.  When I did it, I was eating at least once a day, so I took my supplements when I took my meal.  Even if you’re going to go all day without food, I still think a few supplements will be okay. 

  157. I’m 70 yrs old, heavy the last 30yrs. & decided it’s time to scale down & tone up because my weight was starting to bother me at 275-lbs. Like Oprah Winfrey & others have said , “Don’t eat after 7:00 pm. I started 01/16/2007 not eating anything after 6:00 pm but water & Daily Pills. Approx.-into 20 days I lost 12-lbs & the next 23 days 3-lbs. I average 14 to 16 hours a night without eating & drink very little water, maybe a glass a night sometimes.During the day I eat anything I want up to 6:00 pm. My daily appetite is getting less of an urge as in the previous readings in this article , I’m not hungry in the morning so I have a slice of toast & peanut butter with my coffee in the am . Later I have a banana for a snack ,sometimes a sandwitch & coffee or milk at noon, little treats during the day & a good dinner at 5:00 to 5:30 pm. Getting the feeling to skip breakfast or lunch lately . Before this nightly fasting I would Binge on treats all evening that got to where I was hooked. After these 43 days I feel comfortable & satisfied with no urge to snack in the evening.Can’t say I don’t think about some Ice Cream now & then .I’m at 260 lbs & holding until I see where this goes.
    Hi George–
    Sorry it has taken me so long to answer, but your comment was one that somehow got hung up in the spam.
    Thanks for the info.  I’m eager to see how you progress with your version of the IF regimen.  It does seem to me that you should have lost more than 15 pounds over 43 days.  I’m wondering what the “little treats” are that you eat throughout the day. 

  158. Have been using SLD/ Shangri-La Diet (not a diet, but a theoritic method for lowering the set point, which also suppresses appetite since December 2, 2007, and on February 1, 2007, combined it with JUDDDD/ Johnson UpDayDownDay Diet (one of the researchers with Laub, I believe). I’m doing very well on the combination. Have lost 30 lbs since October 9, 2007, when I began reducing/restricting my caloric intake. Since December, SLD has reduced appetite to a normal level (no great hunger, no cravings), and I can eat very little (about 450-500 calories) on my “down” or calorie restricted days without hunger, cravings, etc. I enjoy eating now, for the flavor and because I need food to live, and do not feel compulsions to eat, and my desires are geared toward healthy, fresh, nutritiously packed foods.
    I have had myocarditis (evidently viral) since at least 1998, resulting in heart failure/decreased ejection fraction, etc., but am doing excellently (I had ECP therapy from October – December 2006). With the CR IF (JUDDDD), SLD, continuous, gradual weight reduction, exercise, specific nutritional supplementation (Cellfood, StemEnhance, Oxegen BP, Idebenone, Fo-ti (like Resveratrol/Japanese Knotweed), Magnesium, Hawthorne Berry etc., etc., since 2 weeks into ECP and ever since, I feel better than I have in 10 yrs…as energetic and healthy as if I didn’t have CHF…full energy, full breath, etc. My bloodwork profile (done in the 3rd week of December 2006, before IF – JUDDDD, but after first 3 weeks of SLD) is excellent — all numbers in normal and excellent range. I expect with IF of JUDDDD, the next tests will be even better. I beleive that my heart will benefit, not only from the continuing, gradual weight loss and good nutrition, but from the other healthful effects of IF / CR, which may include increased elasticity of heart tissue and more…
    Hi DWB–
    Thanks for the interesting diet history.  Keep me posted as you progress.

  159. Recently, I’ve been trying the JUDDD diet (ADCR) by Dr. Johnson and he includes the following study (by Johnson, Laub, and others) on his JUDDDD website:
    One thing I noticed was that the study gives a different appraisal than do you regarding BDNF, which was lowered during the ADCR diet. The authors infer that this was a good thing, and refer to BDNF as a marker for inflammation, whereas you consider IF-diet heightened BDNF levels beneficial to the brain. Are both views correct?
    I’ve tried a few IF diets, but the JUDDDD really works for me for weight-loss. That’s with eating about 480 calories on the down days.
    Hi athelstan–
    Maybe I’m behind the times, but I’ve never heard of BDNF as being a marker for inflammation.  It is what the name implies, a substance generated in the brain that stimulates the development and growth of new nerve cells.  The Wikipedia definition is the only one that I’ve ever seen.  If people are now saying it’s a marker for inflammation, that’s news to me.
    Thanks for the study.  I hadn’t seem that one yet.

  160. Hello Dr. Eades,
    I enjoy your informative blogs and have just begun reading them since the 2006 winter holidays. Fasting, could that be why I have put on the 20 lbs that I lost? I began taking chromium 2 years ago.I did not change my low carb eating habits of 3 square meals a day. I took chromuim faithfully and began gaining weight.I have been able to maintain my weight but it is frustrating to not be able to lose it again. Should I have eaten less when I started using chromium? I will be fifty in a few days and I am tying peri-menopause and into the weight gain mix.
    I will let you know how it goes Dr. Mike,
    Mary T
    I always considered fasting as being an unhealthy practice. Now I am beginning to see the reasonableness of it.In my college history class, I learned that the British considered the Natives as being lazy and unable of taking care of themselves. Why? They were thin “poorly” clothed and they were not big eaters. As a matter of fact they went many days without eating, especially, during the winter months.In retrospect, after reading increasingly more about the foods of these earlier cultures, I know this helped them to achieve outstanding health. Certainly the frequency of eating should also take credit. You do so much outstanding digging for facts.If you told me down was up, I would believe you! I am going to begin doing the fasting and let you know what happens to me. I must admit, I am afraid because I prefer eating over weightloss.I don’t want to be miserable but this will answer some questions for me. I worry more with breakfast because I work early in the morning. My job is somewhat physically demanding and I want to have energy for this job. However, I have been known to start the day without my A.M. fuel up and I survived just fine. So, I am going to do this and let you know what I discovered. I wish that I had done this the same time that I started adding chromium.
    Hi Mary–
    Good luck with your regimen.  Keep me posted on the outcome.

  161. Hmm gorging yourself on a meal then sleeping or laying around until it was time for the next meal, sounds like a great lifestyle to me. I know that I am not doing this right but I have been eating 2 meals a day. I don’t eat until lunch. I have had big low carb lunches. Yesterday, after a 14 hour fast, I had steak, salad and zucchini. Dinner was a beef patty, mustard greens and sliced avocados. I ate 14 hours later, perhaps not a long enough fast but it really kills me. I had a chicken, spinach, cheese omelet and a sliver of dark chocolate birthday cake with sliced strawberries. I made a huge omelet and filled up easily.I couldn’t finish it but I plan to eat the remains throughout the day if I get any hunger pangs until dinner.
    I am thinking that it is probably not to even say breakfast lunch or dinner. Instead I should say my meal or my daily meal.I will let you know more about my experiment over the next few weeks.
    The biggest challenge will be figuring this out when I go back to a regular work schedule next week.
    Hi Mary–
    Thanks for the update.  I’m curious to hear how it all progresses.

  162. How does this eating method fit into an active lifestyle? I workout 6 days a week, about four of them with great intensity… would eating only once a day allow me to make the personal gains I am achieving? I’m a 24 yom, 5’10”, 175lbs, can deadlift 325 lbs, run a sub 6 minute mile, a sub 20 minute 3 miles, have a 36″ vertical leap and am training for my first marathon, I’ve been able to achieve this eating 6 times a day. I notice significant drop offs in ability if I do not eat pre and post workouts… what studies have been done to help someone in my shoes?
    Hi Corey–
    With the level of activity you’re maintaining, you need to eat more often.  If you are doing fine on the dietary regimen you’re now following, why change?  Especially if you notice a drop off in ability when switching.  If you are interested in making the effort, I would try any new diet for at least a week to allow time for needed enzymatic changes to take place; in other words, give your body a chance to adapt to the new diet before abandoning it.  If you try it for a week and still find your abilities decreasing, go back to what has been working.

  163. One thing that I am very observant of is menses. I think that I am noticing a bigger difference in this more than anything else. I am peri-menopausal and was experiencing longer than normal cycles. Now my last cycle was about a day shorter. Now my cycle was due about 3 days ago but has not yet started. I hope I’m not pregnant ;-). My weight always increases at this time, which it has done but nothing has started yet. I will post more as information comes in.

  164. Hi
    Have been following an IF regime for a few months which works very well.
    My rationale being that in paleo times there was variation in what was eaten and when eating occurred and it would tend to be a few hours after getting up each day.
    Basically, I dont eat till after 12pm (ie no breakfast). I eat basically paleo- whats in season and try and eat game (mainly kangaroo) or pasture fed meat.
    If i’m busy during day (usually 1-3 D/wk) I miss lunch or just have 100g tuna or similar. Dinner is my main meal and except for weekends I try to ensure I cease eating within a couple of hours after dark.
    At the weekends, no breakfast but have lunch and dinner as dictated by social requirements but I try and dodge dairy, grain and sugar.
    This works very well and I find easy to maintain. Im slowly losing weight (current BMI is 24- and will keep an eye on this side so I don’t go below 21)
    I think the timing and variation is a key area for diet exercise sleep etc when trying to mimic paleo “life style” to get the health benefits.
    It would be of interest to hear your views on sleep (especially duration), climatic exposure (eg dowsing\cold showers etc) in the blog at some point.
    I use your basic antioxidant elements ala protein power lifeplan although a little lower in amounts if I can. Have looked for data comparing wild and feedlot style meat and composition of coq10, lipoic acid etc and have not found any. I wonder if you or a reader may have some knowledge of it.
    Thanks for writing your books and the blog.
    Hi Owen–
    I’ve touched on the hot/cold issue in a previous post or two.  Use the search function and put in ‘heat shock protein.’
    I’ll certainly address the sleep issue at some point, although it isn’t something in which I have a huge amount of expertise.
    Keep after it with the IF.  Sounds like it’s working for you.

  165. I started IF yesterday. If you’d like to follow along with my progress, you can do so here…
    Hi Bryan–
    Looks like you’re doing well so far.  It’s not nearly as difficult as a lot of people think it is.
    I’ll keep checking in.  Good luck.

  166. Mattson’s data on I.F. was released several years ago. Has he published nothing since then regarding the benefits of this diet? His silence on the subject is disturbing.
    He’s published much since then, including an article just a couple of months ago on IF and asthma.  Pull up PubMed, enter Mattson MP in the search line, and take a look.  He has continued to publish pretty regularly on IF since his first publication on the subject.

  167. Hello Mike I ran upon this site and read about all the health benefits you say come from an IF style diet.
    I for one have been running an IF diet for the last few weeks tailored around my workouts and body recomposition. I fast for 16 hours and re-feed for 8 every day eg. on a workout day I will fast for 16 hours prior to my WO and upon finishing I will re-feed from 4PM till midnight with complex carbs and protein to help the starved muscle. Taking in appx BMR +25%. I will then go to sleep and fast the next day till 4PM which is a non WO day and I will simply keep calories restricted to appx. 50% BMR with low carb high protein moderate fat.And then repeat.. I have notices an increase in muscle fullness and fat free mass weight has stayed stable but with a loss in bf%. I must say that I will get a bit of stomach grumbling during the hours my body was used to getting food before the diet but it last maybe 5 minutes and dissipates. I’m very happy with the results and think I will make this a long term way of eating.
    Thanks for the report.  Keep us posted.

  168. In your 9/19/06 post- #89, you said “cancer cells can’t use ketones for energy and must turn to glucose to grow and reproduce. Which, in my opinion, makes it almost criminal to put patients with cancer on low-fat, high-carbohydrate diets”.
    Do you rule out the Pritikin diet as a healthy choice for I.F. adherents with cancer? As you know, it IS low fat… but the carbohydrates are complex, not simple.
    By the way, I am very impressed by the attention you give to this site. Thank you.
    Hi Matt–
    No, I don’t think Pritikin is a particularly healthy choice, although if used on an IF basis wouldn’t be as bad.  Still, it’s pretty marginal in protein and totally deficient in good quality fat, both essential for optimal immune response.  And it is the immune system that is the first line of defense against cancer.
    Studies have shown that a ketogenic diet helps in the treatment of malignant brain cancers, which makes sense in view of the fact that cancer cells, unlike normal cells which can use fat, glucose and ketones, can use only glucose.  Keep the glucose low, starve the cancer.

    The fact that blood sugar is so essential for cancers to grow has led to a type of cancer treatment called Insulin Potentiation Therapy (IPT), a controversial treatment involving a combination of insulin and standard chemotherapeutic agents.  The insulin is administered knocking the blood sugar down and basically starving the cancer, making it much more susceptible to the chemotherapy drugs.  In fact, the doses of the chemotherapy drugs are about 10 to 15 percent of what they are in standard chemotherapy, which means that most of the horrible side effects – nausea, hair loss, tremendous fatigue, etc. – are eliminated with IPT.
    Hope this answers your question.

  169. Did my question regarding post #89 get lost in the shuffle, or was it just deemed inappropriate? You said “cancer cells can’t use ketones for energy and must turn to glucose to grow and reproduce. Which, in my opinion, makes it almost criminal to put patients with cancer on low-fat, high-carbohydrate diets”.
    I asked if you would consider the Pritikin diet acceptible for a cancer patient wanting to practice I.F. (i.e. eating Pritikin on the ON days), since it IS low in fat and high in (COMPLEX) carbohydrates. By cancer patient, I mean someone who has been treated for cancer and is now trying to eat well and maximize his chances of remaining cancer free.
    Hi Matt–
    I was just waiting until I got the time to give you a thoughtful answer. 

  170. In their reports of the efficacy of intermittent fasting/alternate day caloric restriction, do Mattson or Johnson/Laub/John make any reference to low carbs? Am I misguided in thinking that merely eating one day and not the next will prove to be as beneficial to my health as these guys imply?
    Thank you.
    No, they make no reference to low-carbs.  No, you are not misguided.  What they say is what the data show.
    I think the very best results are obtained with IF if one follows a low-carb diet on the eating days.

  171. A number of people on the Yahoo Intermittent Fasting group
    have suddenly become aware of the fact that they have very slightly elevated fasting glucose levels. It’s causing some to doubt the safety of long term I.F.
    Do you have an opinion – or possible explanation – for these elevated glucose levels?
    Thank you.
    Hi Margaret–
    My opinion is that if the fasting glucose levels are up slightly, there isn’t much to worry about.  A substantial increase would get my attention.  Having said that, I don’t have a clue as to what the people whose glucose levels have risen are eating during their eating days.  If they’re face down in pastries, bread, pasta, cookies, etc. it shouldn’t be a surprise that glucose levels are up.  What should be the surprise is that they’re not up more.
    In short, I guess, I can’t really make a call unless I have all the data.  In the studies that have been done and published, glucose levels have not increased.  In fact, they’ve decreased.

  172. I REALLY want to try I.F. But I am stopped dead in my tracks when I read that IGF-1 levels go up as much as 15% in Mattson’s I.F. rats. As you surely know, many studies link elevated IGF-1 to an increased risk of cancer.
    This is a real dilemma for me, given the many beneficial effects of I.F.
    What do YOU think?
    Thanks very much.
    Hi Nicholas–
    As far as I know, increased IGF-1 levels don’t cause cancer.  If a cancer is in place there is some, but certainly not conclusive, evidence that elevated levels of IGF-1 can increase the rate of growth.
    I don’t know if the IGF-1 increase in Mattson’s rats is a total IGF-1 or a free IGF-1.  There is a large difference between the two.
    As for me, I wouldn’t worry about it.

  173. But isn’t decreased IGF-1 bad for muslce growth?
    Low IGF-1 doesn’t help muscle growth, that’s for sure.

  174. I want to try this tomorrow, but I am not good at low carb at all, so I am just going to eat regular. The 6 o’ Clock Regimen. Before 6 and After 6.
    Do you think I can reach my goal of 20 pounds at a good rate by doing this?
    Hi Giovanni–
    I don’t know.  If you keep the protein up on your eating days and watch the carbs at least a little,  I think you should lose fairly well.  But, since I don’t know exactly what you’re going to eat, I don’t know what your results will be.
    Good luck–

  175. “
    have suddenly become aware of the fact that they have very slightly elevated fasting glucose levels. It’s causing some to doubt the safety of long term I.F.”
    I think this is a function of “Dawn Phenomenon” possibly an adaptive Paleo holdover. If I skip a protein snack like beef liver or an egg at night before my blood test then FBS is higher.
    Note: These SF packets like Splenda are not a free food as they contain maltodextrin from corn (~1 carb). Stevia packets that contain inulin are O.K.
    Hi Mike–
    You could be right about the Dawn Phenomenon – I don’t know.  I would have to give it some serious thought before I would lay it all at the doorstep of the Dawn Phenomenon, however.

  176. that 24 hour thing ….
    You write that most of the research starves the rats for 24 hours, then work and experiment diligently to design 24 hours for people.
    But surely 24 ratty[*] hours translates into much more than 24 for humans?
    [*]yes, it’s a Python reference
    24 ratty hours does indeed translate into more for humans – probably at least a couple of days.  But it would be difficult to get humans to go that long without eating.

  177. Dr. Eades: I am a 55 year old male, in good health, and reasonably active (I jog 4 miles 4 to 5 days per week). I have currently been fasting on Saturdays (36 hours, till I am a semi-vegetarian. (I occasionally eat meat, but prefer veggies and particularly fruit. I would like to start the IF lifestyle, to lose a few pounds (3 to 5), but mostly to increase health and quality of life. My question is, since you primarily recommend LC eating, what do you think about my eating style and should I change it when starting the IF? If I need extra protein, as you have recommended so often, is there a way to do it without eating so much meat? Thank you for your time and expertise. Randy M.
    Hi Randy–
    You can always get some extra protein, which you do need, by including whey protein shakes on your eating days.

  178. I’ve been alternate day fasting now since May 13/07, and have found it pretty easy. Not a single slip-up. I find it gets easier as I go along too, to the point where I’m kind of indifferent to whether it’s an eating day or a fasting day.
    I go a full day without eating (so I’m fasting 36 hours, and eating no more than 12).
    To better imitate the ratty day in the experiments I could fast two days, and eat for two. I’d fast for exactly the same amount of days per year so calorically it would be the same as I’m doing now.
    Subject to my being able to do it are there any downsides that occur to you? Do you think that this would be a better approximation of the rats’ experimental conditions (with perhaps more likelihood of receiving similar benefits)?
    Hi Ross–
    I don’t see any problems with your regimen as long as you get plenty of calories on your eat days.
    Keep me posted on how it works. 

  179. On second thought… I think that 20 human days would be closer to the rat’s day as a percentage of their lifespan.
    I’m doubtful that 20 human days alternating would be equivalent — the rats wouldn’t be starving in their 24 hour fasting period, just hungry.
    So perhaps trying to match the rat’s day as a percentage of lifespan isn’t critical, although it seems likely that there is some optimal period between 24 hours and 20 days.
    Would two, or even three days fasting be better than one I wonder?
    I don’t know the answer to that question.  It’s probably difficult enough for most people to fast just one day, let alone two or three.

  180. During my fasting hours I am going to try and avoid preparing food, cooking or messing about the kitchen 🙂
    I hope having hot coffee or tea doesn’t affect it.
    “The autonomic innervation of islets plays an important role in the modulation of insulin release from the islet cells of Langherhans. Insulin is secreted at the smell, sight and expectation of food. This is known as the cephalic phase of insulin secretion and is due to the hypothalamo-entero-insular axis which is mediated by vagal nerve[1]
    [1]While MF, Khan CR. The insulin signaling system J. Biol Chem 1994;269: 1-5
    Probably a good idea.  Don’t drive by any bakeries either.  The cephalic phase of insulin release can really drop your blood sugar.

  181. Yes, just working on fractional time equivalents is not great, but it’s far easier than the ideal, which would be to find which genes and gene groups are involved, and how long of a fast it would take to appropriately affect expression or suppression .
    Almost certainly there would also be “diminishing returns”, (I would expect exponentially diminishing, if pure chemistry is involved without genetic “threshold” effects), whereby a 1 day fast might provide 40% of the benefit (number pulled out of thin air), 2 days 65%, 3 days 75% and so forth
    >> So perhaps trying to match the rat’s day as a percentage of lifespan isn’t critical,
    Hi Sam–
    I agree it’s probably not all that critical to match the rat’s day in terms of fasting.  I imagine that whatever degree of rest one can give the liver and the rest of the metabolic machinery is all to the good.

