Contradictions and Cognitive Dissonance: The (Kevin) Hall Effect

Have you seen the guy on the smart phone video popping up all over the internet saying he has disproven the carbohydrate-insulin hypothesis of obesity? His name is Kevin Hall and he must be experiencing some real cognitive dissonance. Or I certainly am, given the sharp contrast between what his study results actually show and what he’s saying they show on the video. As we all know, cognitive dissonance occurs when we try to hold two opposing views in our mind at the same time, when we experience a disconnect between what we believe and what reality serves us up. And Hall certainly appears to have a disconnect.

Kevin Hall

Or maybe it’s me. Maybe my confirmation bias is blinding me to the truth. Because when I look at Hall’s results, what we can see of them, they imply something entirely different than what he’s saying. Let’s try to figure this out. Let’s delve into the recent study Hall just presented at the World Obesity Federation meeting in Vancouver and compare it to the video now making the rounds, and his explanation of what it all means. Maybe we can figure out who’s off base here: Hall or me.

While the interview with Hall suggests this is his study, it was actually a collaboration of researchers, including very senior folks at Columbia University and Pennington in Baton Rouge and TRI in Orlando. The study Hall is talking about also seems to have been a pilot study, and the word “pilot” implies that the researchers knew there would be inherent limitations when they started it. So right there I’m wondering why Hall has such confidence about what he thinks he’s proven.

The results are in, but as yet unpublished. Hall just presented the data in poster format at a big international obesity conference. Nothing out of the ordinary until he was approached to do a video interview. Hall then did something extremely bizarre and this is the cognitive dissonance: He spent over ten minutes in this video interview completely misrepresenting his own work, so I’m wondering also if maybe he’s going rogue here. Maybe he’s taking the opportunity to say something publicly that his older and presumably wiser colleagues wouldn’t agree with. I’d like to think so, because what he’s saying makes very little sense. This is why journals don’t like scientists to talk about results before they publish the paper. Without the paper, none of us can tell if the scientist is spinning the data to satisfy some pet agenda. Gullible folks on the internet and in the press can then take it and run, which is what happened here.

A few years ago, I had a conversation with Gary Taubes, one of the founders of NuSI, about who was going to do the research NuSI funded. I assumed they were going to fund Jeff Volek or one of the other prominent low-carb researchers currently working. No, Gary told me, they were going to fund researchers who were not pro low-carb, but who were, if anything, low-carb naysayers. Influential folks who had spent their careers insisting that a calorie is a calorie. That way the results of the studies wouldn’t seem tainted because pretty much everyone knows that researchers can see what they want to see. They are afflicted with the confirmation bias themselves. So if nonbelievers did the study, Gary said, no one would question the results. Kind of like an organization of atheists hiring a bunch of cardinals from the Vatican to do a study they think will demonstrate that God doesn’t exist. Sounds like a good idea, but you can see how it could go wrong.

Feel free to accuse me of indulging in the hindsight bias right now, but at the time Gary told me this, I was a little worried. Just as researchers can see what they want to see, they can also not see what they don’t want to see. So I was concerned that researchers who weren’t at least neutral on the low-carb issue might not come up with entirely accurate results. Think about it. If you spent 15 years of your academic career insisting that a calorie is a calorie, would you like to publish a study with strong data more or less negating what you’ve been saying all your working life? Especially if you had publicly ridiculed that philosophy in years gone by? If you were Kevin Hall and you spent the last year insisting that low-fat diets were the best way to lose weight and that you’d already refuted the carbohydrate-insulin hypothesis, wouldn’t you be tempted to spin your data to suggest that you’re still right?

Like Donald Trump on TV, Hall and his video appear every time I fire up my browser. The widespread response to the video seems to be an ink blot test separating those who believe there is a metabolic advantage with a low-carb or ketogenic diet and those who don’t. It has stoked non-believers into competing over who can throw up the most gloating post the most quickly. The internet is crackling with writings from all the calories-in vs calories-outers (CICO), who believe only calories matter. And, thanks to Hall’s video, they are absolutely topsy turvy over the moon with glee. Bloggers who have spent the last years insisting that they can read and understand the details in research papers better than the rest of us are now taking victory laps based on a ten minute interview and no paper at all. Talk about cognitive dissonance.

I think it would be nice to have the actual data and the final peer-reviewed paper itself before we make claims, which is why I wonder what Hall’s agenda is here. But I have my confirmation bias to deal with also. Based on a lot of experience with patients and deep digging in the medical literature, I think and have said for years that the human body will waste calories when it’s mobilizing fat. I think it mobilizes fat when we don’t eat a lot of carbohydrates and that results in the metabolic advantage we’ve been talking about.

What is the Metabolic Advantage?

Let me digress a bit here. I use the term “metabolic advantage” because it’s one most people are familiar with and how we’ve been discussing it for a long time. But realize that the metabolic advantage is really an effect, not a cause. If your insulin is high, it’s going to trap fat in your fat cells and prevent other cells in your body from oxidizing it. If you drop your insulin levels, you’re going to release this fat from the fat cells and your lean tissue is going to want to take it up and burn it. When that happens, your energy expenditure is going to increase. Mobilizing fat and burning it is the cause. The extra calories burned, the increase in expenditure – what we all think of as the metabolic advantage – is the consequence.

Back in 2007 I suggested that the metabolic advantage amounted to maybe 300 calories a day, although I’m sure it’s going to be different, maybe dramatically different, from person to person. In 2012, David Ludwig’s group at Harvard did a controlled study showing an average metabolic advantage of about 325 calories from a very low carb diet, so I wasn’t much off the mark. At least based on the Ludwig study.

But, according to Hall’s videotaped interview, he seems to think that there’s some science out there suggesting it’s far bigger.

And previous folks have suggested that that should be 400-600 calories a day of extra energy expenditure.

No one I know says the metabolic advantage is 400-600 calories a day, but that’s the least of the issues I have with Hall and this video.

Now with funding from NuSI and the NIH, Hall steps forward saying it doesn’t matter what we all think the metabolic advantage might be, because his carefully-controlled study shows it doesn’t exist, or at least that it’s smaller than he thinks it should be, and therefore it doesn’t exist, or kind of doesn’t exist. It’s a little confusing because, again, what Hall says in the video is contradicted by what Hall and his colleagues write in their abstract and so presumably their paper.

Unless you’ve already seen it, take a few minutes to watch the video below. As you listen to Hall describe his research and explain his data, see if you can figure out what the take home message is. It shouldn’t be difficult. After you’ve watched, skip on down, and we’ll pick it back up.

Okay. So, what did you think? Did he find a metabolic advantage or not?

Just so we’re all on the same page here, another term for a metabolic advantage is an energy expenditure increase on a fixed number of calories. In other words, burning more energy while taking in the same number of calories. Many people, myself included, believe that changing from a high-carb diet to a low-carb diet of the same number of calories allows people to increase the amount of fat they burn, and that manifests itself as this metabolic advantage. Their energy expenditure increases, even while they’re losing weight.

Also, bear in mind that not too many years ago there was a movement in the CICO community to try to get everyone to simply decrease their caloric intake by a mere 100 calories per day. To do so, said the experts, would ultimately get rid of the obesity epidemic.

So if a study suggested that people increased their energy expenditure by 100 calories per day simply by switching to a different diet wouldn’t that be a good thing? Only 100 calories per day. Remember that number because we’ll be coming back to it.

You’ve heard what Hall says; now let’s take a look at what he and his colleagues write for professional consumption in the abstract of the same study he discussed in the video. This is the official abstract published in the program of the World Obesity Federation, International Congress for Obesity (ICO) meeting in May 2016 in Vancouver. You have to click the link, scroll down to the bottom section and about 3/4 of the way down on the left, you’ll see K.D. Hall. Click the title to the right of his name, and you’ll be presented with the abstract.

If you don’t want to go through all that, I’ve pasted it below. The reason I want you to be able to find it yourself is so you won’t think that maybe I’ve altered it to make my point that it bears so little resemblance to what Hall’s saying in the video. See for yourself.

KD Hall abstract

Pretty astonishing, eh?

First, take a look at the title. Authors summarize their papers in the title. This title is pretty clear: “Energy Expenditure Increases Following An Isocaloric Ketogenic Diet in Overweight And Obese Men.”

Remember, an energy expenditure increase on an isocaloric diet = a metabolic advantage.

So, another way of writing the title would be the following: A Metabolic Advantage Follows an Isocaloric Ketogenic Diet in Overweight And Obese Men.

Right off the bat with the title alone, we’ve got cognitive dissonance. How can Hall say the data from this experiment produced no metabolic advantage when the title of his paper says the opposite? Good question.

Let’s take a look at some of the specific data he presents in his poster. Along the way, I’ll air some gripes about how the data were (or weren’t) presented.

The Poster and the Poseur

Here is how the experiment was done. The researchers confined 17 obese subjects to a metabolic ward for 8 weeks. During the first four weeks, the subjects consumed a baseline high carb diet, then switched to a low-carb/ketogenic diet for the last four weeks.

What was the macronutrient composition of the two diets? We can’t tell from what Kevin says.

We don’t know what the actual macronutrient composition of the lead in diet was because it isn’t revealed in the poster or in the abstract, so all we can do is infer from what Hall says in the interview, which is:

…so here is the study design, basically. Two months onsite metabolic ward. Basically the first period is a baseline diet, high carbohydrate diet, 25% of total calories coming from sugar and every week they spent two days inside a metabolic chamber. And basically what we do is over the first period of time we adjust the number of calories to match what they were burning inside the chamber so that we put them in energy balance inside the chamber and then we clamp the calories for the rest of the period of time and switch them to an 80% fat 5% carbohydrate diet keeping protein clamped all the way along.

I navigated through the NuSI website until I found the link to the info for the lead in diet, which was 50 percent carbs, 15 percent protein and 35 percent fat. Then over the last four weeks the subjects ate a diet made of 80 percent fat, 15 percent protein, and 5 percent carbs.

Each week, each subject spent two days inside a metabolic chamber. A metabolic chamber is a very expensive small room in which precise measurements can be made of energy expenditure. The idea in Hall’s study was that they were going to measure people’s energy expenditure in the metabolic chamber on this run-in diet and that would tell them how many calories they were expending. Then they could feed them that many calories and that would be a weight maintenance diet.

But immediately Hall tells us there was something wrong with using the metabolic chamber. As Hall says, much to their surprise, they found out that the energy expenditure of subjects in the chamber is unnaturally low. So when the researchers fed the subjects the number of calories they thought they needed as revealed by the metabolic chamber they were dramatically underfeeding them. There was quite a discrepancy. Says Hall:

One of the interesting things was that despite the fact that we were trying to put them in energy balance in the chamber and we were actually able to do that. Um, outside the chamber they actually burned more calories. Not too surprising in retrospect but we actually were surprised by the magnitude of how many more calories they were burning outside the chambers. Upwards of 500 calories a day more outside of the chamber than inside the chamber. So what that meant was that we were feeding them more or less in balance in the chamber but we were underfeeding them outside the chamber.

When Hall says, “not too surprising in retrospect,” he might as well be saying “oops!” And what he also means when he says that is his own colleague and last listed author on this study, Eric Ravussin, published this finding 25 years ago.  This makes me wonder why they didn’t plan for it in advance. Oops again.

So, each subject was spending two days per week in the chamber, leaving five days per week spent outside the chamber. According to Hall, during these five days outside the chamber, the subjects were being fed about 500 fewer calories than required for their weight maintenance and energy balance. Aside from the fact that this makes it a very sloppy study — the oops! factor — and makes me wonder again why Hall is so smug and confident, there’s another interesting issue it brings up that I’ll address in a bit.

The results for the various parameters measured during the 8 week study are shown in graphs displayed on the poster. It aggravates me that only the last two weeks of the first four week baseline study are displayed. In my view, it would have been just as easy to show the entire thing. As it is, it implies that the first two weeks mirrored the last two weeks of the baseline, therefore didn’t need showing. But we don’t know that from what we can see.

Below is the poster for the study (click to enlarge).

Hall poster

Let’s look at the results in some of the sections.