  182. Dr. Eades,
    Thank you for this article.
    My question is: is the IF program you described better overall than the Warrior Diet, in which the participant eats during a 2- or 4-hour window in the evening?
    I struggle with excessive hunger even while sleeping and I find I need to eat right before bed, but I want to know which will actually work better.
    Hi Mollie–
    I think both will probably meet your needs.  Based on your hunger profile, I would think that being able to eat all day might work a little better than just a few hours, but you need to fiddle with it to see what works best for you.

  183. Hi Doctor,
    A question about eating QOD.
    I have been a vegetarian since 16 (no fish no meat) currently I am 29. Up to a few years ago I had the good habit of fasting on Fridays.
    I starting eating QOD 3 weeks ago to get rid of ~8kg (I have no P.M.History whatsoever) and it works great so far. I feel great on the fasting days, and I can feel a nice spiritual effect too.
    However, as I am a nurse my mind keeps questioning, as I am not eating for ~ 34 h every other day (which, again, I have no problem with). —
    Am I not putting too much stress on the pancreas on the off days to produce an increased amt of glucagon every second day?
    I would give this diet full credit as a wt loss solution for a short time, as long as I can go the fasting day with no surrogates. I do not want to eat dinner on fast days, I do not like the idea of ‘diet wafers’ for the blood glucose either. In Christianity and other religions there have been numerous hermits who exalt the virtues of even longer fasting periods and allegedly results are amazing.
    For example, I know of a Christian priest who was seriously ill in his early 60s, DVT and pain in legs due to long distances on foot, got cured through long fasts and addopted regular longer fasting periods afterwards. Some of the spectacular results he achieved were previously brittle nails became strong, having a head full of hair back again (which turned from white to grey) up until the end of his life in his 90s, and being in full strength — in his mid-90s he was still crossing part of the Danube river swimming… a river which is pretty large… He attributed the radical changes on his body to fasting.
    Many mystics were enjoying long fasts seemingly not concerned about medical details, and they regarded it as an effective panacea, which they put into practice, allegedly with great effects.
    However, the nagging question for me still remains — any possible stress on the pancreas re: increased glucagon, can that be a pre-ambule for any later pancreas condition etc.
    Hi Rudra–
    I don’t think you have anything to worry about.  Fasting doesn’t put nearly the stress on the alpha cells – those pancreatic cells that produce glucagon – as eating large amounts of carb puts on the beta cells – the pancreatic cells producing insulin.  I’ve never heard of alpha cells failing as do beta cells from over stimulation.  Since periodic fasting – not by choice, but by necessity – was a common occurrence during our development as a species, I’m pretty sure the alpha cells have evolved to handle making the amounts of glucagon required without a problem.

  184. What is the problem with eating COMPLEX (i.e., unprocessed) carbohydrates. Is a meal of lightly steamed vegetables really unhealthy or in some way inferior to a meal of steak and eggs?
    No, a meal of lightly steamed (or even heavily steamed, for that matter) vegetables isn’t inherently unhealthy (as long as they aren’t potatoes or other high-starch vegetables); it’s just that most of them don’t contain enough of the necessary amino acids to maintain lean body mass.  If you eat those vegetables along with a steak, then you’ve got a good meal.


  185. I was wondering if there are any studies or any experiences you know of that are done with intermittent fasting but are not low-carb based
    do you get the same benefits or will one gain weight eatting one meal a day in there window of eating if there is the typical “American diet” used?
    Hi Mallory–
    The beauty of the intermittent fast is that one can eat a higher-carb diet and still get health benefits.  Most of the studies showing health benefits- if not all – were done on people following typical diets on their eating days.  The long time going without food seems to in some measure undo the bad effects of the higher carbs.  But, having said that, the most healthful approach – in my view, at any rate – would be to eat low carb on the eating days.

  186. hi!
    I am following warrior diet. I eat after 7 p.m. an all day fast. but I eat only low carb high fat products. it is good!

  187. is there anything like potentially dangerous about IF-ing?? I dont need to or want to LOSE weight but I am all about the health benefits and how i have been feeling and how my body seems to be accepting it
    that said if one does not need to lose weight is there anything wrong with still IF-ing?? i dont weigh myself but i do plan on stepping on the scales soon too make sure im not like losing or something
    If an individual is in good health there should be nothing to fear from an intermittent fast.  Consuming plenty of calories on the eating days will pretty much assure that not much – if any – weight loss will occur. 

  188. Hi Michael,
    This blog is so active I couldn’t find a clear answer to my question, so sorry if you’ve already addressed it. If I eat once/day and eat all of my protein in one big lump is it all utilized as protein or will some be converted via gluconeogenesis? Would eating a moderate amount in the “main” meal and then having a small protein meal a few hours later within the IF window work better as far as using that protein goes?
    Hi Iris–
    You don’t force gluconeogenesis by eating protein.  You only undergo gluconeogenesis if your blood sugar levels start to drop too low.  Protein is broken down into its constituent amino acids, which are then used or stored.

  189. I do the warrior diet every day which is intermittent fasting with one meal a day at dinner. Ori Hofmekler, the author of the diet, says that during the fast you are allowed to have a couple pieces of whole fruit like an apple, since fruit goes straight through the stomach and doesn’t put any strain on the digestive system and increases the effect of the detoxification process during the fast. Do you think though that eating fruit would make the fast less effective?
    Probably not.  I don’t buy the idea that fruit goes straight through the stomach and doesn’t put a strain on the digestive system – fruit is digested just like everything else.  And I don’t believe that there is any special detoxifying properties of fruit.  But, having said all that, I doubt that it will make the fast less effective.  What will make the fast less effective is snacking during fasting times, but then it wouldn’t be a fast.

  190. hi! how can i make IF when i make heavy workout early in the morning? after that i go to work.
    Hi georgio–
    Read some of the other comments. Others do just fine with heavy workouts in the morning while IFing. You could eat breakfast, then fast until breakfast the next day on workout days if you don’t feel that you can do your workouts without eating afterwards.

  191. Dr. Eades,
    Can you tell me how IF will affect your gallbladder? I know that if you don’t eat enough fat, your gallbladder is not doing it’s job. I’ve heard that’s why many anorexics, low fatters have their gallbladders fail. Will fasting for 24 hours mess up your gallbladder?
    Hi Kim–
    IF shouldn’t affect your gall bladder at all as long as you eat some fat on your eat days. The gall bladder concentrates cholesterol as part of the bile salts that are squirted out of the gall bladder and mixed in with the fat going down the digestive tract. The cholesterol helps to make the fat better able to be absorbed. With very-low-fat diets, the gall bladder doesn’t squirt its contents out because there is no fat going down the digestive tract. If the very-low-fat diet goes on for a while the cholesterol that is sitting in the stagnant fluid in the gall bladder can begin to form into stones. These stones usually stay in the gall bladder, but sometimes when someone who has been on a low-fat diet for a long time decides to go out and blow it out on pizza or burgers or some other high fat food the trouble can start. What happens is that when this fat comes down the digestive tract the gall bladder squirts out its bile salts to help absorb the fat. But if there are small stones in the gall bladder, these stones can be forced down into the gall bladder ducts, precipitating the agonizing pain of a gall bladder attack, a situation that typically requires surgical intervention. It can all be avoided by eating fat and keeping the gall bladder from letting it’s contents become stagnant.
    Hope this answers your question.

  192. Hello
    Somewhere in your book “Protein Power Lifeplan” you say something like…
    The smallest bite of food will kick-start the body into eating/digesting mode to deal with the nutrients (and wanting more and more ?). Even a sip of water.
    Could you give me the quote, I can’t find it.
    It is this concept that keeps me from snacking during my fasting time.
    To my great delight, I am finding one (evening) meal a day works wonderfully for me. I am 2.6 lbs away from my goal weight and it feels great ! Many thanks.
    Please do find that quote for me. I want to put it on my desktop as a constant reminder.
    Hi Portail–
    I thumbed through the book a half dozen times and couldn’t find such a quote. I had MD look, and she couldn’t find it either. Maybe some of the readers of this blog can dig it out.

  193. It is true though, is it not?
    The digestive system jumps into action the minute we swallow anything?
    And once started, it anticipates more to come. Making us feel more hungry than we would otherwise feel while fasting.
    So a good case for IF is that we give the body a vacation from the work of digesting.

  194. Please forgive the deluge of questions.
    This will be my last… concerning blood pressure.
    I have, and have always had, low blood pressure. When I stand up after sitting a long time, I am dizzy. I have learned to live with it. It is not a huge problem.
    I read somewhere that IF will raise the blood pressure. True ?
    If so, that would be a bonus.
    ps. I follow your Protein-Power Lifeplan Hedonist Approach.
    I started with the Michel Montignac Eat Yourself Slim Method two years ago.
    Hi Portail–
    A study was published a few months ago showing that people who ate one meal per day had a slight increase in blood pressure (about a 6% increase) compared to people who ate the same diet spread over three meals. I don’t think that’s enough data to recommend IF as a blood pressure-raising tool.

  195. I agree.
    Many thanks.
    Thanks also for the intelligent and well researched discussions of the subject.
    All the best

  196. I have spent the past two hours or so reading every comment on this blog and the original blog itself. I find it all very interesting considering I am Pre-Med and hope to go to Medical school one day.
    I’m about to start my second year in college and wanted to know if there would be any fall back on the “IF” if I had followed it “Warrior Fast” style and missed the time period I was giving myself to eat? I’m sure you know that when in college you don’t know what your doing at the same time every day. If I happen to be away from my apartment and miss that time period, would it do any damage to continue fasting all the way to the next eating period? Or would it be more beneficial to just eat when I had the chance and go back to my original time period?
    Hi Michael–
    I don’t think it probably makes that much different one way or another. There’s just not enough data to make those kind of specific calls.

  197. Hi…
    I started the warrior diet(20/4) about 4 months ago. I have gone from 206 pounds to 167 pounds. At first it was hard…. I tryed the 24 hours on…. 24 hours off and didn’t seem to be able to do that, but the 20/4 got easier as I did it. I now can even go out for an hour walk everyday before dinner.
    Now my 2 hour glucose test wasn’t all that good. It was 145…. where last year it was 74. I’m not happy about that, but I am hoping the results are because I am losing so much weight.
    I am a participant in the Diabetic Prevention Program Outcome Study and will go back for bloodwork in February and hoping for better numbers.
    But I am happy with my results so far and will keep it up.
    Just my results from one rat.
    Hi Dyan–
    I’m curious. Did you get a HgbA1c test or simply a 2 hr glucose?
    Keep me posted. I’ve heard of a few people who have had this same outcome, and I’m really interested to see what happens over the longer term. There is no question that a significant weight loss typically reduces overall blood sugar levels, so why have you and others had an increase?

  198. Hi…. Yes I did get a Glycosolated Hemoglobin test it was 5.1 and has always been in this range for the last 8 years. Also my creatinine was 0.9…. I donated a kidney last years. So I keep an eye on that one. Lipid numbers were total…. 196. LDL… 133. HDL….. 47. Triglycerides….80. These numbers were higher then normal too and lower HDL.
    I just figured since I was losing weight that I was now on a high fat diet even though I don’t eat hardly any fat. Trying to not worry to much and just keep doing what I am doing. I have faith I am retraining my body.
    If your HgbA1c isn’t going up, I wouldn’t worry about it. I couldn’t tell from your comment if you were or weren’t eating a higher-fat diet. If not, you’re HDL will indeed fall. If so, I don’t know why your HDL fell.
    Thanks for the feedback.

  199. In both this forum and in the Yahoo intermittent fasting group, I see numerous instances of people reporting that their fasting glucose levels have increased while practicing E.O.D. fasting. And time and again, these reports seem to be doubted, dismissed out of hand or minimized as a legitimate cause for concern. To me, elevated glucose levels seem a MAJOR cause for concern. And they DO seem to be a not uncommon side effect of intermittent fasting. Am I missing something?
    Hi David–
    No, you’re not missing anything. I think the increased fasting blood sugars are an interesting and surprising phenomenon. I wouldn’t get too excited about them, though, unless the HgbA1c levels were rising as well. Anyone who gets blood drawn to check fasting blood sugar ought to have a HgbA1c measure included to see if the increase in fasting blood sugar is just a strange blip or is a measure of an overall rise in blood sugar over time.

  200. Hi… I’m vegetarian and the only fat I eat is my 6 grams of fish oil(which technically makes me not very vegetarian, but I read somewhere that this help to burn fat with exercise) and maybe a table spoon of grape seed oil or olive olive when I cook onions and peppers. I think it was Dr. Fuhrman that said in his book “Eat2Live” that when you lost weight it was like you were on a high fat diet or something like that… LOL Oh and I do eat an occasional avocado on my salad.
    I was thinking the fish oil and walking an hour a day would raise my HDL, but it didn’t. Now I only went from 54 to 47.
    Oh by the way I just got your book “The Protein Power Lifeplan” from the library. I’m hoping I will have non meat options. LOL I actually wandered onto this website because I google Dr. Mattson’s Study on Intermittent fasting. Now I have a new book to read.
    Enjoy your weekend.
    Hi Dyan–
    Hope you enjoy the book.

  201. Hello MR and MD
    I wonder why dietary and nutrition websites dance around the subject of “food addiction”.
    When it comes right down to it, those of us who love food, love to eat, and sometimes eat to excess, have an addiction to food.
    I am thin and healthy, but I have found that IF gives me great relief from this “addiction”.
    Rather than torture myself with three small restricted meals per day, I can eat whatever I want (Protein Power + the occasional bread and dessert when dining out), and leave the table truly satisfied. The only caveat is that it is only once a day. But, that one meal is well worth waiting for.
    Support or suggestions on-line, seem to be only offered by wackos selling snake oil or scary religious based sites (also selling snake oil).
    Why can it not simply be treated as a fact of life. Many (many many) people simply love to eat…to excess.
    I don’t have any doubt that some people are food addicted. For them, I think the intermittent fast is probably the best thing going for all the reasons you mention.

  202. Is there a book to read that would explain all this? I waited until 5:00pm to eat today and it was easy. I eat a high-fat, low carb diet. I ate twice. Once at 5:00 and again at 7:00. I think I ate about 1400 calories… maybe 1500. Does that seem reasonable? And then I am supposed to eat again in the morning and at lunch–stopping at 5:00? I think I could easily do this, but is it certain that I won’t further damage my metabolism or insulin mechanism? I am so sick of making big mistakes with my health and ending up fatter! Where can I learn more?
    Hi Kristi–
    No books out there that I know of. Maybe other readers know of books that I don’t know about. I can’t think of a reason you would damage your metabolism by intermittent fasting, so I wouldn’t worry about that.
    If you’re only eating every other day the 1400 to 1500 calories for a couple of meals actually sounds a little low.

  203. Hey there Kristi
    Just wanted to let you know that there is a new ebook called Eat Stop Eat. It involves 2 24 hour fasts per week & goes into the research & positive benefits of intermittent fasting. I have been really enjoying this book and enjoying my fasting days.
    Hope this helps.

    Hi Brian–
    There are many studies that address IF. You can go to PubMed, put in ‘intermittent fast’ and find a bunch. The studies I’ve read address an IF with a fasting period of a day or less, but there may be some with longer periods of fasting.

  205. Hi ,
    I’m doing some sort of semi-IF .By this I mean that I eat little at breakfast and approximately
    12-13 hours later I eat a big meal in the evening .Do you think it’s beneficial in any way?
    Any extended period without food intake is beneficial. I plan a post on this subject in the near future. Stay tuned.

  206. Hi Mike,
    I thought I’d give you a quick update. I’ve fasted since last November, so 11.5 months in all. Unfortunately though, I’ve just decided to stop. Most of my experience has been positive, but the one negative seems to coincide with what I’ve seen in a study as the main/only downside to IF – increased BP. I’ve had slightly elevated BP before IF’ing, but since IF’ing, it’s been much higher. I’ve tried keeping it under control by eliminating sodium (replacing it with potassium), trying to stay hydrated, consuming cinnamon, doing isometric hand-grip exercises and doing biofeedback breathing exercises. In other words, everything short of drugs. Oh, and I guess short of exercise too, since my schedule has made all but a lunch-time walk a few times a week difficult. I may yet come back to IF, but I think for now it’s more important to get BP under control, and my fitness level up. I’m eating reasonable quantities now and this is easy because I now get to eat throughout the day! I figure I may try my hand at CR at some point, but for now just trying to eat reasonable amounts of food and of course get adequate amounts of protein and keep my carb intake to PP levels. It’s been an interesting year to say the least!
    Hi Levi–
    It bumfuzzles me why your blood pressure has gone up. (Or why anyone’s would go up.) Are you following a low-carb diet during your eating days or are you eating a lot of carbs? I’m curious because one of the virtues of the IF is that it gives people a little more leeway carbwise in their diet. Have you lost weight since starting the IF?

  207. hello Dr Eades. i have asked for comments on this subject from my lowcarbfriends but i need more information. you state that no calorie beverages are okay, my question: since coffee, for example, has an effect on pretty much every organ in the body, is the benefit of the fast lost or lessened by drinking it? benefits like GH secretion just for one. this would also include diet sodas and other concoctions. i developed digestive disorders when i was vegetarian and after years of lc, i conquered IBS but heart burn has not improved at all. IF sounds like the way to go but i may have to do just water throughout the day which, as you know, makes it more difficult. the other problem i see is (believe it or not) weight loss!! i cannot possibly consume my day’s calories in a short time. my tummy would never allow it. i truly need to get a handle on this digestive stuff, though. it truly makes me miserable. IF sounds like it could heal my problem. thanks for the blog! judiblue
    Hi Judith–
    I think the coffee is fine as long as you don’t sweeten it with sugar or put loads of cream in it. When I IF I drink coffee all the time. I don’t drink diet sodas because I don’t particularly like them, but they should be fine also. Except sometimes the sweetness of the artificial sweetener can stimulate a little insulin squirt that runs your blood sugar down and makes you hungry. If you don’t have a problem with that, the diet sodas should be okay.
    Keep me posted as to how your heartburn does on the IF. I’m curious.

  208. Whew, so much has been observed and experimented on this subject. I think that IF has become the most significant piece of dietary information since I began the low carb trek. I know that I did make comments on this and I hope that I am not repeating myself. I know that I had posted that I was able to go 14 hours without eating. I have since expanded that to my goal of fasting for 20 hours and eating within a 4 hour window. On Thanksgiving, I plan on forgoing food until dinner time. I may have some mashed potatoes but, for the most part, the day will be low carb including desserts.
    I have not lost hoards of weight but one thing I have noticed is that my weight is more responsive to exercise. Before, even though I was low carbing, I was gaining weight. I was eating 3-4 meals a day. These meals were spaced well, they were just too often. It was evident that my insulin wasn’t well controlled because I was hungry all the time. Mind you, I was not nearly as ravenous as I was in my pre-low carb days. Now that I have included IF in my daily regimen, I am seeing some positive changes namely appetite control. I go to work without eating.To comment on some other concerns stated throughout this blog, I exercise towards the end of my fasting period and I put off eating for an hour following exercise. Or, I will postpone my workout for 3 hours after eating and eat an hour following the workout. In retrospect, I do everything on an empty stomach now. I do not know what my glucose is but I am not having any detectable insulin spikes. I began doing this after reading about regulating the human growth hormone in Wikipedia and other studies ( including the one in PP ). I am nowhere near being athletic but exercise in some form has always been important to me. I notice that I am developing muscles in my arms. My waist is losing its girth. My body’s mass is decreasing regardless of what the scale says. I really want to stick with this religiously for a year just to see how far I can go. I want to share this information with my family and friends but i don’t let them know what i am doing yet. They will say I am becoming anorexic, which is miles from the truth. I love food, that is not the problem. Food hurts me when I do it too often.
    Dr. Mike, I also read your blog in the anti-inflammatory properties of IF. Low carb has helped greatly with joint pain, but it improved even more after beginning IF.My son is having problems with his sciatic nerve. Not the nerve actually, but the muscle around it. If I understand correctly, the muscle is rubbing against the nerve. He will need to go PT again soon but I am trying to encourage him to do IF and to add coconut oil to his diet. His diet is very low in carbs, naturally. He is not a big carb eater but he could stand to lower them a little more. So as you can see my low carb/IF saga has a long way to go.
    Hi Mary–
    Thanks for giving me a heads up on what’s going on. I’ll be interested in following your progress. I’m planning on IFing myself this holiday season and see if it works to let me enjoy a lot of the stuff I usually avoid while not having to pay the weight gain price.