Fat loss over time…

Weight loss over time

I don’t know about you, but it’s pretty clear to me that weight loss accelerated once subjects were switched over to the ketogenic diet. The fat mass, as portrayed by the broken line, seems to level out a bit as the subjects start on the ketogenic diet, but then appears to resume its same rate of decline for the last two weeks. (Remember we don’t know what it was the first two weeks of the run-in period, so we have to take Hall’s word for it and clearly that’s a questionable thing to do.)


Okay, so what happened… The blue period of time, this is the last 15 days of the baseline run-in high carbohydrate diet so they’re losing weight slightly. It’s a roughly 300 calorie a day negative energy balance over all. They’re losing fat over this period of time. We switch them to the low carbohydrate diet, they lose a good chunk of weight about 1.6 kilos right away. Interestingly, and I think most importantly for the carbohydrate insulin hypothesis is that the fat mass [sic] slowed.

I’m pretty sure that Hall meant to say the fat loss slowed. It did, but only briefly. Then it picked back up. And it slowed during the period when one diet transitioned to the other. I’m a little confused about the calories now. At first Hall said there was a 500 calorie a day negative balance, and now he says it’s a 300 calorie daily deficit. Did he misspeak the first time or this time or was the 500 calorie deficit during the baseline diet and the 300 calorie deficit during the last four weeks? We don’t know.

One of the things that I find very curious here is that Hall never mentions in the video whether they measured ketone losses in breath and urine and fat loss in feces. And I can’t find any discussion of it on the poster. I sure hope the paper will have these data. If you’re going to claim to to have done any kind of definitive experiment on how energy expenditure and fat loss change between two different diets, then it seems you have to make every effort to track energy and fat.

These can be expended — and that will show up as changes in energy in the calorimeter — or they can be excreted and that won’t show up in the calorimeter, but is still energy loss just the same. Hall is talking about measuring the expenditure, but not the excretion. Calories are lost as ketones in breath and urine; fat is lost in feces. Did they measure those? And if they didn’t measure it, how can Hall make any claims about what’s happening here, even these contradictory ones? I hate to sound like I’m nitpicking, but isn’t that one of the things that science is all about — getting the details right. In the ketogenic diet, they’re feeding these people a couple thousand calories of fat every day and they should be mobilizing the fat they’ve stored. We can expect some of this to show up in feces. It would be nice to know. And if it doesn’t, that would certainly help make Hall’s point. I wonder why he doesn’t show it.

And the changes in Insulin…

insulin levels over time

C-peptide levels are a measure of insulin production. The beta cells in the pancreas produce proinsulin, which splits into a molecule of C-peptide and a molecule of insulin. The C-peptide remains in the circulation and is a proxy for insulin production because one molecule of C-peptide is made for each molecule of insulin.

The chart above demonstrates that switching from a high carb diet to a ketogenic diet truly does drop insulin levels quickly.

If the carbohydrate-insulin hypothesis is correct, Hall claims, this drop in insulin should result in a big increase in energy expenditure. Why? Because, well, let him tell it:

…basically we were really interested in the idea of trying to test this carbohydrate insulin hypothesis for obesity which posits that basically obesity is caused primarily because of high insulin levels which are driving fat into fat cells starving the rest of the body and thereby basically causing increased hunger and decreased energy expenditure.

So one of the logical consequences of that model of obesity, if it’s correct, is that if I take people who are overweight and have Class 1 obesity, if I then swap out, keep the calories the same, but swap out carbohydrates for fat. In particular if you crank down the carbohydrates really low to 5% of total calories and increase fat to 80% of total calories, that you would reverse some of these things.

And if I clamp, basically, the number of calories then I’m not going to be able to test the effects of hunger but I will be able to test the effects on energy expenditure.

So what happened to energy expenditure?

Okay, so we’re looking for an increase in energy expenditure if the carbohydrate-insulin hypothesis is valid because we’re not really testing that hypothesis directly, despite what Hall says (and I’ll get to that in a moment, too). So let’s look at the next two graphs.

increased energy expenditure on lketogenic diet

The top one shows the overall energy expenditure as measured in the metabolic chamber and the next one down shows energy expenditure measured while the subjects were sleeping. The sleeping energy expenditure is a measurement of fat burning during fasting. If insulin levels are high, holding fat in the fat cells, then you would expect sleeping energy expenditure to be low, as it was in the blue part of the chart, the last two weeks of the high-carb diet. On the ketogenic diet, insulin falls like a rock, allowing fat to flow easily from the fat cells to meet the body’s needs. As this fat is burned during sleeping, you would expect to see an increase in energy expenditure during the ketogenic diet, which is exactly what you see. Again, that’s a nice metabolic advantage.

Now what are you going to believe? What Kevin Hall tells you the study showed, or your own lyin’ eyes?

What does it all mean?

Nullifying the Facts?

An important missing point to keep in mind in Hall’s discussion is the idea of the null hypothesis.

Every hypothesis test requires the analyst to state a null hypothesis and an alternative hypothesis. The hypotheses are stated in such a way that they are mutually exclusive. That is, if one is true, the other must be false; and vice versa.

If you google “hypothesis testing”, you’ll find dozens of sites like the one linked above and this one — Wikipedia’s — that explain what these experiments are doing, which is they test the null hypothesis. You can also ask any biostatistician, if you happen to have one in your neighborhood. Hall says from the get-go — both in the video and in the poster — that he and his colleagues are testing the carbohydrate/insulin hypothesis. But that’s not the null hypothesis. (If obesity researchers had been doing their job right for the past 50 years, it would be.  But that’s a topic for another post.)  The carbohydrate/insulin hypothesis is the alternative. In Hall’s study the null hypothesis is that obesity is an energy balance problem. It predicts that as far as fat storage and energy expenditure are concerned, a calorie is a calorie. It doesn’t matter what the diet composition is — all that matters is calories. Change the diet composition, according to this null hypothesis, and it makes no difference in fat storage or energy expenditure.

The alternative hypothesis is that obesity is a hormonal disorder (too much insulin driving fat storage). If it’s correct, then changes in macronutrient composition designed to reduce insulin levels would result in decreased fat storage and increased energy expenditure even if caloric intake were kept the same.