  209. Hey Mike,
    Just to answer your questions, yes, I’ve generally kept to lc diet as described in Protein Power. I’ve not been perfect, of course, but I think I’ve probably kept consistant 80-90% of the time. My family has a history of heart disease, although I’m not sure about BP except I know that my half-brother, who is not significantly overweight, has been put on medication for it. The relatively new study I saw by Mattson which mentions BP increase is in the American Journal of Clinical Nutrition. For your readers here’s a link to the abstract:
    I could not get access to the full study, but I’m not sure that would help much given the fact that I’m a layman without much technical background in nutrition, medicine, etc.
    Since I started eating 3 meals per day again, I do feel better, but I haven’t checked BP yet since I figured a few days could not really change much…
    Hi Levi–
    Keep me posted as you progress along on the regular eating plan. I assume you’re going back to a PP-style regimen.
    I’m keenly interested.

  210. Wondering if anyone has any updates on IF and weightloss. I have been looking into fasting and came across IF. Its definitely something that has been of interest to me in trying to live a healthier lifestyle, but I wont say that I also need to lose 15-20 lbs. from having two children in the past two years. I’m hoping that IF gives me both the lifestyle I’m looking for but aides me in losing this weight.
    Can anyone provide some weight loss stories and IF
    Hi Jaime–
    I’ll throw it out for the group to comment on. It’s been my experience that IF works okay for weight loss, but probably not as well as a good low-carb diet. The advantage of IF is that on eating days one can eat foods that one can’t eat on a good low-carb diet and still lose some weight.

  211. Hello Jaime,
    i am on IF since Mid-March this year and lost about 10kg (BTW, i am 48 years old). I suspect that i could have lost more if i exercised more and continuously. But given the fact that i have a quite sedentary job and lifestyle altogether, i guess it’s not too bad a result.
    I started with a eat-everything-you-want approach but noticed that within my 3-4 h eating window i tended to eat too much junk carbs (chocolate, potatoe chips etc.) which, as i felt it, slowed down the weigh loss considerably. As i became more and more convinced that low-carb is a healthier dietary lifestyle i switched over and now have the impression that weight loss accelerates again.
    When my wife (not too sportive either) was sure that this is not just one of my temporary spleens she joined me IFing and is quite satisfied wit the results (even though she loses weight slower than me, which is, AFAIK, overall, typical for females.)
    One nice side effect of this way of eating is that i have now a tremendously more precise feeling how much food i *really* need to eat. Which is, btw, considerably less than one would expect. To use an image that Gary Taubes deploys somewhere: As i “live as a tailor” i finally “eat as a tailor”. If i switch to “living as a lumberjack” (= exercise intensely) i am now quite sure that i will eat appropriately (but not more). Hope this helps.

  212. what if you only eat breakfast can you lose weight then?
    That depends on what you eat for breakfast. If you eat 2500 calories of mainly carb, weight loss would be doubtful.

  213. Hello Dr MRE,
    Thanks for keeping up with this post, it continues to provide useful information. I’d like to share something brief about my experience with IF, and ask for your insight: I do not eat bread, pasta, potatoes, etc. Occasionally do eat dessert. I’m very active, and train/exercise 4-5 times a week. My bodyweight is 228 lbs, and I do not know my bf%.
    Using a 20 hour fast/4 hour feeding window (in 8 weeks), I have lost a few lbs. However, the weight loss stalled there. I have not yet had any bloodwork done to compare my lipid values with pre-IF, but have been feeling good. The clarity and self-control have been great bonuses to IF.
    Why has my weight loss stopped, do you think? This week switched to a 24 on/24 off program a la your experience above, and am hoping to see an increase in fat loss due to the extra 4 hours of fasting.
    Does your experience offer any insight?
    Hi Zach–
    It’s hard to say what the problem is. You could be re-composing in that you are building muscle mass and losing fat mass. Or you could be consuming enough calories to maintain your weight. Or you could be reducing your metabolic rate a little due to eating less – as I’ve written numerous times, calories in and calories out are not independent variables. If you reduce calories significantly over the long run, you will reduce you caloric output as well.
    Keep me posted.

  214. HI DR MRE
    The supplements are fine, but the whey protein and fruit/vegetable juices are food, so it you consumed them, you wouldn’t really be fasting.

  215. Kudo’s on the great blog Dr. MRE;
    it seems exercise in the morning during IF might augment Growth Hormone (GH) release. To prevent muscle catabolism for gluconeogenesis, would exogenous amino acids, specifically those that can convert into glucose, be warranted? I’m guessing BCAA’s, Glycine, Alanine.
    Best in Health;

  216. My partner Cherie and I have been doing intermittent fasting since Janury 1st, and so far I am down 12lbs. I feel great, and this is the easiest diet I have ever tried.
    I blogged about my experiences here:
    We haven’t been doing a true fast, and I think that helps. We eat whatever we want from 6:30pm one day to 6:30pm the next. Then for our 24 hours of fasting, we limit ourselves to 400 calories spread out over the day – usually a small yogurt and some veggies.
    Any thoughts on this system?
    Thank you for this thread and your great website. I linked back here from my blog.
    – Chris
    There are no rules for the intermittent fast other than it be intermittent and more or less fasting, which sounds like what you’re doing. If it works, keep on.

  217. If sounds quite interesting. I have a great deal of weight to lose, 100 pounds. I am planning on alternating 20/4 and occasionally 24 hours depending upon how I feel. My brother has used the one meal a day approach to lose weight in the past and it works wonderfully for him. My concern is my seizure meds, can I take those on an empty stomach?
    It depends on what they are. Call your pharmacist or prescribing physician and ask.

  218. This system sounds fantastic, but I have a concern. I am 34 and a Type I diabetic. I take Metphormin, Hummulin and Humalog to control my sugar. Is a IF or Warrior diet plan ok for me to live on, or am I just creating problems for myself? Great blog by the way, very informative.
    I think you could do it, but it would require a lot of vigilance, diligence and help from your diabetes doc. I wouldn’t take it lightly.

  219. When I first read this I was worried about the whole yo-yo low-calorie diet thing which most people face when they try to reduce the calorie intake.
    For some reason, we have all been told that we MUST MUST MUST eat breakfast. And I’ve never been able to work out why beyond the fact that it starts your body burning food.
    However, the more I thought about it, the more it made sense to skip meals… After all, one of the biggest energy consumptions of our body comes from digesting food. So when we have those big breakfasts we are actually stealing all this energy that our brain could be using.
    I think this may be why the IF approach increases BDNF in the brain – because during fasting it is getting a stable input of energy from the body, rather the continuously fluxing which comes from digesting food.
    Fasting towards the end of the day might even help because you are more tired by the time you sleep, which allows more prolonged bouts of REM.
    Who knows? The point is that the advice that has been shoved down our throats for so long may not really be so great after all. Even if it was ‘scientifically deduced’.
    Interesting post by the way.

  220. I agree with Chris above – I have never been able to wake up at 6 and eat a bite before 9am… It has been like this for me since my childhood days and I stopped eating breakfast at age 12. I get so nauseus if I eat before 8am but when I eat after 9am I am fine. If I haven’t eaten by ten I get a so-called hollow feeling on my stomach and then I have to eat.
    Digestion takes up a lot of energy and I am definately not a morning person… I only wake up (mentally) after 9am. I am a little overweight by about 10kg (don’t know how many lbs) and have an underactive thyriod gland (but taking thyroxine pill 0,1mg every day) which results in me having a slower metabolism (according to gp) although I can feel that I can’t have such a slow metabolism as I tend to eat at least 4/5 times a day because I eat when I feel hungry (the hollow feeling on my stomach)
    My question is that if I go on a low carb eating plan combined with the IF – will I still slow my metabolism and gain even more weight?
    Thanks for the post – It is great and please keep up the good work!
    If I go on IF – will I slow my metabolism even more?
    I don’t know the answer to your question. It’s something that you will have to determine yourself. It’s obvious from the disparate comments on this post that mileage indeed varies.

  221. How about low carb diets? Don’t they hurt your kidneys due to too much protein?
    I heard a physician say on tv that it can kill you if you eat too much protein and drink too little water because of the kidneys failing.
    Is this true?
    Please advise?
    The idea that protein hurts the kidneys is a myth. See here.
    Low-carb diets have been used to correct kidney damage. See here.

  222. This is my first time visiting this site. I have read the book Protein Power twice and constantly refer back to it with questions. My husband and I started the diet sometime in January. I have lost 10lbs and my husband has lost 15lbs. Our main goal of this diet was for me to lose weight and to bring down my husbands cholesterol. His cholesterol has been bad since he first had it checked at age 25. We were thrilled when my very slightly elevated cholesterol and triglycerides returned to normal range after being on the diet for only 5 weeks. We anxiously awaited his test results only to find they are worse.
    total- 227
    HDL- 35
    LDL- 175
    The one area where we saw huge improvement was with his triglycerides. They fell from 207 to 87.
    The Dr has recommended medication. We are staying on the diet and trying to add some exercise. If you have any thoughts or recommendations we would be very appreciative.
    I can’t really make medical recommendations over the internet. I don’t know what your husband’s earlier labs were, but I do know that a drop in triglycerides from 207 to 87 is a good thing and indicates that the LDL particle size has probably shifted to the larger, better kind. You need to work through these issues with your physician. If you don’t trust his/her advice, find a physician in whom you have more confidence.
    Good luck.

  223. Dr. Eades,
    I’ve been doing IF since I first read this blog three weeks ago. It hasn’t been a problem to not eat for 24 hours, so I’m sure I can stick with it forever. But to see how much good the regime is doing, and also to make sure it is doing no harm, I would very much appreciate it if you could list the tests you recommend getting, how often, and what to look for in those tests.
    Here in Mexico it’s possible to order tests directly at the lab, and I would prefer to keep an eye on the imporant parameters myself, rather than rely on a doctor.
    I would check fasting insulin levels and fasting glucose. Also, keep an eye on blood pressure.

  224. Are there any new stories on weight loss from intermittent fasting? Has anyone tried IF and not lose weight?
    Doctor, has there been any new research on IF? Has it been definitely linked to increased blood pressure?
    I have had difficulty losing weight on all kinds of diet including lo-carb.
    Just wondering if my metabolism is already shot (which is what I guess) if IF would make it worse.
    I doubt that your metabolism is ‘already shot.’ Some people do great on an IF – others don’t do so great. The only way you’ll know which category you fall into is to give it a try. Keep me posted on how you do if you give it a whirl.

  225. Hi Mike,
    Fascinating stuff. I’ve done the Warrior Diet in the past, so I understand the basic concept (and I do kinda miss the old WD days). I may have to give this a try, especially for the anti-depression benefit (I’ve been on anti-depressants twice in the past and I want it to go away for good).
    I’ve been reading through the posts and wanted to ask if anyone who is highly active has done IF and reported their results? I do martial arts and heavy weight-training and would not want to compromise performance or gains in either case.
    I’ve read that supplementing with l-glutamine can help stave off some muscle loss in the case of CR or very low-carb diets; would it be beneficial during IF? What about branched chain amino acid supplementation?
    I think that both l-glutamine and BCAA supplementation would be helpful.

  226. To Tommi: Joel Marion has some good research and a book written about resetting the metabolism. He’s written some articles on about this subject, such as The Leptin Manifesto. Check it out, as there may be some info there that’ll help you get your metabolism back under control. is his personal site (the January ’08 archives has the article I mentioned).

  227. hi dr. eades,
    i am begining my 2nd week of intermittent fasting and i’m amazed at how easy and great it feels! i eat between 5pm-9pm but consume unlimited water and decaf black coffee and tea during the day, so i’m getting a 20 hour fast in every day. i keep my meals to naturally low carb whole foods (grass-fed pasture finished meats, ocean fish, non starchy vegetables, eggs, butter and olive oil and very small amounts of berries/melon) but plan on trying some portion controlled higher carb whole foods soon. so far, i’ve experienced deeper more restful sleep, more energy for exercise and have much greater clarity of thought. but the biggest plus is simply being really hungry by the time my eating window rolls around..i find that i actually eat much less than before! i think it’s because since i’m eating when i’m really hungry, it’s very easy to recognize when my hunger is satisfied and i stop eating when i’ve really had enough. i’ve experiemented with lots of different eating styles in my day (vegan, low fat, low calorie, traditional low carb, only produce a la joel fuhrman etc) and NONE have felt more natural than IF coupled with low carb. thanks for posting…i never would have heard about this without your delightful blog!
    High Ida–
    Glad to hear you’re doing so well. I, too, found the same phenomenon when I was IFing. I expected that when eat time rolled around I would consume everything in sight, but I ended up not eating all that much more than if I hadn’t fasted for the previous 24 hours.

  228. I’ve been intermittent fasting for about 1.6 years now. I also do at least a couple longer fast (15 days) yearly. I eat every 36 hours, mostly carrot / apple juice, oranges and sometimes toast. I have just recently changed to eating on every 3rd Day now. So I eat about every 80 hours now. I exercise daily and have a busy day job protecting assets of a large Oil & Gas company. I maintain a good weight and well toned muscle mass. Intermittent fasting has allowed my body to completely overhaul itself. I love life and enjoy food, however I have food and my body under my control, this is a wonderful feeling.
    Jordan O’Hara

  229. Hello,
    Do you see any problem with a younger person trying this? I’m 15 and overweight, and figure it’s about time I do something about it. I also plan on doing some exercise, so I was thinking that on the days I’m eating, I will lift weights and do some sit-ups (or if you have any other exercises that might help me lose weight and build muscle mass). Does that sound okay? Great post, by the way.
    Hi Will–
    I don’t see any reason an overweight young person shouldn’t give this a whirl. But I don’t know you and your specific medical history, so I would advise you to check with your own physician before starting.

  230. I tried IF this fall and I found on my fasting days, by early afternoon, I could not concentrate, I was pretty spacey, zoned out and clumsy. For years I used to have a binge day and then for the next couple of days I’d limit myself to about 900 kcal. Since I was eating small amounts frequently I did not experience the effects of low blood sugar very often. Although this was observed to be poor eating behaviour I suppose it wasn’t as bad as it was made out to be.
    I’ve encountered a number of people with this response. Some of the practitioners who use IF actually encourage the intake of a smaller number of calories on the ‘fasting’ days for this very reason.

  231. I just want to post an update on my experience. I continue to IF ( I have been doing it for over a year now ), combined with healthy low carb eating. I exercise, although I have never been athletic, I have also managed to build a liittle muscle. :-). I exercise while I am in my fasting mode and I do not eat for atleast an hour following exercise. My body is responding better to exercise than in the past. Generally I fast for 20 hours and then consume my meals I eat within a 4 hour window. This usually consists of my fast breaking meal and supper. However, with Spring concerts, my schedule has been a little whacko so I have been eating mostly once a day. I am just fine.
    Hey Mary–
    Thanks for the update. I’m glad to hear that you’re still doing so well.

  232. I’ve just started 24-36 hour fasting, thanks to a new article I found tucked away in the latest issue of Men’s Health Magazine. Then I came across your blog here while looking for more info.
    I’ve done 3 fasts, and can honestly say it has been easier than expected, and I do feel great during, and especially right after a fast. I am totally sold.
    Questions though…
    1. You mention coffee as being OK on the fast, which I have been drinking. But I use splenda and a little 2% milk… is that killing my results?
    2. I have religiously taken a multivitamin every morning for 6 years, and don’t feel right about skipping this regimen. Is that ok (or very recommended) while mid-fast, or am I sabotaging my fasting process?
    Thanks for all the research and reporting!!
    I don’t think coffee is a problem, even with a touch of 2% milk. And I think it’s okay to continue supplementation on fasting days. I’m glad you’re doing so well.

  233. I am thoroughly convinced that intermittant fasting is a better way health maintainence. I have been doing it for almost 2 decades. I became pregnant for the first time in 1998 when i told the doctor my eating schedule he insisted i eat according to us guidelines for my babys health and i gained almost 80 lbs in 9 months and had pregnancy complications. I lost the weight quickly by resuming my one meal a day and i fasted on mondays. I became pregnant again in 2002 and this time i stayed on my one meal a day (no fasting) and i gained 20 pounds and had a perfectly healthy pregnancy. When i explained to my doctor my eating routine he told me it was not normal and suggested the same 3-5 meals a day and NO fasting. all i know is that when i eat 3 to 5 meals a day with 6-11 carb servings i became a house and i know that i have been healthy and energetic and i am more active than a lot of my 20 year old neighbors because i do what feels right for my body. My fast begins after Sundays meal and that is usually around 4 pm. I then eat nothing all day Monday and I usually have my first meal on Tuesday morning earlier to break the fast. My eating schedule is a result of my past work schedule. 20 years ago i was deliviering papers at 3 in the morning and then i went straight to college where I stayed all day and then drove to my evening job. I was so poor i did not have money for fast food or to eat out and i found that the only time i had to eat was when i can home at night. After 4 years of this i found that going back to three meals a day just didnt work for me. Especially having quit my morning paper delivery which had me running over 100 flights of stairs wieghted down with papers, it was hard for me to feel like i should be eating 3 carb meals a day.
    I have read you book and readily tell people about it. I appreciate your extensive research and willingness to examine all sides of subject before drawing the conclusion.
    Thank you
    Thanks for providing your interesting nutritional history. It just shows that different strategies work for different people. I’m glad you’re doing so well.

  234. I have been IFing for a week now and I am delighted with living this way… I have gained 60 lbs over the last five years; never had a weight issue until this time. I have tried all kinds of diets but I always found that once I start eating, it becomes difficult to stop. I find it much easier to not eat as in the IF program and then to eat what I want. My experience so far has been that on eating days, I am able to detect satiety whereas in the past I have not been able to do so. I have lost 5lbs in one week. I also enjoy the freedom from worrying, measuring, counting points/calories etc. It is nice not to be concerned with food for 24 hour intervals. Thank you so much…another thing i noticed is that my taste buds have returned….my eating habits were so messed up that I could no longer taste food….it is a gift to be able to relish and meal…I am forty-eight years old and I assume the weight gain I experienced over the last five years is partly the result of aging but I am confident I will continue to lose weight…thanks again, Natalie
    Hi Natalie–
    I’m glad you’ve had such great success. Keep it up.

  235. I just started IFing this week. I’ve been reading up here and I’m doing the daily 18 hour fasts with my window of eating between 12p.m and 6p.m. I’ve only been doing it for 3 days…have plenty of energy and my brain feels very alert but I still feel weird and have a headache. I’m still doing pretty much low carb during my eating windows. On Saturday and part of Sunday I’ll just eat whatever. I’m hoping to see some good benefits and continue doing it. May switch to your version (6pm to 6pm every other day) once I get used to not eating whenever I want and being ok with it.

  236. Dr. Mike, I was doing my regular fast yesterday and had a headache 2 hours before it was time to break my fast. I was going to eat earlier than usual because of that but I took the ketogenic cocktail in Dr. McCleary’s book and I included a magnesium tablet and my headache vanished. just thought you might like to know.
    Hey Mary–
    Thanks for passing your story along.