The main thing Kevin Hall’s study is doing, the primary thing, is testing the null hypothesis, and it’s kind of mystifying to me why he presents it any other way. If he refutes the null hypothesis — which I think would be pretty damn interesting, since that hypothesis is the basis of all our public health and research and medical thinking on obesity — then he can say whether the result goes in the direction he would expect from the alternative hypothesis or not. In this case, that would mean an increase in energy expenditure when his subjects switched to the low-carb diet.

If the null hypothesis were correct, we should find no statistically significant change in energy expenditure and/or fat accumulation. If we find either, then the null hypothesis is rejected and a calorie isn’t simply a calorie.

Since there is no specific data on fat accumulation in the poster, we can’t tell the difference there. All we’ve got to go by are the graphs shown, which are difficult to interpret, and what Hall tells us. The energy expenditure is a different story. Those figures are published in the abstract.

The ketogenic diet coincided with a rapid and persistent decrease in respiratory quotient (mean±SE; ­0.111±0.003, p<0.0001) along with increased total energy expenditure (+57±13 kcal/d, p=0.0004) and sleeping energy expenditure (+89±14 kcal/d, p<0.0001) measured by metabolic chambers. Energy expenditure measured by doubly labeled water increased by 151±63 kcal/d (p=0.03).

The increased energy expenditure numbers from the metabolic chamber are highly statistically significant, meaning there is very little probability these findings occurred by chance. The energy expenditure measured by doubly labeled water is more than twice as high and still statistically significant. And the interesting thing about that, remember, is that Hall told us ‘something weird happens in the chambers’ because the subjects expended 500 calories a day less inside the chamber than out. Remember the oops!? Hall tries to make light of that, but that’s the equivalent of running half a dozen miles a day in the ward, while not moving at all in the chamber. Now I don’t know about you, but as a doctor I’ve been in plenty of hospital wards and I’ve never seen patients running laps in the corridors. So something weird is happening in the chamber. And it suggests that the measure of energy expenditure outside the chamber, in the ward itself, is the more meaningful one.

It isn’t really shown in the poster and Hall only briefly alludes to it in his interview, but there it is prominently stated in the abstract. The energy expenditure measured by doubly labeled water includes the five days each week the subjects are on the wards. It’s not just the two unnatural days in the metabolic chamber. And it increased by 150 kcal/day. That’s a hell of a lot of energy considering all the things we don’t know. Enough to roll back the obesity epidemic and bring people’s weights to 19th Century levels if it was maintained day in and day out.

The fact that the energy expenditure is increased at such highly significant rates rejects the idea that a calorie is a calorie — the null hypothesis. Hall can argue this till he’s blue in the face and mug condescendingly into the camera all he wants, but his own abstract tells the story.

Both the chamber and the doubly labeled water measurements show a definite increase in energy expenditure and they both reject the null hypothesis while going in the direction we’d expect from the alternative one. Based on the data presented (and the data that may not have been measured), the study appears to be poorly done. (Oops!) But what they report seems clearly to contradict Hall’s spin.

If you want the final word (so far) on this pilot study, just look at the last sentence in the abstract. Remember how I said I would come back to the 100 kcal/day?  That’s the amount, you recall, that the CICOers said would solve the obesity epidemic.  We’ll there it is.

Therefore, an isocaloric ketogenic diet was associated with increased energy expenditure of ~100 kcal/d.

There’s one last point I want to make and it’s about the use of the words “associated with” and “coincided” in the abstract: “The Ketogenic diet coincided with….” It doesn’t say the diet caused what they saw. It only says it coincided. I think that’s because the study wasn’t a randomized trial. Maybe the changes they saw would have happened on any diet after the first four weeks. So statisticians would say they can’t “infer causality” and older and perhaps wiser scientists than Hall would know that, which may be why what the abstract says and what Hall says in his video are so different. Hall is saying what he’d like to believe he’d done. The abstract says what he and his colleagues have actually done. As I said, they seem to be two very different things. I can’t wait to read the actual paper when it gets into print to see what it really says, and whether this study is really as bad as Hall suggests in the interview.

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106 thoughts on “Contradictions and Cognitive Dissonance: The (Kevin) Hall Effect

    • I use to weigh 255. I now weigh 192 with a 34 inch waist. I am 60 year old Masters athlete I have gone from akins, ketogenic, carbnight and, carb back loading. Ketogenic works the best for weight loss. I can do better with my anaerobic training with carb cycling, but have to work hard to stay lean on carb cycling. When I eat normal american diet I gain weight fast. When this happens, I always go back to Taubes’ book, “Good Calories Bad Calories” and read it when I gain weight. Gone u p to 213 If Hall is correct, and if I base my diet on his science, I will get fat. This is not science but it is the truth.

  1. NuSi should instead of seeking out anti/pro/agnostic low/high carb etc folk from nutrition/health research to do the studies, pick scientists from a completely unrelated field – particle physics or something – a field where they simply don’t care. This is why I loved the Credit Suisse report from last year – a bunch of investment bankers just wanted to know where to stick their $, and uncover a truly broken system chock full of WTF psuedoscience.

    The null hypothesis gets scrambled just by switching out “calories” to a single macronutrient – ethanol. If you can make people fat with just vodka, then it’s only the “calories” that matter. This is the science we deserve. *sip*

    And yeah – this all fell on confirmation biased eyes in the ketoscience forum, throwing up more questions than answers:

  2. Fantastic come back…love it.
    Isnt a calorie a unit of heat ? as I read in a book from 1958, and if so fat has 9 units of heat compared to 4 units of heat for protein and carbohydrates.
    So this being the case ..wouldn’t it be obvious that fat helps the body burn twice as much and keeps metabolism up for longer. As the book said…carbohydrates don’t have any nutritional benefit compared to protein.
    Feed someone carbs only they will die.
    Feed someone fats and proteins only they will thrive.
    Proteins and fats are essential for daily human life and all living cells in our bodies.

  3. As Peter has so frequently demonstrated (or perhaps demolished would be more accurate), what is fed matters greatly to the actual biochemistry involved when you study the energy processing going on in the cell. See his Protons series …

    What was the fat in the ketogenic diet?

    • As he’s a Govt employee it seems to an outsider that Hall may be at least under the influence of the sort of activities exposed recently around Nina Teicholz.

      The preservation of the Dietary Guidelines and the reputations of the anointed in this field appear to be high priorities. I hope some US residents dig into this with FOI requests and expose the backstage agenda.

      The US Govt *is* the grain cabal, you need look no further than the Words “National Institute…” to see the problem.

  4. That’s why I’ve been an Eades’ groupie since Protein Power was first published. You do the heavy lifting so that I don’t have to (as if I could figure this stuff out on my own). I’m maintaining my 155-pound weight loss achieved with meat/fat/spices/water and daily weight-resistance workouts. My newest passion is pork belly. Oink oink and I’m strong and toned.

      • I wish there was a ‘like’ button for this thread, but since there is not – thanks for making me smile and making my day Marly and Dr. E!!!

  5. Is it possible that fat loss appeared to slow because that fat being “consumed” by the body was that around the organs like in NAFLD for example? Did they check their subjects for this?

    • Fat should burn the same irrespective of where it comes from, so I don’t think the location would make a big difference.

      • The fat mass is measured using a series of external calculations and body measurements as I understand it. It would not include in any way fat around internal organs (or would it?) His claim that fat loss seemed to slow takes into account external measurement only. If the liver is fatty, this fat would need to clear first before maximum fat usage and conversion to ketones can occur most efficiently. This could explain the delay as manifested by fat mass line in the graph as weight declines……unless I have misunderstood it.

        • To clarify, if internal fat (organs) is used first, then external. Therefore the external measurements will demonstrate a delay as weight falls but fat mass changes appear to slow then increase.

        • The loss of fat is measured inside the metabolic chamber and by the doubly-labeled water method outside the chamber. Both take into account fat around internal organs.

  6. “During the first four weeks, the subjects consumed a baseline high carb diet, then switched to a low-carb/ketogenic diet for the last four weeks.”

    I interpreted what he said differently. To me, it sounded like they did 10 days of creating a baseline. Then, they clamped the calories while maintaining a high-carb diet for another 15 days. Then, they went to a low-carb diet for 28 days. That is why the chart showed 15 days of high carb plus 28 days of low carb. The chart omitted the baseline establishing period.

  7. Hall appears to be basing his appraisal of the study outcome on an expectation; because the study results seem to fall short of the expectation, he is dismissing them. But doesn’t the science lie in the actual results, not the expectation of what the results will be? Suppose I run an experiment to see how many widgets someone can make in a day under specified conditions. My expectation is that someone can make a dozen widgets, but she only makes 3 (or 5, or any number below my expectation). Is my experiment worthless because it didn’t meet my expectation? Or did I learn that, under the conditions I created, someone could make 3 widgets?
    As for Hall’s study, a big question is what did these people actually eat? Some variation of lab chow or real food? (Was all the fat canola oil?) Did they know what was going on? What about controls so we know what happens in these conditions to people eating what would be a more conventional diet? How realistic is it to measure energy expenditure in such a passive way (mostly sitting around)? Does a ketogenic diet change behavior with regard to energy expenditure, i.e., do people become more active when they can mobilize their fat stores? (his results seem to point in that direction.) Is a month long enough? More questions than answers, at least so far.

  8. After following you for so many years with your blogs and book reviews, I have determined that you are a doctor in search of the truth. Your research is thorough. You admit all variables, always questioning results. I didn’t find that to be true with Kevin Hall’s “experiment”, and to pass it off as truth when you know damn well people will run with almost any thing these days even if it seems just a little credulous. I think he was after quick recognition (15 minutes of fame), and will eventually concede certain areas of his hypothesis. How long has he been in bariatrics?

  9. If I ran a eucaloric study of a ketogenic diet and didn’t a) maintain the subjects weight or b) measure blood ketones with a $20 instrument then I would go back to the drawing board. It appears this wasn’t eucaloric, and may or may not have been ketogenic.

    The study wasn’t set up to test the insulin hypothesis as the word “insulin” does not even appear in the NCT trial registration. The primary outcome was energy expenditure, and should be the big thing on his poster. Body mass and fat mass didn’t get a mention either.

  10. wow. it never ceases to amaze me how smart people like Kevin Hall can mislead themselves to such an extent. A gold-mine for psychology students!

  11. If Delta Mass is the delta from a single measurement (presumably at the start of the study), and Day Zero is the day the low carb diet started, then according to the graph, Days 6-9 are the only days when any significant change of weight loss occurred. That would indicate that Days 0-15 are very different from Days 15-30, so I’m not sure why the posterboard presentation would only focus on data from Days 15-30.

  12. Great article, Dr. Mike. When I interviewed you and Dr. Mary years ago for your 30-Day Low Carb Solution and the Comfort Food Cookbook. I was very skeptical of low carb. After decades of dieting (and starving), I did finally return to low carb and keto–and succeeded–and have maintained for four years and counting. This metabolic advantage was the concept I missed somewhere along the way, which explains a lot. Thank you! And keep doing what you’re doing. You’ve helped me get thin and saved me from being starved and cranky–and let’s face it, the world doesn’t need any more starving, cranky redheads.

  13. There are a couple of points that need to made regarding your post.
    Firstly, the increase ?EE & ?SEE appear, by all reasonable assessments based on the graphs provided, to be transient. In other words, whilst both parameters initially increased following conversion to the ketogenic phase of the study and appear statistically significant (assuming the asterisks denote this) they then decrease virtually back to baseline or zero (with no asterisks, so ? there is no longer a difference because they are no longer statistically significant).
    Secondly, I’m not sure how this can be reconciled because the 24-hr C-peptide (insulin) measures decrease and remain relatively stable at around -40% for the duration of the ketogenic phase. By inference then, if what you are saying is valid – that low insulin allows liberation of fat from the adipose tissue and thereby increases energy expenditure – both ?EE & ?SEE should have remained consistently elevated for the entire duration of the ketogenic phase and should have closely correlated to the 24-hr C-peptide. However, this didn’t happen. Both ?EE & ?SEE decrease dramatically over the ketogenic phase in concert with stable insulin level (which can be seen clearly in the graphs provided).
    Thirdly, the gradient of fat mass loss from day -15 to 0 and 15 to 30 looks indistinguishable, which suggests that the rate of fat mass loss is no different between phases. I would have expected to see a 100 kcal/day difference over 1 month (3000 kcal) translate into something more meaningful.