  237. I’m on my fourth week
    of window “window fasting”
    19 hours (at a minimum)
    of fasting everyday
    with a 5 hour (more or less)
    window for eating
    my eating hours are between 4:00 and 9:00PM
    and also – an important complement to the fasting
    doing interval weight training
    in that time I have lost 11 pounds
    feel highly energized
    and yes
    real hunger pangs
    and stomach growling start
    about an hour before eating time shows up
    and yes food tastes wonderful
    I find I really cannot
    fit in more than one substantial meal
    during the eating interval
    so I usually also have some fruit
    or veggies or a protein shake
    if I want more than that one meal
    this is the best way I have ever found
    to lose weight
    without feeling or being

  238. Hi Dr. Mike –
    Thanks for the informative website, posting and information, as well as “Protein Power,” all of which have been so helpful in my ongoing quest for health and a thin, lean body!
    I’ve been experimenting with various forms of intermittent fasting consistently since June 1 (2008). My goal is to lose 5 pounds and keep it off, which seems like it should be easy, but I’ve tried many approaches over the last few years and none have worked. I maintained my ideal weight (5-8 pounds less than I am now, more toward the bottom of a healthy BMI for me) for 4 years just prior to this so I know it can be done!
    I was really hoping IF would be the answer but so far I haven’t lost any weight at all. Overall, whether fasting or not, my routine tends to be this: very low calorie, low carb (between 500 and 1200 calories depending on whether I am fasting) Mon -Thurs, and 5-6 days a week of intense exercise. I do tend to eat much more (and more carbs) on Saturdays and Sundays. But my average daily caloric intake over the last 2 months has been no more than 1500 calories. According to every “formula” I should be losing weight, but I’ve learned to discount the formulas and do what works for my body. The problem is I can’t figure out what works.
    Do you have any advice? I’ve thought about doing 1-2 36 hour fasts each week as a way to further reduce my weekly caloric intake, because I find that easier than trying to stick to a 1200 calorie a day diet 7 days a a week. Eating is a big part of my social life on the weekends and it is VERY difficult to stick to 1200 calories a day when eating out, going to social events, celebrating holidays etc. But I find it very easy to greatly restrict calories during the week.
    I am concerned however about slowing my metabolism. I’ve read (Eat Stop Eat, Brad Pilon) that this is not the case.
    I would be grateful for any thoughts you have, whenever you have time.
    Thank you!
    I suspect your problem is arising from your weekend eating pattern. Our bodies (including our brains) are sort of giant computers that keep track of all the dieting we have done. If we’ve never dieted, almost anything works in helping us lose weight. Once we’ve dieted a bit, however, things change. The body isn’t so easily fooled. If we eat anything and everything we want at all times, our bodies go into blow-off-excess-energy mode. If then we curtail our food intake, our bodies continue to inefficiently burn calories and we lose weight like crazy. For a while. But then our bodies get smart and start using calories more efficiently and hanging onto weight, and our loss slows or even stops. If, as in your case, the intelligence of the body and brain have figured out that all it has to do is hang on until the weekend when it will again be fed, it will hold on to the weight and wait you out. I fear you’re going to have to suck it up and diet through a few weekends to get the weight-loss wheels turning. Or simply be content with trading the extra five pounds for the benefits being able to eat what you want on the weekends brings you.

  239. Dear Dr. Eades,
    I had been aware of the calorie restriction research of McCay in the 1930s since my medical school when I took an elective course (~1959). I followed that literature somewhat and stayed current with the workings of genes so was galvanized in May 2003 when I learned that a gene was activated by the calorie restriction, learning that intermittant fasting might produce the same results as calorie restriction in rodents. Plus resveratrol also turned on that gene. So I began weekly day-long fasts (supper of day one, no eating except for coffee and wine on day 2 and commenced eating breakfast on day three) and did this until August 2004 when I returned from Europe heavier than I wished. I reasoned then that since it was so easy to do this once weekly I could do it more often and then did from two to three days per week for over a year. I’ve lost track of exactly then I shifted from that regimen to alternate day fasting, to what I read that you and MD did for a few weeks. I allowed myself somewhat greater flexibility in order to suit social events, as follows:
    Sometimes it’s an early dinner with a later one 24 or more hours later, but typically it’s an early breakfast (I and my wife note the time) and then a later one 24 or more hours later. The regimen is that I commence a 24 hour fast almost every day. Thus, as today when I eat with a friend at lunch, I’ll commence my fast today and it’ll go through tomorrow afternoon. I tolerate it better because I sip coffee all the time, caffeinated in the morning and decaf in the afternoon. I drink a glass or two of wine, a beer, or even scotch in the evening (after I’ve done my driving for the day!), this alcohol my only calories in the 24 hours.
    I try for one hour of strenuous exercise per day, as at the gym once or twice a week, which includes weight work, cross trainer and treadmill. Other days I do an hour walk or a total of an hour on nordic track. As an artist now who puts up lots of shows, I sometimes spend many hours doing less extensive exercise that nevertheless “counts.” One day/week I allow myself to not do it.
    My motives entail health, weight control (I’m 20 lb lighter now than Aug 04) and energy (calorie restricted animals can go longer in running wheel conditions before they drop), and less on the longevity itself. If I have health and energy, then longer life’s ok; I’ll take it. I read a factoid somewhere that the CR animals tend to drop over dead without the toll of chronic disease. My internist is happy with my regimen as my lipid indices look good. I have great energy and enjoy health and many interests.
    I tend to eat freely on eating days, and as you pointed out, it tastes very good then! Someone cracked that there is no spice like appetite! So true.
    One of the correspondents mentioned social pressure to eat as others do. I have no trouble on that score in that I’m willing to let folks think me weird. I’m an artist after all after a career as an academic physician who no longer sees patients but contributes to the scientific literature (Indeed, on completion and submission of this, I need to get back to work on a paper that has a deadline!) Some colleagues/friends would have their family life disrupted. Being 70 and living away from my adult children and grandchildren, I find them tolerant and admiring even. My wife does not also fast, but feels relieved at the lessened meal preparation (she does our cooking and this constitutes my way of contributing to the household efforts in addition to cleaning dishes). She is thin and exercises so we together have a high energy life style. We eat out a lot.
    Both of us for approximately the past year have been persuaded by Colin Campbell’s plant based diet ideas and are more or less vegan. I never cheat on the fasting but do take fish oil tablets for their omega-3 content, do eat butter as well as an occasional bacon side order and otherwise do a less fanatic vegan diet of no animal proteins or animal-derived proteins. Not for religious reasons such as sympathy for animals but for health reasons. I’m sure you’re familiar with the China Study book. On the occasion I’ve done a protein feast and then felt nauseous afterwards for a reason that I reason may have to do with my gall bladder being less active.
    In summary I have done at least once weekly day-long fasting for over five years and this extended to alternate day 24-hour fasting for approximately 2 or 3 years. So far my goals of health, weight control and good energy have been realized along with no social or family negative consequences. I do not feel hungry on fasting days and simply forget that I’m doing it, with projects filling in mealtimes. My wife spends more time with her twin sister often while I can remain at the studio with my projects.

  240. This is a wonderful post, Mike, thanks!
    I have been reading a lot about this IF method, but failed to find a good explanation on why it is a healthy practice? I understand that when it comes to the amount of calories consumed, the average number is what matters, but why is it healthy? And why is it considered a method that helps people loss weight?
    No one really knows. My guess is that it allows the liver (the metabolic master organ) have a chance to rest and rehabilitate. Plus it brings about the state of ketosis on fasting days, and more and more it is beginning to be realized that ketones provide better fuel than most anything else. Veech (a major ketone researcher) has shown that the heart runs 29 percent more efficienty on ketones. Plus, ketones reduce reductive stress (a difficult concept to grasp, but one I need to post on someday), which will increase longevity.

  241. Curious as to why reference to SIRT1 genes that produce sirtuin proteins omitted in your response on September 6. These activate with resveratrol as well as with calorie restriction to cause the body to assume, metaphorically described, a thrift economy rather than a wastral-affluent economy. Does intermitttant fasting stimulate these genes too? I’m betting on it but in the meantime, whether or not it does, the side benefit of reduced weight that I seen as a likely result of simply eating less with the every other day diet feels good as do my improved lipid levels.
    Discussion of ketones as fuel reminds me of the natural gas vs oil/gasoline debates! Funny
    I’m sure the SIRT1 genes are involved, and I would bet that IF stimulates them. Thanks for bringing it up. I just didn’t want my answer to get too complicated.

  242. So I am trying to lose weight. I am 165, 22 Female, and only 5’2”. I am trying to get back to 125. I love food, and get very moody and pissed off at the world (just like those rats! ha ha!) because I’m stuck eating a little bit of food every 3 hours. Its such a relief on my cheat day to just relax and not have to keep looking at the clock to see if its been 3 hours. Anyway, I have been aiming at a very low 1300 calories day to lose weight, it works, but I HATE it. So in two days I would consume 2600 calories.
    So if I tried IF, am I correct to think I would only consume say 800 or maybe a little less one day, then 1800 the next, and so on? Would this work too? What do you say? Or should I just do it the way you did it and fast a day until 6 pm, have dinner, wake up, eat breakfast, eat lunch, snack and eat dinner, then fast and not eat until 6 pm the next day?
    Let me know! Thanks!
    You can try it your own way to see if it works. If it does, your problems are solved. If not, then try it my way.

  243. Oh yeah, What about Metabolism? The whole point of me eating every 3 hours is to keep my metabolism high.
    Wouldn’t my body think I was ‘starving’ myself and hold on to all the fat?
    If you kick up your intake on the eat days, your metabolism should be fine.

  244. Melissa B., for more info on the kind of scheme you’re thinking about trying, see Dr. Johnson’s recent “The Alternate-Day Diet” book. A brief description can be found on its website .

  245. Dr. Eades,
    Perhaps this was already addressed years ago (literally) but in your post (I found it through IronOnline) you wrote, “When researchers restrict the caloric intake of a group of lab animals to about 30 to 40 percent of that of their ad libitum (all they want to eat) fed counterparts … ” the CR animals lived 30 percent longer.
    In the next paragraph you wrote, “it stands to reason that if humans reduced their caloric intake by 30-40 percent for their entire lives, they would also live longer.”
    But the way you wrote the post, they didn’t restrict it 30 to 40 percent — they restricted it TO 30 to 40 percent of the total … meaning they restricted it by 60 to 70 percent. Did you mean all the numbers to be 30 to 40 percent:
    * 30 to 40 percent fewer calories (the study)
    * 30 to 40 percent longer life (for the thusly CRed animals)
    * 30 to 40 percent fewer calories (for human) would lead to longer life
    I meant restricted by 30-40 percent. It would mean they would consume 60-70 percent of their former ad lib diet. Sorry for the confusion.

  246. 44 year-old male here. My experience – all positive – so far.
    I started intemittent fasting in August 2005, so at time of typing, I’ve been doing it for
    The regime is simple – eat one day, NOTHING the next, so including sleeping hours, it works out at 14/34 in terms of hours eating/hours fasting for every 48 hour period. The only things I consume during fasting days are water, tea and coffee (no sugar!) with a tiny bit of milk.
    I also excercise, burning off 1000 calories in 55 minutes on a lateral trainer, on fasting or eating days, there’s no effect on my ability to do so. At the moment, I’ve slipped to just once a week, but I also briskly walk a minimum of twenty miles each week.
    Weight: Lost 30 lbs during the first year, nothing after, but if I up the exercise, I do lose more. My weight is therefore remarkably stable for someone who has in the past fluctuated quite a bit when not exercising.
    Pulse: Has been down to 47, usually averages 60.
    Blood Pressure: 120/70 – not that impressive, one study showed an average for this diet of 100/60.
    Blood Sugar: Low.
    Food: You really appreciate it more. Eating daily, you just take it for granted.
    Time: An extra two to three hours spare time on fasting days.
    Illness: NONE. Colds – NONE. Flues – NONE. Coughs – NONE.
    The last seems to be the most remarkable benefit of this regime. And you’ll only be hungry for the first seven or eight months. After that, it’s a breeze.
    Thanks for the dietary history. It’s nice to see how different people respond.

  247. What about diabetics? I haven’t read through all the responses above, but I’m anxious to know how diabetics respond without eating.
    Type II diabetics get better, type i diabetics significantly reduce their insulin doses.

  248. Also, I have NASH (Non-Alcoholic Steatohepatitis) and high blood pressure.
    These improve as well, especially the NASH.

  249. Dr. Eads, I am confused.
    I read with great interest you post above and people’s great experiences with IF. However, when I followed the link to you article on this site:
    I found the following at the end of Part II:
    “It’s looking like the intermittent fast is another of those ideas in science that looks good in animal studies then not so good in human studies, proving once again that rats and mice aren’t simply furry little humans. And it appears – for humans, at least – that the intermittent fast is indeed beginning to look like the reality of a late-night gimmicky infomercial: long on promises, short on delivery. I suspect that it is also a cautionary tale about the applicability of caloric restriction studies to humans.
    Sorry to be the bearer of bad news, but that’s the way science sometimes works. Lab results and reality are often two different animals.”
    So, what is your current recommendation on IF? Is it worthy or the result of human study which you mention (“Papers appeared showing that subjects IFing, or even regularly skipping a couple of meals per day, were developing insulin resistance, impaired glucose tolerance, elevated blood pressure, and decreased thermogenesis”) negate the value of IFing?
    I’d appreciate your clarification
    The jury is still out on the subject. I’m going to do another post on IF soon, so I’ll give you an update then.

  250. Following the warrior diet for two weeks now. Fantastic results. Trememdous energy, fat loss, mental clarity, breathing better. I have a lot of weight to lose, but will not weigh to avoid moood swings and since the benefits of this is so much more than weight loss. One pecular note is, for years I have had very brief, very clotty, very painful periods. This month the cramps and all the other symptoms were greatly relieved, and my period is light and clot free, but it seems to be going on much longer. Im use to a three day period, this one has lasted almost two weeks. This morning it seems its stopping finally. Can this possibly be to the fact that I have been insulin resistant for so long and now Im stirring things up? Ive had tremendous stress over the last six months, storm related displacement, job loss, friends scattered. May be stress and then the diet has things changing.
    It’s more likely that the changes are coming from the estrogen stored in your fat cells that is now being released.

  251. Just a note to report that today, for the first time in my 39 years, I comfortably did sprints throughout my 45 minute walk. I have been over weight and energy compromised ever since childhood. Running with freedom and energy instead of pain and dread is something I’ve literally dreamed about, but never experienced until today. To have this kind of phycial development a few months before you turn 40 is truly mind boggling. Words fail me in trying to express my gratfulness to the warrior diet, and all the outspoken people who go out on a limb and state their reality, no matter how much it goes against the grain of the current beliefs. Thanks everyone!!!

  252. Hi doc!
    Thanks for your interesting blog. We are very much interested in IF, but a few worries remain:
    1 How will it affect someone who is already underweight? I definitely do not want my husband to loose any more weight, he is 60 kg and 1.84 m tall. There are no known health problems.
    2 Personally I want to stick to my diet of fruits, steamed vegetables, salads, nuts and seeds. I am looking at the volume of the needed food every alternate day, which seems too much, I already feel it is high volume even when not doing IF. Do you know of people who have done this? Do you have any recommendations?
    Eagerly awaiting your reply!
    Thank you!
    I know a lot of people, myself included, who have done IF. Just eat what you want on eat days and don’t worry about it, then don’t eat, or eat just a small amount – maybe a protein shake – on the fast days.
    If your husband keeps up his caloric intake on the eat days, he shouldn’t have a problem with weight loss.

  253. Here is an update on my progress. This is how I now define my eating lifestyle…my dietary lifestyle is low carb all the way. Intermittent fasting is how I control my meal frequencies and it is what I use to keep my weight at healthy levels. I began IF in 2007 to lose my regained weight. I knew that it would be slow going because of my age and the the character of my body. Now, I can say that the results are astounding. I went from 166 lbs to 136 lbs ( on good days ). What I love the most about IF is when it is time to eat I literally pig-out. I don’t think about portion control, I have increased the amount of fats in my food. I drink heavy cream in my coffee. I also drink coconut milk smoothies in which I add whey protein powder and mct oil. I have plenty of energy to get me through the day and I am pleasant at work. I caught my reflection in the window today at work and I really liked what I saw. I have had no illnesses ( no colds or flu ). My gums are pink. I am African-American and read where it is normal for “us” to have dark gums. My gums had flecks of black or blue throughout my mouth. Now they are totally pink. That was something I had not expected at all so I am not sure if it is due to the dietary lifestyle, the fats or my braces. I don’t know but I am being transformed.
    I am planning to work up to a 5K run just to see if it can be done. I also want to compare it to my other runs.
    That’s it for now,
    Fabulous! I’m thrilled to hear that you’ve done so well. Keep after it and keep us all posted.

  254. Don’t mean to hog the blog , but had a pretty big event today. Did my usual sprinting at my walking session. Felt stronger than ever. Later, before I broke my fast, I decided to do a few minutes trying out some kettlebell moves. Very heavy weight 12kg. wellllllllll The exercise itself was exhilarating. I punched it out as hard as I possibly could, felt great. Collapsed on the couch,,,,,very pleased with myself, then started tingling in my extremities, even my lips and tongue. No SOB, no chest pain, maybe a little light headed later after I started to freak out over the tingling. Just got online and can see that it could have been low blood sugar, low calcium. Feeling much better now, but may forgo the more intense weight training until I develop more endurance??
    My bet would be low-blood sugar. Working out intensely requires a lot of blood sugar, since most such workouts are anaerobic. Blood sugar can fall in a hurry, sometimes more quickly than your liver can replace it. And you experience the symptoms you described. As you do such exercises more, you should grease the skids of your metabolism so that this doesn’t happen as often or as severely.

  255. Is there any reason to be concerned about vitamin/mineral intake problems with the addition of fasting days? The traditional notion is that we need a certain amount of vitamins and minerals each DAY in order to maintain strong health. Would you say that this is perhaps an oversimplification and that the body can function healthily with a more random scheduling of vitamin/mineral intake? Or, on the other hand, should an IFer reasonably be concerned about negatively impacting their intake?
    Many IFers take daily vitamins. Since these are non-caloric, they don’t really impact the IF. But I don’t think it’s a problem to take them on an every-other-day basis.

  256. I have a question! I have been IFing since Jan 1st. I’m eating once a day between 2-3 pm. I am eating what I normally would during this time. Chicken, pasta, turkey burgers… any type of turkey dishes (turkey meatballs w. spaghetti), one night i had tacos.. with turkey instead of beef. I don’t eat any sweets because I’m usually full once I’m finished eating my meal. I also work out for 40 minutes 5 days a week. I started at 125lbs and so far I’ve only lost 1lb! Does anyone have any good advice on what more I could be doing to increase my weight loss?? I feel alot better since I’ve began but I’d like to see a little more weight loss. Please help, and thanks!
    At 125 pounds, it doesn’t sound like you’ve got a lot to lose. All I can suggest is to cut the calories a little more on your eat days.

  257. We have been doing IF for 7 days now. It is an experiment. We will see where it will take us!
    Now we have a question. Does it make sense to have fasting and eating days on fixed days of the week? That would involve either 4 fasting and 3 eating days ‘every’ week, or 3 fasting and 4 eat days ‘every’ week. Do you see the point? Rather than a scheme which involves 2 weeks. It would be much more practical for us to have our fixed fasting days, but since that involves eating for 2 days in a row once a week, does that disturb the body in any way? Does it matter? I can imagine when the body is expecting a fast, and then you eat, that it does not take that nicely. What do you think?
    I don’t think it really matters.

  258. Dr. Mike,
    Something that I have been pondering is- if the body is in ketosis, and ketosis is as efficient as you say, wouldn’t the body be better equipped to absorb nutrients ? For one, the cells are not clogged with an over abundance of glucose plus ketones are aplenty. The organs are functioning at their peak performance. It just seems to me that ketosis would increase one’s ability to absorb nutrients.
    There is a difference between absorbing nutrients and absorbing calories. If all systems are working better – including the digestive tract – nutrients would be more likely to be better absorbed. Calories would also be absorbed, but would get burned off more easily during ketogenesis.