    • They do indeed appear transient, but these are the graphs from the metabolic chamber part of the study that represented (according to Hall’s video remarks) two days out of each five. Hall did not make available the graphs for the doubly-labeled water measurements on the study, so I don’t know how or when those were measured, but were obviously done on days outside the metabolic chamber. The site showing the basic parameters of the study show nothing about it, so we don’t know when it was done. What we do know from the abstract was that it showed a larger average number than the metabolic chamber studies did. Do we know if this slowed at the end? No. I wasn’t shown. Based on how Hall hedged on everything else, I suspect (but, admittedly, don’t know) that it may have remained stable or even increased near the end of the study.

      Based on the charts shown what we do know is that the area under the curve on both graphs indicates a substantial, if transient, increase in energy expenditure. And what we know from the abstract is that this area under the curve was highly statistically significant.

      As to the loss of fat mass, it’s hard to tell from the graphs. And it’s always dangerous to try to extrapolate from graphs such as these. The energy expenditure increases were obvious, but we’ll probably have to wait till the final peer-reviewed paper comes out to see what the fat loss actually was.

      This was a pilot study looking to see if the results were viable enough to justify a more ambitious and expensive RCT. Given the statistical significance, I would say it does.

  14. The proof you need is being done in individual experiments all over the English Speaking world. Here is an article about what we are doing in the real world. I, for one, have quit carbs, quit gaining weight, and am spreading the word. Science will take care of science, we don’t have time out here in the lab of life…

  15. I’m a little bit confused. You say that the graphs show a metabolic advantage of about 150 calories for the low carb diet. If I eyeball the last graph in the your post, it looks like the advantage is indeed about 150 calories at day 5, but by days 20-25 it drops to below 50 calories per day. I would think that the later observations are more indicative of steady state than the first ones. Am I missing something?

    • No, you didn’t miss anything. Usually these things are measured as an average of the area under the entire curve. This was a short pilot study to see if there was justification for spending enormous amounts of money on a larger, longer RCT. Based on the statistical significance of the findings as reported in the abstract, I would say the expense is warranted.

      • Ah, so the interview was “grant-seeking behaviour” and may or may not bear any relationship to the study when actually published.

  16. Drop the temperature inside the chamber by ten degrees, and I’ll bet the 500 calories that magically vanished outside of it would be instantly accounted for. Why do they never look at how much we adapt to expending calories to maintain body temperature?

  17. You make some interesting points but as far as I can tell Hall is simply stating that there was no significant fat loss difference between the keto diet and the carb diet. I’m sure this will be confirmed once the full paper is released.

  18. So what is this RQ mean for keto adaptation? Couldn’t they just measure urine keto disappearance as a measure of keto adaptation? I also question the 1 month time it takes to become keto adapted. I’ve heard of it taking a few months for some people.

    The study participants had lean muscle mass loss during the keto diet. Could it just be that they were not having enough protein in their diet? 15% of calories in the diet was protein so assuming a 2000 calorie intake that would be 75g protein per day. If you are doing keto, you need more protein to support gluconeogenesis, so the diet itself has to be formulated properly.

    • It takes more than simply measuring ketone decrease in urine. RQ is part of the equation. Peter at Hyperlipide has good posts on it here.

  19. Dr. Eades –

    I live a low carb lifestyle. My health has improved tremendously. But it only started working when I cut back on fat. I then started tracking calories.

    Now that I’ve lost weight I’m more liberal with overall carb intake but still mindful of calories, protein, fats, carbs.

    I hope you & Gary understand how important it is to clear up the confusion around calories – even in the most popular LC communities on Facebook the admins have to stipulate that at some point people need to track fat or calories.

    I see so many people now in the LC space saying calories don’t matter – but clearly they do.

    I was introduced into this WOE by you & Mr. Taubes. I’m very grateful for that.

      • Agreed. Warren, I have been strict LCHF since May while my husband has hopped on board to enjoy the pleasures of my higher fat cooking but he hasn’t given up his chips and beer. I am gaining weight and he looks like an Adonis. I research and read, and research and read…and I am doing everything the experts say to do. My sense of failure is overwhelming. I saw Hall’s video, got even more discouraged, then read Dr. Eades response to it and am back in the LC camp. But I also think there may be a mystery to postmenopausal women and metabolism that may not get solved in my lifetime.

    • Robin, I’m in the same category as you. LC Paleo-like does work for me. I feel great, have high energy levels, I can skip meals, go out running in the morning without breakfast, I can go climbing for the whole day hardly eating anything, I haven’t been ill for over 6 years, etc, etc.

      And I can easily gain body fat eating high fat, moderate protein, very low carb. It will happen if I eat a bit too much of the high fat foods. I can gain fat with my ketone meters showing that I’m in ketosis.

      The thing is, it seems any calorie overload will stimulate insulin (cf. Woo’s comments on fat being insulinogenic). I have no doubt that LCHF is much healthier than HCLF, but again some people, like me, can overeat fat and gain body fat.

      • Interesting. I lost weight on low carb, then lost more weight while adding more fat to my diet and performing intermittent fasting (not eating breakfast and/or lunch and/or dinner). I currently perform IF weekly and eat as much fat as possible per day. I think the IF helps reduce insulin resistance, to the extent that protein does not. Unfortunately, I haven’t tried eating three meals a day of high fat, as I find I no longer like to have breakfast; I feel better without it. I also find IF better overall, and this week will eat during a narrow window (a few hours) three days and then eat during a larger window (maybe 8-10 hours. I still try to maximize fat intake, though.

        • When you say you eat as much fat as possible, do you mean pure fat, like butter, lard, olive oil, etc? Or fatty foods, like meats or eggs? It could make the difference.

          I also do IF, basically skipping breakfast and eating only around 1pm. My problem is that whereas I can totally control my food intake in the morning and during the day, I get hungry in the evening, and then I can easily overeat on high-fat foods.

          • Yet another problem that few LC experts write about (with the exception of Peter from Hyperlipid) is that MCT may block (or blocks) free fatty acid oxidation. What then can happen is that at first MCT consumption increases the perceived energy level but then generates hunger.