  259. lost 15lbs in one month of IF’ing~ body composition is much changed so Im sure this is a fat loss as opposed to my former losses of water/muscle/fat. lowering intensity of resistance training has decreased my post workout tingling sensation to the bottoms of my feet, so the blood sugar theory was spot on. will keep intensity lower until my body adjusts in few weeks/months. took a break in week four, took two days of random junkfood to get back to pre warrior diet lethargy, cravings, and foggy thinking. took two more days of IT’ing to get back to the “runners high” “fatty acid flush” energy levels i had gotten used to. Ive decided that for me, the best way to cheat and enjoy pleasure foods from now on is to eat them in my window at night. eating during the day is simply too disturbing to my physiology. looking forward to my second month!

  260. tangent question: since in all my readings you seem to be the most intelligent, with fewer ideologies, ill ask you this, if you deplete your glycogen stores in a couple of weeks of IT’ing, and then the body switches to a different fuel source ie fatty acids and ketones, will you stop using ketones if you eat more than 100 carbs a day? i do eat more than 100 carbs a day. i am a recovering carb junky and don’t feel a need to be in ketosis for my primary goals. do you see any extra benefits from keeping your carb count so low?
    You sure know how to butter a guy up. 🙂
    You may or may not stop producing a lot of ketones at 100 g carbs per day. Most people, even if they are on a higher carb diet (unless they graze all the time) will be producing some ketones at times throughout the day. If you are doing okay moving toward your primary goal (whatever that may be) I don’t think it’s all that necessary to be in ketosis all day long.

  261. Dear Dr. Eades,
    After 10 months of strict alternate fasting (24hrs eating, 24hrs fasting) my metabolic profile does not look like it is improving.
    As I understand it, the reason why alternate fasting is thought to make people live longer and better is because it positively affects the metabolic profile. Since that is not changing I wonder if you’d be so kind as to tell me whether you would recommend sticking with intermittent fasting for another while or trying something else, such as caloric restriction?
    Below you’ll see my metabolic profile at 0, 3 and 10 months into the intermittent fasting diet.
    Thank you very much,
    March 08 June 08 January 09
    Serum Glucose 78 89 96
    Serum Insulin 5.5 7.8 6.1
    Glycosylated hemog. 5.6 5.2 5.5
    Blood pressure 100/70 100/70 90/60
    Weight 80 76 80
    Total Colesterol 232 193 229
    HDL 38 42 38
    LDL 169 128 167
    Triglycerides 127 117 122
    First, I’m sorry it has taken me so long to respond. Your comment – along with a number of others – for some reason got caught in my spam filter.
    I can’t tell you what I think because I have no idea what your doing on your intermittent fast. It no doubt makes a difference if you are eating huge numbers of carb calories on you eating days or if you are eating a low-carb diet on your eating days. I don’t have enough information to give intelligent advice, but even if I did, I couldn’t because you are not a patient of mine. I can’t give specific nutritional advice over the internet to people I have never taken care of.
    Having said that, however, your profile doesn’t look all that bad to me.

  262. Here is something that I have noticed. Back when I was weighing 142 lbs. My waistline hovered between 30” and 32”. I gained about 24 lbs within a 2 year period. I began to implement IF and I last weighed in at 145 lbs ( my weight fluctuates a lot ). But my waist is 29 inches. Also, when I began IF I was low carbing…I will always be a low carber. I believe that my carbs are around 30 grams/day plus I increased my fats. I add fats to my diet every chance I get. Just wanted to add this for you to ponder, Mike.

  263. It is interesting to consider that our current ‘educated’ society is one of the only times throughout history where fasting of any kind is shunned.
    In most societies, both eastern and western, periods of fasting where common. Generally it was one day of fasting per week.
    It is hard to say the effects of this, and whether this stems from religion, a lack of food or a health benefit is anyones guess. (Religions for some reason have always encouraged fasting?)
    As usual, I’m keen to try this, but I can just imagine the reaction of other people. My family would go on about how it is “unhealthy” until I finally eat something just to shut them up.
    *Sigh* LOL
    Dr. Eades,
    If you had to pick an ‘ultimate nutritional approach to health and longevity’ what would it be?
    Low Carb?
    Low GI?
    Gluten Free?
    What would the diet consist of mostly?
    Fruits & Vegetables?
    Breads and Grains?
    Probably low-carb modified intermittent fasting, which is basically what I do myself most of the time.

  264. took things things to new level: skipped an eating window moday night and had a forty hour fast. decided when i rarely have no appetite for my nightly feed, i will do the eatstopeat approach and do a overt fast. workouts on both days went fantastic. no low blood sugar symptoms, energy levels high. my body must be adjusting quickly to the program im on, a combination of fast five/warrior principles. im so impressed with my results ive decided to incorporate this weekly fast permenately. ive read visceral fat release is more responsive to calorie restriction than exercise, so this my expedite my belly lose. i would much rather fast a day or two a week than eat light meals. just my weakness.

  265. Hi! Great blog. I have read every single comment and I want to try this but I am still very curious about the “technical stuff.”
    I was wondering- does the process of muscle wasting only occur after all fat stores are used up or is there a specific point (varied, I assume, from person to person) after which fasting for so many hours/days where muscle is used for energy? If so, would it then be more effective to fast to this point and then begin re-feeding so that fat stores have dissolved and lean muscle mass remains intact?
    So much of what I have read says that fasting, at any length past 3 hours to maybe 24 it seems, means that your next meal, regardless of what it is comprised of fat/carb/protein, will be stored as fat… or something along the lines of- your body is more sensitive post-fast to calories somehow and shifts to “fat storing mode” in response to the fast.
    I have also read that anorexics (And yes, I understand this is a different thing than IF all together) can start out with a normal BMI and become severely underweight but that during recovery they gain back the weight very quickly, usually in the form of fat. Is this because of the types of food that they are required to eat in a re-feeding plan? Or does it have to do with the body’s own response (being more sensitive) to storing calories as fat after a long period of under-eating? I was curious about what you have to say about that.
    It seems that the IF approach combined with LC eating on the non fast days would be optimal when it comes to the burning of stored fat. I am already an LC eater and am eager to add IF to my routine. How long can this usually be done before a plateau occurs or will a person continue to lose weight consistently and perhaps reach an unhealthy underweight state? If anything, I assume this varies from person to person… so I guess I’ll give it a go and see what happens with my own bod.
    Chris (female)
    Sorry for the delay in putting up your comment, but it got caught in my spam filter. And I don’t know why since it contains no links (a sure way to gain a trip to the spam basin).
    Muscle loss doesn’t occur after the loss of fat stores, but after the loss of glycogen stores. Muscle is the repository of amino acids, which are converted to glucose in the gluconeogenic process. If you are IFing, you shouldn’t lose much – if any – muscle mass, and any you might lose will get picked back up the next day.
    It is not true that if you fast for any length of time, whatever you regain will all fat. When people do go on long-term severely restricted diets (anorexics, for example), they drop their metabolic rates. When they refeed, they tend to put more on as fat simply because they have adapted to the lower-caloric intake. The nice thing about IFing is that typically people eat enough on the eat days to prevent their metabolic rate from plummeting.

  266. Fascinating stuff. I already eat very healthily (Vegan) but this could explain the last little bit of abdominal fat.
    Too much fruit sugar I guess, I never eat processed stuff apart from rye bread and soy yoghurt.
    Quite a lot to get into my head but I am trying it. So many different variations, fast all day everyday, every other day, normal carb, low carb….
    But thanks for such a useful site.
    I’m glad you enjoyed it.

  267. I just started IF this week. Today would be my 2nd fast day and so far no problem. I do have a question though, is it okay to eat sugar-free gum or candy during fast days. And what other beverages could be consumed during fast days besides water?
    No problem with the sugar-free gum because it contains no calories. Not so with the sugar-free candy. I would leave it alone. Any non-caloric beverage should be okay.

  268. Quick question! Do you believe there could be any benefit to drinking green tea during the fasting phase, purely to relieve any of the metabolism slow-down of which we are constantly warned?
    I don’t think it would hurt. But if your eating a little more on the non-fasting days, your metabolism shouldn’t suffer.

  269. Sorry to blog on a forum but: Wow! I did two weeks of every other day fasting, along with my nightly eating window. The window of eating has been the key to maintaining any ground Ive gained on my overt water fasts. It was aggressive and it was challenging, but Im so happy to report that the two weeks of intermittent water fasting has totally knocked out my almost constant pms cramps. The estrogen dumping must have been amped up considerably. The tingly low blood sugar/pressure (?) has been totally alleviated even though I keep uping the intensity of my exercise. Im dealing with a little nausea in the am, and some mucus expelling from the lungs, bowels, but its all detox and I welcome it. Eating in my window every night for the last week has simply continued the cleansing process to a deeper level. The first half of my window is all raw, fruits/veggies. I marvel at how much cleansing and healing can take place without overt fasting for days and weeks on end. Truly awesome!
    Glad to hear you’ve done so well. Keep it up.

  270. i’ve noticed that once i start eating on a given day i am hungry the rest of the day. fasting has worked well for me from time to time but seems to catch up with me during competitive physical events.
    i too read the warrior diet and the author recommended eating berries if you got hungry during the day.

  271. Hi There,
    I’ve read a lot of your posts and really like to give this a try. One of my vice’s is diet cola drinks.
    I see that you say non caloric drinks are fine but I’ve recently read how sweeteners (aspartame, etc.) slow down the fat burning process as they over work the liver etc and you don’t get rid of the fat. What are your thoughts?
    I don’t drink diet drinks with aspartame, but not because they prevent fat burning. I prefer those made with Splenda, but any non-caloric beverage shouldn’t cause a problem with the IF.

  272. Here is something that I have been doing…I add about a tablespoon of MCT oil to my morning coffee. Although it does have calories it goes directly to the liver causing a rapid ketone increase. If I am not mistaken, isn’t this unique to other caloric sources? I have a sustained energy boost throughout the day and my mind is clear.
    MCTs absorb directly into the circulation instead of going through the lymphatics as do the longer-chain fats.

  273. I was introduced to IF as “Daily IF”, being – eating everyday, but in a shorter window. The ultimate goal being eating everyday but all calories in a 4-6 hour window. Therefore I have been on a few days of eating only between 3pm and 7pm. I’m quite certain my caloric intake is somewhat below what it would be if I were eating regularly everyday, however energy is fine so far. I train in crossfit everyday and haven’t yet noticed a decrease in performance. I would be interested in your comments on Daily IF as opposed to “day on day off”..
    The idea of IF is so new that no one really knows what is optimal. If it’s working for you, then I would stick with it.

  274. I read about this on Monday of this week and thought I’d give it a try starting Tuesday (I fasted on Tuesday). I’m 13st, 6,2″, male, under 25, and not very active (I work from home, on my computer, and get very little exercise as I’m not involved in team sport / enrolled to the local gym).
    I’ve been drinking sugar-free squash (checked the nutritional label, only contains trace amounts of anything) and water on fasting days, and as you mentioned in your article (this had only vaguely occurred to me) I’ve been fasting for over 24 hours at a time.
    I was somewhat relieved to read your answer regarding protein; I too was under the impression that if I were to do this long-term, on fasting days my body would gradually eat away at lean tissue, leaving fat tissue.
    On Tuesday I felt a little lightheaded and at one point, nauseous, but not at all hungry. For most of the afternoon I had a headache, but it wasn’t bad enough that it stopped me from working, nor disturbed my sleep (I still had it as I fell to sleep). I didn’t take anything for it because I didn’t know if paracetamol might be harmful on an empty stomach!
    I say I wasn’t hungry at all, I didn’t have a stomach ache, but it was very mild, and entirely tolerable.
    On Wednesday I ate Subway for breakfast, fried mushrooms bacon x2 and eggs x2 for lunch (cooked in a non-stick frying pan so I didn’t add any oil) and half a large seasoned rotisserie chicken (from the supermarket; already cooked and still hot) with about 130g of salad (I’m lazy, so I buy bags of salad). And several slices of granary bread. Apologies for the excessive detail!
    Today I’ve eaten nothing, experienced no lightheadedness (is that a word…) or nausea or headaches, and although my stomach feels a little hungry, not particularly. Incidentally, I’ve been drinking about 3 litres of water a day; some of that from green tea but none from carbonated/caffeinated beverages. Ordinarily I drink perhaps one litre a day, so this is a marked improvement. I’m not particularly health conscious; I’m doing this in aid of the prospective increase in cognitive ability, and reduction in the effects of stress, both of which would be greatly beneficial!
    If I start twittering about this, I’ll add the link on here :).

  275. Hi. I’ve combined daily IF with skipping eating windows occassionally. so far so great. just takes it a step further. if you skip eating window to eating window, you basically have about a forty to forty three hour fast. it was very effective for me. but only did it for two weeks. now im back to eating everynight for now. daily fast have done wonderfuls for me, and that may be optimal for someone so atheletic. you just have to try things out and see how you personal respond. i was quite tired the day after i skipped my window, but im not a big trainer, so no harm for me.

  276. Back again.. on week two of intermittent fasting. I have to say, I am blown away by how much food I was eating before. I hate to say, but mindlessly eating, or eating because the clock said 8:00 am 12 noon and 5pm oh and those “snacks” your supposed to get in to make up the 5-6 smaller meals a day. I have not been hungry and so not eating until physically felt hungry. Easily able to sustain until 2-3 pm in the afternoon and then eating a good paleo meal and snacks for 4 or 5 hours. I’m full going to bed, not waking hungry and have found a few extra hours of time during the day because morning isn’t held up by making breakfast, and lunch isn’t an hour long break anymore. I’ve definately noticed a shift in body shape, a little lighter and never bloated! It’s so easily tweaked too, if the day calls for a certain lunch appointment I just start at noon and end at 4 or 5, of if I have to go out for a later dinner, just start later in the day…. so easy and effective.

  277. I have to take blood pressure and anxiety meds every morning and evening. Will taking my meds interrupt the fast?
    No, but the fast could cause a problem with your meds, especially the high blood pressure meds. You should check with your doctor and be careful.

  278. Hi Dr. Eades,
    I have been reading your blog & every single comment for the past 2 days & nights. I just discovered IF after many, what some might call failed attempts to complete 10 days on the Master Cleanse (the most I could ever do if 7 days) but the mental part of it kills me every time! I just become a basket case.
    On March 1st 09, I decided to do my own version of IF where I drink 1 – 3 glasses of the MC lemonade (1 tbsp organic maple syrup or blackstrap molasses or agave nectur, 2 tbsp lemon juice & a pinch of cayenne pepper) and/or fruit juice on 2 1/2 fasting days (totally about 150cals) and eat whatever I want for dinner on the 3rd day. So far, as of this morning, I have lost pounds 3.8 pounds
    I noticed a huge low carb following here and that you only drank water & black coffee on your fasting days. I don’t plan on staying with the MC lemonade part of it once I reach my goal weight but the 2 cups of fruit juice a day on fasting days I would like to be a staple.
    Do you think me having the sugar from the syrup or blackstrap molasses or juice poses a problem for my future success?
    It all depends upon what you’re eating overall. I don’t think whatever minuscule benefits you might get from the tiny amount of vitamins and minerals in the syrup or molasses is more than offset by the sugar.

  279. Hi again Dr. Eades –
    I wrote to you back in August and you posted a great reply, thank you. I’m still finding the whole topic of IF and this blog so interesting.
    I wanted to provide an update and ask further questions. I’ve been experimenting with various forms of IF and calorie reduction since August 2008. My goal has been and continues to be losing 5 pounds and keeping it off. I suppose I should mention that I weigh 115, and I know you’ll say that because my weight is already low, it may be hard for me to lose weight. However, I’m only 5″2″ and weighed no more than 110 for years, which felt like the best weight for me.
    Last fall after I wrote you, and also read some new information about the appropriate number of calories I should be consuming to lose weight (pretty low given my size), I adjusted my formula to further lower my average weekly caloric intake. I find it relatively easy to fast and eat very low calorie during the week, so that I can enjoy “normal” eating on the weekends. Not pigging out mind you, but enjoying some wine, bread and occasional dessert. It seemed to work – right before the holidays I finally lost those 5 pounds.
    Well I put it back on during the holidays (so much work and time to get it off, so fast to put it back on), so in January I started back up on my regimen. It’s now been nearly 8 weeks and I haven’t lost a pound. (It took about 8 weeks in the fall to lose 4 pounds).
    I re-read your comments from August and am thinking my body must be on to my routine – and maybe it won’t work as well now. But my question is this: how is what I’m doing different from the success so many people have with IF? If your body doesn’t “hang on to fat” during IF, why would mine be holding out knowing it will get “fed” on weekends? Isn’t it simply a matter of calories in and calories out? If my caloric weekly average is 1350 shouldn’t I be losing weight – it worked last fall. And, before I started this regimen, I was able to maintain 115 while eating quite a bit more calories during the week, so it just doesn’t make sense that I’m not losing now.
    I’m nearing the point of just accepting this weight for the trade off of being able to have some treats on the weekends, but I’m not quite there yet. I really want to understand the science of this – it just isn’t making sense to me.
    I am hell bent to figure this out, and come up with a healthy plan I can live with long term. If you have time for new thoughts that would be great!
    Thank you.
    It’s difficult for me to make an intelligent suggestion because I don’t know what your low-calorie diet is composed of. It makes a difference if it is a low-carb, low-calorie diet or a high-carb, low-calorie diet. If it’s the latter, I’m not surprised your having difficulty. It it’s the former, I would try to change the regimen around a little. And I might be very good for one weekend instead of easing off just to see what happens. It might be that you would drop several pounds.

  280. Dr. Eades,
    I have been following this lifestyle for a month now and love it; I am planning on making it permanent!
    The only question I had regarding my fasting state (8pm-12pm) are BCAA allowed? I like to do fasted state cardio in the mornings, but the amino acids ensure that no muscle is lost.
    Also, does my plan look okay to you?
    I then break the fast around noon with a protein shake, apple, piece of whole wheat bread (10g carbs per slice) w/ a thin layer of peanut butter for taste (maybe a teaspoon)
    I workout from 1:30-2:30 and @ 3pm I have my largest meal of the day (~700 calories) composed of mainly protein/carbs/ and only a small amount of fat. Then I have a light dinner around 8.
    Plan looks fine other than that I would opt for more fat. I wouldn’t worry about the BCAA.

  281. Just a short note… I live in Thailand. Monks around here are not supposed to eat anything after 12 noon.
    Don’t see many old, fat monks. 😉

  282. I would like to include the fact that I donated blood to my husband for an upcoming surgery. Everything was fine. What surprised me was my iron was good despite the fact that I was on my monthly. Also I was not dehydrated despite the fact that I am not very thirsty and drink very little water. I drank a little more because of the blood draw but it was not much more than my usual intake. As of this weekend I have been doing intermittent fasting for 2 years.

  283. My roommate and I researched the calorie restriction diet about a year and a half ago. It sounds wonderful, and we tried it for a few weeks, but it was so much work! tracking every bite we ate, tracking all the micro nutrients, even trying to figure out when and how much to eat. the benefits seem fabulous, but it isn’t a practical diet.
    then a few months ago, my brother did EAT-STOP-EAT, a diet ebook published by a nutritionist. he lost 12 lbs over a few weeks and said it was really easy, but he only fasted ONCE A WEEK for 24 hours (the same thing dinner to dinner). I was looking for something a bit more rigorous – i actually need to lose a bit more than 20lbs. I think you and your friend’s plan is exactly what I’m looking for 🙂 Thanks so much, I’m going to start tomorrow!!! I’ll let you know how it goes and if i lose the weight (and how quickly).

  284. Hi Dr. E:
    I absolutely love the idea of the IF; it is right up my alley and seems to be very sound! However, my lifestyle doesn’t allow for an exact program of eating times due to “required” eating schedule. I was wondering if you think the follow system would work:
    Sunday: Eat as per normal
    Monday: Fast (first 24 hour fast)
    Tuesday: Eat as per normal until 4:30 PM
    Wednesday: East as per normal AFTER 4:30 PM (completion of 2nd 24 hour fast)
    Thursday: Fast (3rd 24 hour fast)
    Friday: Eat as per normal after 4:30 PM (I’m guaranteed to eat a LOT on Friday nights, so I extended the previous fast to cover it)
    Saturday: Eat as per normal.
    So it has 3 24 hour fasts in a week, but a 48 hour periods without fasting. Should this still work?
    It should. Best thing to do is give it a try to see how it works for you.