    • It would be interesting to see long-term studies of people on low carb, high fat diets. I would like to see what happens over time (most all studies have a period where the carb content goes way high, relative to what I eat anyway). And it would be really great to have a LCHF + intermittent fasting (IF) arm. That’s what I do now: LCHF+IF. Then throw in as many other arms as possible: “Mediterranean” (whatever this is), low fat, etc. I predict LCHF+IF would “win”, as it’s helped me tremendously. But I bet the picture wouldn’t be as clear with a lot of people involved. Those people who aren’t insulin resistant, for instance, might have different results.

      • Been eating LCHF for nearly twelve years now.

        I got twelve years older. The End.

        I’ve known not a few diabetics who have been doing it for anything from ten to thirty years. One Type 2 did it for 42 or 43 years (he started back when it was SOP for diabetics) and lived to be 89 without any diabetic progression.

        Who would even consider funding such a study though?

        Non-IR people are I suspect in a minority nowadays, they can handle the carbs but would there be any benefit or disbenefit from a low carb diet? Also would be interesting to see – only downside I can think of is for those with APO-E4 whose LDL may go through the roof.

  20. Obviously, it is upon insufficient grounds, but I instinctively recoil from accepting information from someone who so liberally peppers his language with the word, “basically.” The usage of that word, by itself, even once, is, to me, a potent indicator that the speaker doesn’t know what he is talking about.

  21. “At first Hall said there was a 500 calorie a day negative balance, and now he says it’s a 300 calorie daily deficit. Did he misspeak the first time or this time or was the 500 calorie deficit during the baseline diet and the 300 calorie deficit during the last four weeks? We don’t know.”

    “We don’t know” is, of course, correct, but I will throw out a guess. He says “It’s a roughly 300 calorie a day negative energy balance over all”. I read the “over all” as talking about the average calorie deficit over the full “blue” period. That is for every 7 days, a total deficit of ~2,100 calories. For each 7 day period, subjects spend 2 days in the chamber (w/ no energy deficit) and 5 out of it (w/ 500 calorie deficit per day), which implies a 2,500 calories deficit per week.

    2,100 and 2,500 aren’t exactly the same, but maybe close enough for government work. If the daily “outsode the chamber” deficit was 460 calories, that would work out to an average deficit of 330 calories per day over a full week.

  22. Don’t know hoiw many times I’ve said this, but if a calorie is a calorie, and insulin is not a factor – how does one explain (undiagnosed) type 1 diabetics who can eat mass quantities and still lose weight?.. Seems this alone would invalidate that theory…

    • Once I was going to congratulate Stephan Guyenet for his explanation as to how all Type 1 (insulin deficient) diabetics were immensely fat and all Type 2 (insulin resistant) diabetics were very slim. Then I realised he wouldn’t understand the sarcasm . . .

  23. I think the numbers in the abstract are the average for the month of ketogenic diet. What Hall is trying to say is that all the advantage comes in the adaptation period. He’s saying there isn’t any advantage in the long term.

    His graphs say that the advantage decreases by the end of the month to about 50 kcal/day – presumably in the metabolic chamber – which is statistically indistinguishable from zero. So his position is that, since it’s statistically indistinguishable from zero, it actually is zero.

    Two problems with this, but they aren’t as severe as you are saying. First, clearly the null hypothesis is incorrect for the transition period, which we, although perhaps not he, know as the period of gluconeogenesis during adaptation to ketosis. Second, while the level of advantage after a month is statistically indistinguishable from zero – and thus the null hypothesis is not disproven in the long term after full adaptation to ketosis – that conclusion has to be provisional, since the alternative hypothesis hasn’t been disproven either.

    What NuSi needs to do is to insist that the next study have enough power to resolve a 50 kcal/day advantage from zero, as well as fix the other problems you note.

    • One of the problems is that the doubly labeled water part of the study isn’t shown in the poster, yet is mentioned in the abstract. We know that the DLW part was done during the out-of-chamber days, but we don’t know when. Was it all through the study? Was it at the first part? Was it near the end? Based on the invidious way Hall explained the study, it makes me think it was maybe toward the end, but that’s just a guess. If it was done near the end, then it might show a more prolonged increase because the numbers for the DLW part were the highest of all.

      The other interesting part about this study that I didn’t include because the post was taking on the dimensions of War and Peace was how this study – the parts shown, at least – is so opposite what is normally seen in weight loss studies. Typically over a two month period, one would see the fat loss falling off dramatically during the last month as compared to the first month – that’s how weight loss works. But in this case, it’s just the opposite. Weight loss actually increased during the time virtually all weight loss studies show a decrease, which makes the increased loss even more significant than simply the numbers would indicate.

      As to your last point, I’m sure the next study or studies will be of longer duration with more subjects. The Hall study was simply a pilot study to prove concept and power.

      • So basically if the periods were reversed the outcome could have been dramatically different again – speculation of much more dramatic losses on the LCHF part if that was the first intervention, then possible slowing, stalling, or even brief gains once going to HCLF and re-carb-adapting before further losses.


        • Maybe. I would bet it that way, but we don’t know because it wasn’t done. If we had the graph for the doubly labeled water part, we might see a different picture. I’m wondering why Hall didn’t put that one up.

  24. I only know for a fact! After I read and followed Protein Power sometime after your 1st book came out…..I lost 38pds. Thanks to you my cholesterol is finally under control!!! I believe they could be dead wrong!!!!!

  25. “They are afflicted with the confirmation bias themselves”

    The study involved a randomized controlled trial in a metabolic ward. Good grief! Did you take statistics in college?

    • Hey Charles, I thought I had you blocked. Must have been removed when I redid the site.

      I’ll remedy that now.

      And, no, I didn’t take statistics in college. I learned it via OJT. You?

  26. As I listened to the video and noted the charts, he was reporting the results of post meal O2 emission as so many KCal per day,

    However, post prandial results generally show a rise to a maximum and a fall over several hours. It is possible that they took the measurements and did the integration over the peak, but I don’t recall this being described. There are several way of misconstruing or misrepresenting such data.

    So, it seems as if we must wait for the paper.

  27. It’s appears we have one study with two seemingly contradictory conclusions: on the one hand there is an increase in energy expenditure of 100 calories a day. On the other hand, according to the poster, there is no supplementary fat loss. So where does the metabolic advantage come from? Is it possible that it’s not coming from fat but from the breakdown of muscle? Insulin also blocks gluconeogenesis and muscle breakdown. So with low insulin levels the energy in muscle is freed also. Is that what is happening here?