  285. Just to leave an interesting comment. I’m an adult with ADHD treated with Adderall which kills the appetite while the medication is in effect. For the past 2 years or so I’ve been on a very erratic work schedule which at times leave me on diet coke for 36 hours even when I do get 4-6 hours of sleep.
    I haven’t caught a cold in these past 2-years and just when I was worried that my health was being jeoprdized with my irregular eating habit. I discovered the intriguing information about intermittent fasting and and this blog. Which leaves me with an interesting question.
    Q: How does the effect of amphetamine work with the fasting?
    I don’t know about how amphetamines would work with IF; I haven’t had any hands-on experience with them.

  286. hello dr. eades!
    after reading your updated ideas on IFing, i thought i would add that, after IFing for months on end (six to date), im finding it a wonderful lifestyle. diet plan not so much. i’ve shrunk my eating window from 4-6hr to 1-3hrs most weekdays, and incorporated longer, more carb based cheats on the weekends. ive lost several pant sizes and continue to lose body fat, but not as fast now. it feels to me, that longterm IFing with no overt calorie restriction has improved my health and energy levels greatly and is changing the shape of my body consistently on a week to week basis. but dreams of drastic reduction is short amounts of time have not happened longterm for me. i just love to eat. im doing 5oish carbs a night , so ive adopted the more low carb approach. thanks for the your blog as it intially helped motivate me in many ways to get started. my continued experiment is being documented at cheers!!
    I’m glad to hear you’re doing so well. And I’m glad my blog was a source of motivation. Keep it up.

  287. You said in a previous post, “You don’t force gluconeogenesis by eating protein. You only undergo gluconeogenesis if your blood sugar levels start to drop too low.” Yet, I experience a much higher than usual rise in my BG when I eat much more meat than is typical for me on my LC diet — I monitor my BG regularly as diabetes runs in my family. I take no medications of any sort and have no health problems.
    I typically eat 1 to 4 oz. meat or other protein per meal or sometimes a snack. My pre-meal is usually in the 80s and my post can be up to 105. However, if I eat much more than 6 oz meat at a meal, it will easily be 115. This is one problem I am trying to work out while doing the IF and even doing the Protein Power by the way. With the IF, I know I won’t be able to eat all I want when the fast is over because it will raise my BG too high even if it is LC. By the way, I am 58, female, 5’3″, 130 lbs, very small framed and need to lose about 20 pounds from my middle mostly. I am going to start the Slow Burn if I can work all this out and do it all in a healthy fashion.
    Please explain why this statement is untrue in my situation. Do diabetes or Insulin Resistance related factors cause gluconeogenesis prematurely when a certain amount of meat is eaten? It’s only when I eat well over 5 oz. that my BG rises too high. What can I do to get enough protein without causing this reaction? How can I get enough protein if I do the IF?
    I don’t think a blood sugar post meal of 115 is all that high. Protein will run blood sugar up a little, especially if it is consumed with some carbs. But the elevation in your case isn’t out of the ordinary. I wouldn’t worry about it.
    I’ll do a long post on protein and blood sugar in due course. It seems to be a topic that has a lot of interest.

  288. Hi Dr. Eades,
    Fantastic study! I am a personal trainer and so I am always experimenting on myself with various things, just to get a feel and understand different things. I am currently trying my most extreme experiment which is water fasting for five days (I’m done tomorrow). I have been reading all i can about fasting and really like the idea of intermittent fasting, that will be my next experiment, once my body recovers from this food drought I put myself through.
    Looking back I realize I did this a lot of IF when I was younger, some days not eating much if anything other days eating normally and enjoyed fantastic health. It wasn’t until I began to worry about weight and what I was eating, how often each day etc that I begin to struggle to keep that level of health–interesting!
    I will let you know what I discover, I am going to try fasting 24 hrs. once a week for the next month (5pm til 5pm next day) and then once I feel steady after this prolonged fast I’m currently on. I’ll try it two times a week. Do you want me to keep you posted? This is incredibly interesting. I’m still young and healthy so I think this should be fun.

  289. I am very interesting in IFing. I have been following CAD. I have noticed that I am not hungry for the 2 LC meals, only the RM at dinner time. Dr. Rachael Heller only ate one meal per day before the book was written and that is how she lost over 100 lbs. Later when the Hellers’ wrote the Carbohydrates Addicts Diet book, they found that they could eat the LC meals too. The diet is based on the insulin released for the first 2 LC meals. Because of the small amount of insulin released on the 2 LC meals, insulin is released in a small amount at the Reward Meal (written now that it should be balanced but you are allowed carbs) within the first 60 minutes. I do have 2 questions. If this is true, will only having the RM make me more insulin resistant? Should I have the same effect of low amounts of insulin release at the RM? or is it just less calories? My second question is I have a trainer that works me out now 3 times per week and I don’t eat until everyday at 8 pm, will no food give me less energy or hurt me at all in my workouts? Thank you very much for all the information that I have read so far. I really have no appetite during the day now and really enjoy regular amounts of food at dinner and have no cravings for junky food.
    I think it is untrue that if insulin is low during the day, the RM won’t provoke a large insulin response. It has to. The body has to deal with the sugar contained in the meal. If it doesn’t the hugely elevated blood sugar levels would be harmful and create enormous problems on their own. So, yes, the RM does provoke an insulin response large enough to deal with the carbs eaten. And a large insulin response can indeed worsen insulin resistance in one already afflicted with the problem.
    I don’t think the food intake schedule will affect your workouts in a negative way.

  290. Google EAT STOP EAT by Brad Pilon. 1 or 2 24hr fasts per week create enough of a caloric deficit for weight loss and you get all the other benefits of fasting as well. Make sure you keep working, preserve your lean muscle and watch the fat disappear.

  291. I have really enjoyed reading all these post.
    I would like to see some studies on how IF and a ketogenic diet (what I am doing) will work together. Like some here I have a problem with the whole IF and eat 200gms of carbs at a time, common sense says that it is WORSE, all the poison at one time. I would think one is asking for messed up metabolic profile.
    I am getting blood work at the end of august, well see.

  292. Keto Jim, I keep my diet truly ketogenic. I rarely eat more than 20 grams of carbs a day. Albeit there are some days when I consume more but it is rare. If you noticed any of my posts here, I also do a 20 hour fast with a 4 hour eating window. However, I sometimes eat only once a day. If you are doing a keto-type diet it is more important to eat more fats since that is where ketones come from and that is your energy source. My metabolism has responded quite well to the combination of low carbing and IF. To me, perhaps it is because I have done this for so long, but it is common sense that the metabolism would improve this way. Afterall, it has to work harder, therefore it gets stronger and it becomes more efficient at burning fat and calories. Just my way of thinking the whole picture. I had a check up and blood work in June and I did quite well. The only thing I find odd is my iron levels were low but my energy was high. Is it possible that my body doesn’t need as much iron/oxygen? I am taking supplements until I visit my doctor again. But I wonder if they are really necessary. I look forward to your comments Dr. Eades
    I don’t know how low is low in your case, but many women who are pre-menopausal run chronically low iron levels. Some believe that is the reason pre-menopausal women are protected from heart disease.

  293. Interesting Dr. Eades. I just noticed that you had commented here . My hgb value was 10.9. Don’t know if that is enough info.
    I’m not sure without going through a bunch of comments. You’ll have to enlighten me a little more.

  294. I’m really interested in the idea of intermittent fasting, and I was just wondering, is it okay to drink tea on the fasting days? I have a ginger lemon tea and a blueberry tea and I figured with the ginger lemon at the very least, it would help the detox process. It states that the tea is 0 calories as well, but I was just wondering if it could interfere with the fasting process at all. As a note it is also caffeine free, not sure if that makes a difference. Thanks so much for this interesting article and information! I think I might actually put my person results in the offtopic section of my webpage over at if anyone is interested. Thanks again and take care!

  295. It’s really weird; I just started fasting (I’m in my 2nd week) on Monday’s, Wednesday, and Friday’s. I had no idea that there were others who actually do this as a way of life until I started finding reasons why I shouldn’t be doing this. I started doing this because for the last 3.5 years I have been working out almost daily and haven’t lost any weight. I would run 6 days per week, 3-5 miles and I typically work out 1.5 to 2 hours on the days I work out and they’re always tough workouts. I have always thought that working out as hard I have was actually causing me to keep my extra weight on. My problem is with food. I am a sugar addict. I love sweets, not starchy food like pasta, breads, potatoes; just homemade baked goods. If you take out the daily dose of sweets, I eat a very healthy diet, closer to a stone age type diet. So far I have to say that fasting intermittently seems to be working for me. I feel like I have much better mental clarity, I’m not even thinking about baking cookies or eating ice cream, my appetite seems more controllable, my belly is flattening, and I have energy. I am not working out; I think I’m going to concentrate on my eating habits and when I get to my desired weight, then I will exercise for maintenance.
    The only problem I am experiencing is I feel constantly dehydrated. Would that be related to fasting?

  296. Hello,
    I am a female 5’4 around 140 size 6. I carry my weight well I assume because I exercise regularly and eat fairly healthy. I would however like to lose about 10 lbs of fat. I have a long history with weight issues, mostly psychological. I think I am very near whatever my body thinks is its ‘set weight” because it is very difficult for me to lose weight. Except when I was starving myself, which I don’t want ever to do again. But I’m becoming very anxious about wanting to lose this weight. My question is, do you think intermittent fasting would benefit me if I am close to a healthy/goal weight? Or does it seem to work best with people with significant weight to lose?
    Also, for the past two months are so I’ve been eating low carb, which I like as a lifestyle. I don’t know if I have actually lost weight, no scale, but I don’t think I’ve gained weight. See for a while after I wasn’t eating enough I was gaining weight when I began eating enough. This seemed to stop with low carb.
    Thank you, very informative blog by the way.

  297. I fast Mondays, Wednesdays, and Fridays. Sundays I eat light. Why am I so thirsty all the time? I feel dehydrated no matter how much I drink water.

  298. Hi Dr.
    My first post here 🙂 Just found your website. I read your first book many years ago (and wish that I had stuck with your recommendations back then.)
    Earlier this week, Monday, for the Yom Kippur holiday, I fasted. I thought about fasting in general, and about IF, and found this blog post while doing some research. I was sold. I did a 8pm to 8pm again on Weds and it went really well. Anyways, later on, as I continued my research, I found that you wrote a second post saying that the IF thing wasn’t all that great after all and it seemed that your recommendation had changed. I read it on Tim Ferriss’s blog, here: .
    Anyways, it would have been really nice to see part 2 of your post together with part one. I think it’d be really nice if this post linked over to part 2, which does provide a significantly different view in regards to the subject matter.
    Thank’s for all the work you do on your site, by the way. You’ve got a new reader. I’m saving for one of those cooking contraptions, too. Would like to buy one for my gf for xmas, she’s a great cook & will love that thing.

  299. I just started a regimen and wonder if any research has changed since the original
    post. The idea I am using comes from the leangains website – eating in an 8 hour window, from
    noon to 8 each day and fasting 16 hours. I have heard things like 15-18 hours of fasting provides all the same benefits as alternate day. I’ve also gotten a bunch of info from
    Robb Wolf and the Crossfit community. I’m concerned with health and performance and am interested to know if anything has come up about 16 hours vs. 20 hours vs. 24 hours etc.

  300. Hi Dr. Eades,
    I started the IF regime 4 weeks ago – I stop eating one day at 6pm and start eating again 24 hours later at 6pm throughout the week. I was prone before to getting low blood sugar swings – feeling light-headed, sweating and shaking – at certain times of the day – and suffering too with digestive problems. These have all disappeared. I do tend to over-eat at the end of each fast – the consequence of this is my belly feels like it has a brick inside it – but this soon passes. During the first 2 weeks I found it impossible on the fasting days to drink black coffee so I was cheating and drinking coffee with a small amount of milk. I have now started leaving out the milk and feel like I’m achieving more. My stomach is now totally flat and my eating habits are more under control. I have learnt that most of my eating previously was based on eating whatever and whenever I liked, often to counter-act stress or just something to do. The amount of times I walked automatically towards the fridge door or the bread bin was quite scary. Now I have more self’-control. On the mornings of my fast days I have boundless energy , especially when I do my exercises. Is it normal to ‘go off’ alcohol ? I have developed a lack of taste for alcohol – it’s like a physical aversion. And that’s going from drinking a bottle of wine most nights. Is this common to go off alcohol ?

  301. Hi doc,
    Quick question on peri-workout nutrition. I generally train from 11am-12pm. 35 mins prior to lifting i take a preworkout supplement containing about 100 cals, almost all comming from carbs. Post workout i drink 16 oz of chocolate milk. Would this peri-workout nutrition be permissable during the fast? As a side note I am not doing 24 hour fasts. I do 16/8. I generally fast from midnight until 4pm, with the exception of the epri-workout nutrition. Is this advisable or am I messing up the benefits of fasting? thank you

  302. Your blog post had a lot of good information. It also mentions some good studies to back up what you are saying. Americans are eating more than ever before and obesity and type 2 diabetes are at epidemic proportions.

  303. Doc,
    Thanks so much for you info on IF. I am doing crossfit and eating lacto paleo. I am doing IF every other day with a fast window of 12-15 hours. I am struggling with headaches. I am not asking for your medical advice, but is this common with fasting and what is a suggestion to try?
    Could many things, the vast majority of which are not serious. I don’t know your coffee-drinking situation, but maybe caffeine withdrawal during the fasting time could be a cause. It’s difficult for me to comment without knowing a lot more. If the headaches are serious and continue, you should be checked.

  304. Dear Dr. Mike,
    I read your post with much interest.
    I would like to give the IF a go but am concerned about weight loss. I’m 5’9″ and weigh around 143 lbs.. I have a very active-oriented job – on the move a lot – and I work out quite vigorously 4 times per week. My appetite is often voracious! What would you suggest?
    The other thing, I take a fair amount of fish oil (Carlson’s Med Omega) on a daily basis along with pancreatic enzymes, curcumin, and green tea (in capsules). Given the calorie issue on fast days, I presume that it would be best to forego the fish oil on during fasting days.
    What would you suggest? Again, my primary hesitation is weight loss. One thought would be to fast every 3rd or 4th day.

  305. addressing Bob’s comments:
    I’ve IF-ed since May 2003, doing a 24-hour fast that commences every other day routine for over five years. It’s gone well and I maintain my weight without any problem. I have two exceptions to the no-calorie routine: a glass of red wine and the fish oil. I doubt that any benefits would vanish with these two “indulgences” — red wine contains resveratrol that activates sirtuin activity and fish oil omega 3s seem most important.
    I typically exercise vigorously one hour/day. I also eat often voraciously on eating days “there is no spice like appetite”
    I also take a resveratrol tablet (for about six months now)
    I’m 71 now, have to watch my salt and take a diuretic for high blood pressure issues, have some mild osteoarthritis, but otherwise am very alert, energetic, and healthy.
    Of course we don’t know what these personal experiments will have as outcomes, but I doubt much cancer. I sense that any IF is better than none and that the most one can tolerate is best. I like my present regime and the social connections so often a bar to IF are all accommodated in my family. I do have a policy of “sociality trumps schedule” so rarely I will eat at 23 or 23 and a half hours if the situation would be best doing that.
    Have contributed to Dr. Eades blog before. Good to reread his 2006 statement.

    1. I read this entry a couple of years ago in researching low carb diets and, though intrigued by the idea, didn’t think I possessed the temperance to hang with it. That all changed this year when I participated in a 21 day juice fast with my wife. Beginning in early January, my wife and I ate no solid foods, but we did allow ourselves to have a few protein shakes every now and then, along with some pureed vegetable soups.
      Long story–short, I ended up losing 17 lbs, but that’s not the best part. I have very stubborn hypertension. It’s hereditary and started when I was 18 years old. Although I was 165 lbs and running 4 miles a day, my BP ran 160/112 at times. This has persisted throughout my life, and it only succumbs to quite strong medicine. My doctor has changed my meds a number of times trying to get it under control, especially now that I’m 33 and overweight. Well, the fast did what my medicines have been unable to do.
      About a week and a half into the fast, my wife suggested that I check my BP. I told her that it was unlikely to be elevated, seeing that we hadn’t been gorging ourselves. She wisely responded, “Well, what if it’s too low for you to be taking your medicine?” That, folks, is called a Woman’s intuition, the Hand of God, or whatever other form of divine intervention that you want to ascribe to it. My BP was at 90/65 with a pulse rate of 65. If I had taken my meds… No telling.
      Anyway, I kept checking my BP throughout the fast to make sure that it wasn’t a fluke, and sure enough, it remained well below 120/80. With this new-found temperance–and encouraged by my terrific BP–I decided to break the fast by starting a regimen of IF, which led me back to this blog post.
      I was curious as to whether my BP and HR would stay at my fasting levels after I started adding food back into the equation. Sure enough, a week into IF, my BP is averaging a very safe 110/75 and my HR barely gets above 72. I haven’t taken BP meds in over three weeks now, and it’s the best it’s ever been. I plan to continue to monitor it closely, especially since I’m off my meds, but in my limited experience, IF is a miracle. I’m so thankful that I read Dr. Eades’s post!

      1. And I’m thankful for your taking the time to relate your history. Based on my experience, I wouldn’t have predicted such a dramatic improvement so quickly. I’m delighted to hear that you are so much improved. Keep it up and keep us posted.

  306. Hmm, I’m not quite sure about this. I used to skip meals and by dinner I was ravenous and would pig out, then experience what I think was reactive hypoglycemia. I believe I experienced low blood sugar throughout the day as well and would CRAVE carbs to the point that I would binge and then purge. Yes, I developed an eating disorder, not to mention the fact I was constantly thinking about food. A doctor told me I needed to eat protein every 3 hours. Moreover, I ultimately wasn’t eating enough calories, which made my body think it was starving and shut down my t4 to t3 conversion. Following the doctor’s advice worked and believe me, I was VERY hesitant to eat that much food! But it worked. All my food cravings disappeared along with my eating disorder and my unhealthy obsession with food. I am not sure IF can work for everyone. Any thoughts greatly appreciated!

    1. There is a wrong way and a right way to do IF in my opinion. I would never fast if I had not had a hearty pre-fast meal, first. I enjoy eating alot of low carb/protein/ with added fats such as butter and coconut oil. I do indeed pig-out if I have the need.This kind of meal makes it easy for me to got 20-22 hours in a fasted satate. I also consume fats during my fast by adding coconut oil or MCT oil to my coffee. Many people don’t consider this as fasting but when you consider that fasting is ketogenic then I conclude that fats are a plus not a negative. My food is nutritious I rarely ever eat anything “bad” . No cakes, cookies, breads, potatoes. I have had blood work done and it is exemplary.
      Whenever I hear someone say that they cannot do IF, I wonder if they do it like me. I think not.

      1. I have noticed that you have referred to MCT several times…I am at a loss to figure out what this is…could you explain? Thanks

          1. Thank you so much for such a quick answer to the MCT question…
            This next question is a little off the subject of IF but, I have your Comfort Food Cookbook and since I puchased it I have found that I cannot tolerate Soy (it makes me have arthritis like symptoms and being Hypothyroid I am not supposed to have it for that reason either) Is there something that can be used in the recipes to take the place of Soy?

  307. I do 24 hour fasts every other day x 5 years at least and do not experience ketosis (though I do drink a glass of wine and consume salmon oil capsules as my sole calories). I believe the liver has a 24 hour supply of potential glucose in the form of easily mobilized glycogen (that contrasts to muscle glycogen that’s less easily mobilized). When in my early phases prior to a 24 hour fast commenced every other day, I fasted from dinner offset through the whole next day to breakfast on day 3. My wife then did notice ketone bodies on my breath (I did wine and oil capsules for omega 3s back then too). So I tend to believe (for me) that the liver has that 24 hour supply.

  308. I have been reading a lot on the Internet about IF and decided to give it a try. I had just had blood work done so I know where I am starting from and will know if this is working for lowering cholesterol etc. I have been on this plan for a week doing 24 hour fast three days a week. I have lost 6 pounds so far. I have for years done low-carb only to end up causing a kidney stone (and not losing much weight at all), so cannot do that anymore. So I have switched to more veggies, fruit and low-fat proteins. I have high hopes for IF…my main reason for doing this is weight loss and to see if the health claims are for real!

      1. Well, I have been just about a month and the bad news is that I haven’t lost another pound. So, I am going off the IF and going to try and figure out just what I need to do. I have found that being Hypothyroid makes me very resistant to weight loss…eating or not eating….!

        1. I have not been able to lose weight quickly on IF. I averaged about 7-12 lbs loss/year and I do IF everyday.

          1. I meant to also say, that 4 weeks isn’t long enough to tell if IF is working or not. Personally, I would give it a year…serisouly to conclude if it works or not.

          2. Thanks for the encouragement…I guess I get discouraged easily…I have tried so many things and over the years the weight keeps going up…I will give it another try…especially if it is good for my health. I know that fasting gives the body a chance to heal and ‘clean’ itself so just that makes it worth it I guess. Thanks again!

          3. I am indeed healthier now than I was 3 years ago. It is easy to stick to eating healthy foods without cheating. I think that is because after developing the habit of eating within a scheduled window, you don’t want to waste that time eating cookies and/or chips. I make healthier eating decisions. I am by-no-means an athlete but I walk everyday while I am fasting. Fasting enhances the success of excercise.
            Gloria, I had to work up to fasting. I didn’t just wake up and said, ‘I’m going to start fasting”. I began by eating breakfast and hour later each day. For example: If I eat breakfast one day at, 6:00 AM, after a few days, breakfast would be at 7:00 AM then 8:00 etc. I did this progressively until I was able to go until 3:00 PM before breaking my fast. That alone, took a month. Most importantly I feast when I break my fast. I enjoy large healthy meals without feeling the need to watch my portions. One thing I learned when I was considering using fasting was this isn’t about reducing calories, it is about reducing meal frequencies. Fasting allows the gut to complete the job of digestion and gives it time to rest.
            What I liked about that was I could feel myself getting stronger physically and mentally.

  309. Hi Dr. Eades,
    I haven’t read this entire thread (it’s very long!), but I see you’re still responding to posts here so I thought I’d ask my question:
    When you describe the eating pattern do you eat supper on the full eating days or are you eating breakfast lunch one day, and only dinner the next?
    I.e. is the pattern:
    day one eat: breakfast lunch dinner
    day two eat: dinner
    with the last bite of food say 6:00pm day one and the next bite of food 6:00 pm day two (so a 24 hour period between bites)
    or is it:
    day one eat: breakfast lunch
    day two eat: dinner
    with the last bite being at lunch on day one and the next bite being dinner on day two (so around 28 hours between bites of food for the fasting period)
    Also, I’ve read comments elsewhere (in the forum) that you are not convinced there is any health benefit to the IF eating pattern … is that true? I’m still interested in trying it just because it seems like, if tolerable, it would be a good way to reduce my overall caloric intake (there’s a guy pushing a diet book based around that scheme).
    Thanks for any info you can provide.

    1. Our regimen when we IF is the second of the two you described. We do it a little differently, however. We ate breakfast and usually a late lunch (circa 3-4 PM) on day one, then didn’t eat again until about 6 PM on day two.
      I’ve been back and forth on the IF issue. The more data that comes in – especially human data – the more I’m convinced it is a healthful way to live. Especially if what you want to eat is high-carb stuff. If you follow a good low-carb diet rigorously, you probably won’t gain as much of an advantage with an IF as you would otherwise.

      1. I was thinking this for an IF schedule with a lean towards low-carb dieting: what if you eat breakfast, then a late lunch/early dinner (at a time maybe in between you would eat the normal lunch and dinner), and then the next day either ate breakfast like normal or eat lunch at a more normal time?
        Example A
        Day 1: Breakfast, late lunch/early dinner (same concept, just depends on how you’d phrase it), sleep
        Day 2: Breakfast, lunch, dinner, sleep (i.e., a normal day)
        Example B
        Day 1: Breakfast, late lunch, sleep
        Day 2: Normal-timed lunch, dinner, sleep
        Day 3: Normal day
        Which example would you lean more towards doing as a low-card eater doing IF?
        Thank you!

  310. Sorry Mike, I made a comment about the Warrior Diet/IF parallel and how people weren’t giving credit to Ori Hofmekler in a fair way, since IF is on the back essentially of the Warrior Diet putting the fasting/eating method into the more public mindset in the fitness/health community, but now see that this blog activity was way back in 2006…

  311. FInally, I am four lbs away from my goal weight. I must say, however, that I had been stuck for the longest time at 148 lbs.I began losing again early January, after adding vitamin D 3 to my diet. I am now at 139 lbs and I continue to do low carb intermittent fasting. My dietary lifestyle has contributed to my healthy regimen and I intend to keep it way up.

  312. Hi, my IF pattern is really flexible. I target for one meal a day and that works fine for me. Hence my fasting period is sometimes longer than 24 hours and sometimes shorter. On average, I do the 24-hour fasting three to four times a week. It’s been my 5th year of IF.

  313. Hello,
    I just got the results of recent blood work. My glucose level has gone up from 95 mg/dL in November last year to 103 on March 3rd 2010. It was 87 in 2008. I’m getting concerned given my diet, which may not be good enough after all.
    I do eat oatmeal frequently for breakfast (3 times per week) and eat a couple slices of Manna Bread from Julian Bakery a day. My whey powder has stevia in it. Other that those things, my diet consists of vegetables, a few blueberries, fish, and eggs. My Omega 3 to 6 ratio is excellent.
    Now, my fasting insulin level (through Quest Diagnostics) came back < 2.
    I am 56 years old and concerned that I may have early stage diabetes 1.
    I was advised by a nutritional researcher against IF due to my weight. I'm 5' 9" and weigh about 142 pounds. I have resumed exercising regularly after a break of about a month due to family issues that needed addressing.
    Any insights would be greatly appreciated.

    1. Both the oatmeal and the bread will drive blood sugars up. I’m not sure if that’s causing your problem or not because I don’t have all the specifics of your situation. I don’t think your body size precludes you from following an IF as long as you consume plenty of good quality calories during the time you do eat.

  314. Hi Mike.
    This is so interesting to me. I’m about 5’7″ and 135 pounds. I am certainly not claiming to be obese at all but would love to get a little leaner. I’m wondering if this is my answer? I work out daily (running 4 miles on cardio days and weights every other day) but haven’t been able to drop about the 8 pounds I’d like to. I’ve been told I’m not eating enough but then my husband told me one of his friends who is a trainer does IF and swears by it. This is the best trail of posts I’ve found so I’m very interested to try this out. I’m in great health (I have mandatory blood work done every year for my insurance coverage) so I’m not concerned with it being detrimental to my body.
    My question is…I assume this needs to be a lifestyle change. Is it possible to reprogram myself permanently?

  315. Bob, I am pre-diabetic. One thing that I have learned is that IFers tend to have higher FBG levels but their levesl throughout the day tend to be quite normal. I avoid foods that are high in carbohydrates namely oratmeal and bread. my doctor’s advise is to watch my carbs. He is aware that I fast on a daily basis.
    Also, I began taking some good vitamin D supplements and I was surprised at how much my glucose levels went down.
    They continue to slip into the normal range. I monitor my blood glucose on a daily basis. I don’t waste time eating poor quality food. I always , always eat healthy low carb meals. I also walk for 40 minutes to an hour daily.
    I hope this is helpful.

    1. I would like to post this link on Lee Shurrie’s blog. He discusses how he defeated his Type 2 diabetes thru exercise, vitamin D and fasting. He also includes the addition of coconut oil to his diet, if I am not mistaken. Reading about him reminds me of my experiences.

  316. I experimented with IM about a year ago as a way to lose weight. I was able to lose about 2 lbs a week by fasting 3 times/week. Each fast was pretty much as you described – about 23 hours between meals. I started a new regime earlier this week, one that is much more restrictive. I don’t eat Monday, Wednesday or Friday. I never eat breakfast, never have. So my fasts are about 40 hrs in length. I have lost about 7 lbs this week. I feel great. I don’t feel especially hungry during the fast and my energy levels are fine. I plan to lose almost 50 lbs this way. I have no portion control… I find that it is much easier for me to either eat or not eat. Controlling how much I eat is difficult. Once my weight is down, I’ll switch to one day of fasting per week.

  317. one of the posts I recently read here (don’t now see it above) said that soy should not be consumed if one is hypothyroid. I am hypothyroid and hadn’t known this. Dr. Eades or others, what’s the story on that? Why not soy in hypothyroidism. I occasionally eat soy and had thought tofu a good food.

    1. Soy is a goiterogen or goiter-causing substance because it binds with dietary iodine, impairing the body’s ability to absorb it.

  318. thanks! I’d have to take plenty of iodine to counter it (as in supplements to salt etc): a dietary counter to that tendency.

  319. Hi!
    Almost every other website says that our body goes into “starvation mode” if we eat only once a day. If I eat only one meal a day (so fasting for about 20 hrs), would my metabolism slow down? There is so much contradictory information everywhere that I don’t know what to do!
    Also, I live in South Korea where every meal is with white rice or noodles….would I still be able to reap the benefits and lose weight even with eating carbs all the time?

    1. 1. No, your metabolism won’t slow down.
      2. It doesn’t matter that much what you eat when you are fasting and rice isn’t the worst of carbs. Noodles I would avoid though.
      3. You need to keep overall calorie restriction to lose weight, regardless of how you eat. It’s easier to do this when you fast, but just keep that in mind.

  320. Hi,
    I haven’t read the entire thread but thought I’d add my comments and read later. I have been engaged in various forms of IF for 31 years ranging form long fasts to fasting one day a week. I started when I was about 19 and I am now 50. In the late 70’s and early 80’s my husband and I did some radical fasting- 30 days on juices. Neither of us were the least bit overweight, we did it to cleanse.
    At this point I am pretty much known for my impeccable health and youthful appearance and demeanor. I feel great and almost never tire. No gray hair. No wrinkles. No medications. I’m at a healthy weight after having 5 kids. People say to me ” I knew a lady 20 years ago that sold baskets and flowers, was that your mother? Can’t be you because you look the same.”
    Yes I have a healthy lifestyle and good genes. I live in the country, have a peaceful happy life and my gardens overflow with unlimited organic produce 10 months a year. I’ve been a vegetarian for 30 years. But I have wonder if fasting intermittently for 3 decades is a factor in my good health.

  321. Dear Dr Eades,
    About 5 years ago I lost 70 lbs. by eating one small meal a day. I had an extreme amount of weight to lose. in 2005 I had 2 mini strokes that were attributed to Atrial Fibrillation. I have been cardio verted twice,the heart meds no longer keep me in rythem, so my heartbeat remains irregular. I have had a cardiac catherization with no results as to what is causing my A Fib. BTW I also regained the weight plus 10 additional LBS.
    What are your thoughts regarding IF in relation to A Fib ?
    I have been eating one meal a day for the past week and I feel great. Hungry in the AM but with a glass of water it disappears, I have my meal between noon and 2 o’clock and it is LC …no grains. I have more energy,and my joint pains have disappeared. I also fill up fast when I eat and have lost my craving for sugar. I have a considerable amt. of wt. to lose >125 lbs. Have dropped 4 lbs. this past week which makes me feel I am going in the right direction.

  322. Hi Mike
    I love the idea of the IF program, although i don’t really suffer from to many health problems my biggest concern is my weight, i weigh about 215lb I have been this heavy for years and have been tring so many things but i still feld. If the IF program can help me loose some weight I will be extreamly happy. So my question is, do you think the program will help me loose weight and start me out on the right track.
    Thanks Kai

  323. Hi,
    I’m trying intermittent fasting because I feel so frustrated with my weight right now. I gained about 100 lbs. in less than a year in 2008-2009 due to a terrible combo of psychiatric drugs which gave me a thyroid problem and really exacerbated the horrible varicose veins in my legs. As soon as I began weaning off those drugs, I got so much better mentally and got a second opinion and counseling. Great, I’d wasted 2 years seeing a psychiatrist for a condition I didn’t even have.
    Well, I was feeling great mentally, but was a physical wreck. I was able to stop the weight gain, but after a year of having 1 bowl of mini wheats for breakfast and lunch and watching my dinners and cutting back almost entirely on baking (which I love), my weight just sat there and then I even gained 10 lbs after 2 car trips that really made my leg swell up. I can’t even get my doctor to call me back to talk about IF, but I’m doing it.

  324. Thanks for your continued commitment in giving us valuable information on staying healthy and fit. I always enjoy your posts, and appreciate your adventurousness in trying new things. You stay so well informed by reading all the medical data. That helps so much. Again, thank you.

  325. I have been doing intermittent fasting for 2 years straight the way Brad Pilon recommends in the book “Eat Stop Eat”.
    Here is a quick outline:
    * eat normal 5 days per week
    * fast 2 times per week until dinner
    * for that dinner meal, eat a normal size dinner (not a day’s worth of calories)
    What I have found is that this is a way to reduce your weekly total calories and can create a nice weekly calorie deficit.
    There are other nice advantages as fasting has shown to boost HGH, but to me the whole calorie deficit created is what really makes the difference.
    It is simply a great way to eat less, without feeling like you are dieting hard most of the time. Once you get used to fasting it is really easy as well.
    Solid Topic,
    -George D

  326. Hi there,
    Thanks for the excellent read. I have been most interested in the subject and tried it off and on for a few days over the past 6 months. I finally realized it is a system that must be implemented whole-heartedly in order to maximize results and benefits. Thus I started the 24 hour on, 24 hour off, program last week. Lost 7.5 lbs in one week, I understand that much of that is water loss, understanding that the caloric restrictions that would imply. However, I adhere to teh 24 hour fast, combining that with a full 1 hour workout every morning that incorporates heavy lifting and high interval cardio within the rest periods of my excercise. This maximizes my workout efficiency. I have not seemed to lose any musce-mass, but have managed to lose inches. I hope to lose some 40 lbs to get to 200 lbs. I am a 43 year old male, quite muscular. I have noted a reduced appetite and am working on lowering my blood pressure. I’ve implemented a supplementation program to minimize inflamation including axtazanthin, garlic caps, fish oil, multivitamin and a morning shake on my eating mornings composed of almond milk, flax seed, frozen berries, protein whey.
    I wonder, have you had a chance to post or read any further breakthrough research on the subject of IF. I scan the net regularly, but have not found anything relatively new on the subject. Also, at which point in the fast would a body go into ketosis, readings vary, I believe my utilization of a high interval training session in mornings would aid me on fast days to use up my glycogen stores more quickly.
    Thank you for your post and your time – I shall keep you updated.

  327. Such an timely article. It is extraordinary how you distill your point and make it effortless to understand! Thanks!

  328. thanks for a great read. I have tried IF for the last 4 or so months, moslty grazing on fruit (a couple of apples and bananas, almonds) through the day and then eating a couple of big meals at nite. Based around what I first read about the warrior diet.
    My questions is this, do all the people on here who IF this way still eat small amounts of food during the day? I really find it hard to go all day with out eating a single thing (still drink water obviously). I know it is possible but man I get really hungry!!
    Also I’m just beggining to do strength training 4 mornings a week after nearly a years break, so I like to have a couple of eggs straight after for breakfast. I’ve always been told to eat good protein immediatly after training. Would it be wise to lift heavey and then fast the rest of the day and then eat a few large meals at night?
    Any feed back would be helpfull. Thanks guys. jb
    ps. I might go back now and read the rest of the 350 odd post 🙂

  329. well i have a few questions .
    i am on hydrecortisone tablets…after a pituatery opperation..if i go on the if fast how will it affect my cortisol levels…..
    I am not surprised at what u say about the if fasting i am a Muslim and we are supposed to fast…and the Quran states time and time again ….if only u knew how good fasting is for you…you and your studies are only now confirming. what the Quran teaches us…1400 years the book…it also tells us to.. eat to hungry… and NOTeat to full.
    which is hard to do…just one of the miracles and proof 1 God Allah swt and the messenger pbuh…how would they know this so many years ago.. thank you for reading…
    i would like to fast …any advice appreciated

  330. Dr. Eades, I have been on an extremely low carb diet for 18 mths.Not a single cheat.When I say low carb, I mean incidentals like eggs,occ single olive or a few jalepeno peppers.My body has transformed from a flabby, obese 260 lbs to a muscular 190 lbs.I am nearly 6’2″, a man, age 55.I have recently begun intermittent fasting.Going 24 hrs on water,black coffee with minimal hunger.Trying to do at least one fast a week.The results are a decreasing waist size.34 is now loose.I was wearing a 42 under by lap over belly.I love this way of eating.Got interested after reading good calories, bad calories.I want to be as healthy in my golden years as possible.I truely believe that I have found a way.Enjoy reading information from. sincerely, Phil Hogue

  331. The world’s oldest man, 114-year-old Breuning may have accidentally practiced intermittent fasting for the last 35 years. He eats breakfast and lunch but no dinner. That leaves ~19 hours of intermittent fasting, not that different from 24 hours of intermittent fasting in the research papers. Also his comment that he felt much better right away after starting this habit is telling. One might have assumed that he would have felt worse right away until he got used to missing dinner.
    A great advantage of intermittent fasting is that it is eminently doable for the average person as evidenced by Breuning himself. All you have to do is skip dinner. And that would be a time saver too.
    “As it turns out, longevity runs in much of Breuning’s
    family, although his parents died at ages 50 and 46.
    His paternal grandparents lived into their 90s, and
    three siblings lived to ages 85, 91 and 100. Another
    brother died at age 78.”
    (therefore, siblings averaged just 88 years–he is now 26 years older than this– and his parents averaged only 48 years; no information on his maternal grandparents but assume they died at 78; summing all of his first degree relatives up with proper weighting factors, Breuning should have lived to age 76)
    Did he reveal his “secrets” last year at 113?
    1) “I think you should push back from the table when you’re still hungry” (Famously long-lived Okinawans do the same thing, Hara Bachi Bu– eat until you are 80% full: )
    2) “Every day I exercise. Every morning I do all my exercises.”
    3) For the last 35 years, he has eaten just two meals per day, breakfast and lunch; he skips dinner and “feels much better for it.”
    4) No medications; a baby aspirin per day is the only pill he takes,
    5) drinks lots of water, eats lots of fruits & vegetables and has 2 1/2 cups of coffee per day. His breakfast is eggs, toast or pancakes.
    Looks pretty good for 113 and he is still completely lucid (see birthday speech URL embedded in article).

  332. Hi there!
    I really enjoyed reading this and I’m definatly going to try this out! I don’t normally eat much in a day if anything, so it isn’t going to be very difficult to change my eating habits – but I do have a question.
    On the fasting 24 hours can you not have any food at all? For example would the process still work if I ate some celery which doesn’t contain any calories? Celery is my snack of choice if I’m starving hungry on the go and I’d like to know if it’s off limits during fasts.
    Thankyou very much!

  333. I started IF without knowing what it was. I had to fast two days for a colonoscopy. Turned out to be easy the first day so I started fasting two days a week with the fast days lasting 32 hours. They are separated by one eating day. Then I get to eat 4 days before doing it again.
    After 11 weeks I am down 15 pounds but more importantly my blood pressure is down from 140/80 to 115/68! I can’t wait to get a physical next February to see what my other numbers are like.
    I like this way of eating so much that I don’t see ever changing. I get a little hungry and have had a 100-200 calorie snack a couple of times but generally It goes well and I know I can eat what I want in only a few hours in most cases.
    If there were ever a holy grail to getting fit and healthy this is it. I get lite exercise but will start walking a couple of evenings each week to juice things up a bit.
    Everything else you read is right on. More energy on fasting day. Sometimes I am amazed by it. Easy to control yourself, no tracking meals and calories. Just a great experience.

  334. I started low carbing three years ago, because I was desperate for help with chronic headaches and migraines. It has helped a lot, but has not eliminated the migraines. One thing I have figured out in the last year, is that is my head doesn’t feel too good, if I just STOP EATING until it feels better (this usually means skipping one or two meals) I can avoid taking a triptan. In the old carb days I would never have been able to do that because a drop in blood sugar was a major headache trigger.
    I would love to try a longer fast, to see if it might “cure” something in my head, but I’ve never been overweight, and I’m afraid I might lose too much weight.

  335. I have been doing intermittent fasting for several years now. You don’t really “drop” pounds on IF. As a matter of fact I recently put on a few pounds.
    My migraines stopped after doing LC but the auras remained. owever once I began doing IF, my auras also vanished. I discovered that I had a magnesium deficiency which contributed to regular run of the mill headaches. Actually I began taking magnesium instead of otc meds for my headaches which worked just as well. Later I realized that low manesium also contributed to my pre-diabetes so I began taking magnesium regularly and I have experienced healthier blood glucose levels.
    So, Kate, I would add magnesium along with IF.

  336. I came across IF several months ago and decided to give it a try. I’d lost 30 pounds previous to starting. I’ve been doing the IF way of eating for 4 solid weeks & haven’t lost an ounce. What am I doing wrong?

  337. I am a 26 year old mother of a 20 month old, and I hadn’t lost the extra weight I gained from having my son. So, I decided to try the intermittent fasting. For 5 days now, I have been drinking only water until 6 p.m. every day. At 6 p.m. I usually have a dinner consisting of a baked chicken breast with mixed greens & carrots. I find that the meal is more delicious than the junk I used to eat and it fills me up completely. The first couple of days were very difficult, but now it just seems normal. My skin has cleared up and I have already lost 8 lbs! I feel clear headed and surprisingly energized. I fully recommend this diet to anyone who needs to slim down and just feel healthier!

  338. Hi… I started IF today. It was such a difficult day, but then at 8pm I came across your post with its different IF schedule and I hurrayed and hurried off to the kitchen to fix myself a pizza. I will stop eating at 6pm tomorrow.
    I do have a question: I am curious about insulin-dependent diabetics. Do you think they’d be able to adjust their insulin regimen to fit around IF? If they don’t snack with every insulin shot they’ll get hypoglycaemia… so can they go completely without insulin (or lower dose) on fasting days?

    1. I’m sure insulin-dependent diabetics could adjust their insulin regimens to accommodate an intermittent fast, but it would require great diligence.

  339. I am 58 years old and think I have finally found a plan that I can live with. I have been successful with other diets but have always fallen off the wagon and gained it back. I work out with weights, and do moderate cardio, but now need to lose about 60 lbs. I think I can do it with IF. I started several days ago and it has been a breeze. I am doing 19 hours fasting and eating in a 5 hour window. I do not think I am overeating in the window so far and I am going to try to do as much low carb as possible. I do like carbs though, but I so far notice I fill up rather quickly when I end the fast.
    I will keep you posted, but so far I think it is going well. I am so far doing the IF daily, but may relax some on the weekends (to do family stuff if you know what I mean). Any tips or help is greatly appreciated. Thanks.

  340. Another note:
    I would also like to hear other comments or findings related to other benefits of IF. I have a son that suffers from cholinergic urticaria, and am wondering about IF helping him with this. Dr. Eades?

  341. I am an insulin dependent diabetic and do the IF from time to time. It is just a matter of dosing your insulin to match your liver output. If you are using a slow acting insulin like Humulin N or other 12 to 24 hour product, you can just use this during the fasting periods. Save the quick acting for your meals. It is not difficult to manage.

  342. Would this work for a compulsive overeater? Assuming I can control myself enough to fast for the required 24 hours, would all of the work be undone if I were to consume something like 4,000 calories in the 24 hours i was able to eat?

    1. It would work much better than consuming the 4000 kcal every day. The beauty of the program is that you can chow down to your heart’s content on the eating days as long you don’t eat on the fast day.

      1. dr. eades,
        does eating a huge amount of calories (overeating) in one sitting spike insulin levels? also, isn’t is hard on the body and digestive system? i’ve been reading a lot about IF lately and there are 2 methods that many people seem to be using – Eat Stop Eat by brad pilon and the warrior diet by ori hofmekler. ori eats like his whole day’s worth of calories pretty much in one sitting. wondering if that’s bad for the body and insulin levels.

  343. That’s what I really love about IF. I eat without worrying about over eating. I keep my menus low carb…very low carb and eat to my heart’s content. I have never gotten to that “I’m gonna burst” feeling eaither. Once I begin to feel satiated, I stop eating because I don’t want any more food. There are days when I feel like I am just “starving” and I am full after a few bites. So some days I eat more than on others. ALso, when I began doing IF I began by eating breakfast progressively later each day. Eventually I was able to go until 3:00 PM before breaking my fast.

  344. ——————————————————————————–
    when it says working out in a Fasted state, does that mean to work out fasting?Do you eat a Pre w/o meal?bcaa/protein shake?
    I understand 16-8hr rule ,about 3x a week I do 2x a days workouts,when would I eat after I workout?
    morning & late afternoon?
    Does IF burn more calories?
    Does one have to Fast more than 16hr?

  345. I just started your program suggested in the blog for IF this past thursday since because of living overseas right now and not having my own way to control my whole meal plan at the moment. It has been going very well and I am already down 2 kilos and have been able exercise just fine while fasting. I am excited because I have a lot of weight to lose and I can’t seem to stick to any other diet at the moment either. I have a primary health concern that I wanted to ask about. I really want to have more children but my FSH has gone up to 15 this year. I want to know if IF and or low carb can help me to improve FSH levels and or fertility-many have suggested lowfat vegan diets for this but I can’t stick to it and my depression and irritability go way up on that diet. Any info would be greatly appreciated as I have already failed IVF and am out of ways to help myself as acupuncture, wheatgrass or Chinese herbs are not available here.

    1. Don’t know if low-carbing or IF will help your particular situation, but I can’t tell you how many patients I’ve lost to pregnancy. These are women who had become infertile because of their obesity and weren’t practicing birth control as a consequence. They started the low-carb diet and got pregnant within a couple of months. I never checked FSH levels on these ladies, so I don’t know what the levels did on the diet.

  346. I forgot to express my extreme gratitude to you because when I tried to do Fast 5 and JUDD several times in the past, neither worked for me because I couldn’t get past overeating but I find with having a day of eating for longer hours much easier and pleasant for me. I think the particular form of IF that works best is dependant on the person, I am just happy I finally found one I could stick too.

  347. I have been looking into fasting for some time now for both health and religious benefits. I have done a fair number of 1 day, 3 day and one 9 day fast. I hope to do a 40 day fast someday.
    The one thing about the 3 day fasts is how much better your digestion feels after getting ‘cleared out’. I am going to start IF but to begin with I will do twice a week (Tuesday/Friday) going from 6PM-6PM. I’ll be back to share my findings and any changes I make in my program.

  348. Sounds interesting enough to give it a try…. not eating 🙁 … but ok lets try and see what happens thanks for the info!

  349. I began doing IF three weeks ago by fasting for two 40 hour fasts on Tuesdays and Fridays. I would stop eating around 6pm the prior evening and not eat again until Wednesday a.m. and Saturday a.m. I did this 3 times and was beginning to make a little progress, noticing that my clothes were a bit looser and my skin looked better when I stumbled across this website and read about the 6pm to 6pm (24 hr. fast) so I decided (against my better judgment) to try it by doing 2 fast per week at 6pm to 6pm even though in my younger days, I could go all day without eating and then eat a large meal at night and GAIN weight, but as long as I did all my eating by 1:00 pm, I lost. That was back when I was young and still had my girlish figure and metabolism. I’m 46 now and struggling to get my figure back. I’m about 30-40 lbs overweight at 5’8″. Anyway, I found that doing the 6pm to 6pm 24 hr fast caused me to obsess and plan all day long about the meal I would get to eat at 6pm and when the time finally arrived, I was STARVING like a ravenous dog!! I know it’s probably mostly psychological, but nonetheless, it is Friday and I’m doing my 40 hour fast again after having done two 6pm to 6pm fasts and have gained back whatever I lost and then some judging by the way my clothes are fitting today. It is so discouraging because I love to eat but I hate being overweight. Life is truly not fair in this aspect since when I was younger, up to my 30’s, I could pretty much eat whatever I wanted, and if I put on a few pounds, I’d go to Walmart and get some Metabolife 356 with ephedra and drop the weight in no time. Since the corrupt Fatal Drugs Allowed (FDA) took that off the market while leaving hundreds of dangerous, side effect, death causing pharmaceuticals), I haven’t been able to keep the weight off. Anyway, just wanted to get this off my chest. I’m feeling down and discouraged today and am starting over on my Tuesday and Friday 40 hour fasts, hoping to see progress again. It’s easier for me just to put food out of my mind and go all day long until the next day than to try an “eating window” during the day because I will eat like a 7 foot tall lumberjack during the “window”. At least my skin looks better but I don’t know it’s the fasting or the Resveretrol supplements I’ve been taking for the past month starting to kick in. I’ll come back in a couple of weeks and let you know if the 40 hour fasts twice per week are working.

  350. I have filled my head instead of my stomach today on lunch break. What a great article and ensuing comments. I guess I’m the last guy on the planet to get up to speed on IF, but here goes!

  351. I’m the handicap guy confined to to a wheelchair I want to follow your program I’M on limit budget SSD.I was wondering if you’ll take me on pro-bono or give me a site I were I can get more information on what to do.

  352. This sounds great. I see lots of meat eating going on in this low-carb IFing. Would it be a reasonable plan for someone who does not eat meat but wants to still go low carb? Seems like the meat protein is what is allowing you to feel full for long periods of time. Could you-or some non-eat meaters doing IF- recommend non-meat proteins that work similarly. Also, I see lots of people taking supplements while IFing. As a 37 year old female carrying 30-40 extra pounds who has never taken supplements (though Dr. said I could definitely use an Iron supplement) can you recommend supplements I may want to be taking while following a non-meat, low-carb IF lifestyle.

  353. I’ve learned for a term ‘intermittent fast’ an hour ago. However, this is exactly how I lost 100 pounds about two years ago.
    My story is typical. I’ve started dieting 15 years ago, at first to lose 5 pounds and gradually, through those years, 5 pounds turned to 100. In summer 2008 I discovered fasting. For me fasting was first ‘diet’ ever, that worked more than 3 days in a row. I fasted 20 days without any problems. However, when one has 100 pounds to loose, fasting is not an option. Once you finish 20-30 days fast you find yourself on the uncharted territory again and through re-feeding time, regardless how carefully you eat, pounds mercilessly come back as fast as they were off. At least, that was my experience.
    So, I ‘invented’ my system. I was eating once every third night, usually, a dinner around 7 pm. On the several occasions, I broke that 3-day ‘chain’, primarily due to social events but the point is that I lost all my weight in 4 1/2 months.
    Now I have to admit, I’m and always have been vegetarian, or better–quasi vegetarian, i.e. I do not eat white or red meat but I eat seafood. So my dinners were based on ‘eat what you want’ concept except for meat and sugar. Usually, that meant some fish, salads, veggie sprouts, beans, occasionally eggs, a lot of fruits. In the beginning those meals looked like binging feasts but as my stomach became smaller my meals became smaller too. It happened very effortlessly and naturally.
    Now, two years later I’m still 125, 5’7″ tall, 45 years old and very happy the way I look. I eat everything except meat, sugar and high carbs, but only once a day, in the late afternoon or evening.
    I really thought that I’m alone. Two years ago, fasting experts on the several internet sites and my naturopath-physician, scolded my ‘diet plan’ and warned me about all that protein that I will lose, over and over again. Short, repetitive fasts, they said are extremely dangerous, I may lose all my muscle and I will not get any fasting benefits. I can’t say that I was not concerned but I’m glad I didn’t listen.
    During those 4 months I never measured my ketons but occasional hunger attacks were so short and mild that I strongly believe my ‘diet’ was heavily keton-supported. Obviously, once they are produced, they don’t just disappear overnight.
    I don’t know whether I lost any muscle as I was told, but after an hour in gym everything hurts … So I guess, some muscle is still there. And I can swim and run faster than when I was 20.
    I’m glad that I am (finally) able to share my story and that 3-day fasting program is not as ridiculous as I was once told it is. And I hope that someone else, may find out that as well.
    Congrats on excellent blog!

  354. I did IF for more than 2 years and I stopped for reasons I’ll explain below.
    I only ate every other day. The first few days weren’t easy but I soon got very comfortable doing it.
    The first few months that worked really well and I got to a very low bodyfat level without changing my diet. After a while my body learned to compensate and I got to my normal weight again. I ate _a lot_ of carbs on the days that I did eat. I didn’t know about low carb diets at the time, basically I considered IF an easy way to stay healthy while still being able to eat yummy cookies and whatever else I wanted.
    After a few months it became hard to keep doing this from a social standpoint, since the days I ate flipped every week and having social dinner on the right day was difficult.
    The days that I fasted I never felt the energy boost that is reported for fasting, and I often felt very cold. I assume my body compensated for the lack of available fuel.
    After two years of this I started to develop what I now recognize as insulin resistance – probably due to my very high carb intake on the days I did eat.
    Eventually I stopped doing IF. It didn’t improve the way I felt of course, since I didn’t change my diet. Luckily I now feel great on a paleo 2.0 diet – so far 😉
    In conclusion I can say that fasting every other day is quite easy mentally and physiologically, but social factors make it hard, and if you eat low carb I don’t really see the point of doing IF very much. I get the same low heart rate and relaxed feeling from low carb that I got from IF – minus feeling cold.

  355. I’m currenty 120kg and I’ll be starting this tomorrow! I remember following it in high school, only eating between 3-6pm and I was a lot thinner back then! I’m also beginning a running program, C25K, so it will be interesting how the weight will come off!! Will keep you posted!

  356. Dr. Eades, have been on a VLCD since Nov last year, lost 65 lbs, but still having headaches I know to be from blood sugar. I have Insulin Resistance. I saw your post about Salt, and Potassium, and Copper, but these haven’t seemed to help. Any thoughts/suggestions? Can’t think well at work with them and I know that I am all out of whack, and trying to reverse this thing. Thanks!

  357. It is really nice to read some positive words about intermittent fasting. It is truly the only method I ever tried that resulted in significant weight loss and lasting weight control. I practiced it for several years quite some time ago with spectacular results. As I began to build muscle from my daily workouts I slowly regained some weight but it was muscle and my clothes still fit. Then I started listening to old “parent tapes” in my head about “starving myself” when in fact intermittent fasting is voluntary and starvation is not. I forgot that “breakfast is the most important meal of the day” only for General Mills (sorry, any GM folks in the room). All I did was gain weight. Well, I’m getting on in years now and have had a few health problems. Now that I’m minus my gallbladder I decided to try intermittent fasting again. I fast three 24-periods per week, 6PM Sunday to 6PM Monday; 6PM Tuesday to 6PM Wedesday; and, 6PM Thursday to 6PM Friday. I don’t eat on any particular schedule at all over the week-ends, as eating by the clock is what got me in this fix in the first place. I have lost 10 pounds since 11 April. I expect the weight loss to slow down eventually but I’m certainly not going to fret about it. I always hated counting calories and now I don’t do that anymore. Like many others who have posted comments, I find that on the fasting days I am curiously energetic and of a buoyant mood. For me, intermittent fasting just feels better. Good luck, everybody. How about let’s stick it to the “diet industry.”

  358. Since December 28th I have fasted twice a week (Tuesday/Friday – and changing it to Monday/Thursday a month ago for 24 hours. 6PM/6PM is my goal but I just run a timer from my last meal). I have missed three days in all that time. I have to say I love doing it. It has totally changed my view on food and my weight is steady. (I do not keep losing weight) For me it has never been about losing weight but clearing out the digestive tract and having discipline. I will say, right off, there is never a good day to fast because there are always good meals to be eaten but with the Eat Stop Eat you never go a full day without eating. I highly recommend it.

  359. anyone have any opinions on IFing if you’re not in the best health and have hormonal imbalances/adrenal fatigue/weak immune system? i’ve heard that people with health issues like that should not IF.

  360. I tried this for a couple days, for a trial run last week… I experienced lack of a real hunger, interestingly. I typically work out from 10:30-midnight, after which I’ll go have a protein shake before bed. I’ll fast from then until about 5:00 the next day, and I’ll eat eggs, ground beef or ground italian sausage, and salad. I might have a protein shake around 7:30, then my postworkout shake. Anything here that you would tweak, Dr. Eades? I’m 350 looking to drop about 100 lbs.

    1. Wow that’s a lot of workouts… did you know that you can get muscle growth and endurance training from just two half-hour weight sessions plus 10 minutes of sprints per week? Too much workouts can actually delay weight loss…
      Check out the primal fitness guide on marksdailyapple. You’ll need to subscribe (free) to get it. I’ve been doing it for a couple of weeks and I really notice the difference…

    2. Look in amazon at the 4HB. A book by tim ferriss. You could easily drop does 100 pounds in a year or less

    3. Victor, you need to add fruits, vegetables, whole grains and legumes to that diet. You can not lose weight by eating ground Italian sausage. If you weigh 350 pounds, just walking would be a good weight workout for you. The best workout time is morning hours. You shouldn’t be working out 10:30 to midnight. That disturbs sleep and adds to weight gain.

  361. Here are some interesting results. I fasted two days/week, 32 hour fasts, for 3 weeks. (I am now fasting one day a week).
    Blood glucose went from 102 (last years reading) to 95.
    Cholesterol went from 238 (last yr) to 194.
    LDL went from 168 to 135
    Otherwise my diet is unchanged.
    I plan to continue a 32 hour fast one day a week and ask my doc for a new blood test in a couple of months.
    Wasn’t trying to lose weight but a few pounds was nice.

  362. I was intrigued, so I began IF on April 30, and have been successfully fasting every other 24 hour period since. I feel good, even better on the fasting days, but I haven’t had the blood work done to show changes. I think a natural result of intermittent fasting is caloric reduction (who wants to suffer through a day of no food and then blow it with a lot of garbage?), and I have as a result lost about 6 pounds. I plan to continue into the fall, and see how it’s going in another 3 months…

  363. Very interesting read, I’ve recently tested positive for HLA-B27 which is a blood marker for Ankylosing Spondylitis, I’ve suffered lower/upper back pain not to mention hip pain for the past 18yrs,(i’m 40 now), now since i’m a muslim part of my faith is fast for 30days once a year, from dawn till dusk(you eat NOTHING at all, not even a drink of water,not even chewing gum). Fasting happens various times of the year and this year (2011) it will happen around Aug 1st till 31st. So as you can see the fasting month has been occuring when the days are long. What I realised my pains in my back and not to mention my fatigue had gone. I thought it was something to do with what i was eating and most evidence points to starch as being bad for AS suffers. So i can only conclude my conditon improved cause i was starving my body of starch.
    When i’ve fasted when the days were shorter, eg in winter months, i didnt notice any pain relief ,non whatsoever, i believe because i was not starving my body long enough. My point being i guess fasting does have some real health benefits when doing it for a long period of time say 16-17hrs a day.

  364. I’ve been fasting 3 days a week for almost a year, and two days a week a year before that. I decided on three days as that puts me at about 40% reduction of cals. I combine Monday and Tuesday into one fast, eat lightly on Wednesday, and fast again thursday. I know I’ve lost some wt. but not lots~~still kinda chubby—BUT I DO FEEL GREAT! have not had blood tests or any such thing, so I have no idea how much my overall health has been effected. I do know, I look forward to my Monday/Tuesday fast, I feel there is a detox component to 60 hour weekly fast— I mega dose on vitamin C during the detox (about 15 grams powdered) for a powerful “evacuation” on all days. I can’t begin to tell you how good I feel on Tues and Wednesday morning (I honestly don’t want to ruin the feeling with food— but ya gotta eat…)My thursday fast is just a prelude to the inevitable Friday night out, and having people over on Saturday and all the drinking that goes with that. Sunday, I usually wish I had fasted Friday and Saturday, but I know Monday is coming— my great day of re-booting!

  365. I am starting tomorrow. I will drink Vega protein shakes tow meals per day and then Dinner at 6. Every few days I will fast during the day and take Map Amino acids and Taurine.
    I hope I will be ok because I have adrenal fatigue and am pre-diabetic
    I will let you know my numbers and how i feel..