    • There are many questions left unanswered on this study. I’m hoping the final, peer-reviewed paper will answer them.

  28. Thanks for the great post.

    Just wanted to note that they also restricted the amount of easily accessible exercise possible. This means that if the subjects had felt more energy in the high fat phase due to reducing cellular starvation they would have had little opportunity.

  29. I was mostly shocked how easily he dismissed the appetite control quality of a LC diet on grounds that “no one would want to live like that”. Ha! The longer you follow such diet, the easier it gets.
    Personally, I don’t care much about the famous “calories advantage” because most people are not good in counting calories, me included.

    • Yes, I was amused too. Bacon and eggs for breakfast, steak for dinner, butter on your asparagus, strawberries and cream for dessert … absolute torture!

        • It can take a long time to cease to become carb addicted. I think Gary Taubes estimated well over a year, and I think for many people (including me), it’s longer than that.

      • Yup it’s a hard life. I normally start the day with a buttered oatcake (5 – 6g carbs) with smoked salmon then go anything from 5 – 8 hours and often 10 hours or more without even thinking about eating, then I have a LCHF meal any time from late afternoon to late evening, and maybe a snack (sometimes another meal) at night.

        It was soooo much easier when I started the day with a bowl of muesli and low fat milk and was starving again a few hours later, and had to carry a whole bunch of carbs whenever I went on a long walk to avoid falling over after a few hours.

  30. Hi Dr. Eades,

    It is all nonsense. Anything, including astrology , can be dressed up in the cloak of science with graphs and correlations and statistics, as Paul Lutus brilliantly points out. No explanations are provided, none even attempted. The “science” in the nutritional field is appallingly bad! This Dr. Kevin Hall guy cannot even get it right mechanistically. Calories CANNOT POSSIBLY MORPH INTO TISSUE. Calories quite literally have NOTHING to do with causal mechanisms behind how humans gain tissue. It is about C-A-R-B-O-N ATOMS. The calorie theory is as wrong as wrong gets. It offers no explanation for obesity whatdoever, does not even rise to the level of being called a theory due to this… And it gets it all wrong mechanistically. Energy is ONLY A CONCEPT, A PROPERTY, AN ABSTRACTION. Nothing more. Even in quantum field theory we cannot dustitute the word energy for matter. They are as different as heaven and giraffes.

    Kevin Hall and a host of other scientist are laughable jokes. Calories are NOT ANYTHING themselves because energy is NOT ANYTHING itself. There is no such thing as an ” essence of energy.”

    It is FAR too soon to tell if the insulin idea is wrong. At least it is a theory and offers explanation. Hall cannot differentiate between energy and fuel . Fuel is STUFF-MATTER. Energy is a CONCEPT. “Energy” NOT A THING AT ALL . Rather, mathematical abstraction.

    We need many techniques used and replication to falsify the insulin theory.

    Dr. Eades: Murrsy Gell-Mann had an elegant theory which disagreed with SEVEN experiments. Guess what? It turned out Gell-Mann(and his colleagues) was RIGHT, the experiments-all seven -were allllll WRONG. Gell-Mann always notes this in lectures. Bring this up to Hall.

    Atoms can survive Supernova explosions where temperatures reach 160 BILLION F. Bodily human fat tissue is matter, made of atoms. Fat tissue cannot be melted off. Atoms cannot be burned off or burned away. More fitness blogger nonsense. It would tske at least 100 million degrees F. for quarks to leak out of protons…..

    Calories have NOTHING to do with how we gain and lose muscle and fat. Nothing….. Carbon atoms do. Plus a whole lot of complex partitioning of the food (matter-carbon) and complex biochemistry.

    His study is not probing unknowns. Science is held back by only studying knowns. This Hall guy has not even remotely shed better light on understanding obesity. He is a very poor scientist who cannot sketch the relationship between the knowns and unknowns, which is essential to even remotely grasp science. The scientific enterprise searches for deep explanation, NOT just descriptions. This is the reason we understand seasons for instsnce.

    “Calorie counting ” or CONCEPT COUNTING IS NOT the way forward. The way forward is further work into not just gut flora, but viruses and microorganisms, genetics and learning how fat cells ACTUALLY WORK, THEN INTERVENING BIOCHEMICALLY.

    By all means, spread my info around. Anyone is free to use it. Educate Dr. Hall, CarbSane and others.

    Lyle McDonald, Colpo, CarbSane-all scammers. They are total science denial for profit and prey on very green and gullible people. I was that gullible person back in 2006. These days I have far surpassed these scam artists.

    Compared to Einstein, Lorentz, Feynman even Willet and Hu are tools.

  31. Chewing through the numbers, I note that the reported RQ didn’t drop as much as the FQ, in other words they were oxidising more carbs than they were being fed. All the numbers aren’t there, but I calculated that in the keto period they burned the fat the ate almost to a gram, plus some carbs they didn’t (glycogen ?).

    In the 14 day run-in period they burned both fat and carbs that they didn’t eat, thereby losing weight when it was supposed to be eucaloric.

  32. Hi ALL, : )

    I forgot to add this, if I may, answering some commenters’ questions:

    With regard to the gain and loss of bodily fat tissue and muscle tissue OVERALL (NOT specific-just talking the gain of bodily tissue of ANY sort or type))it ultimately is about total carbon atom flow. Carbon atom flow IS the (Real) physics! You can VERIFY this. Carbon Atoms, NOT, NOT calories. Honestky, “calories” are not at all the causal mechanism and literally have nothing to do with the process. Heat and energy are fundamentally DIFRERENT things. Not a single “caloroe ” in history EVER, EVER, EVER went on to morph into orbecome MATTER, FAT TISSUE. IMPOSSIBLE!

    EVERYONE should habe a read of Prof Matt Strassler’s a Harvard physicist, article about energy and matter. Mass is DIFFERENT from matter. Energy and mass are NOT things. They both are properties. I had some dopey doctors throw E=MC2 at me… Laughable! Not even remotely what it means. E=MC2 deals with MASS, AN ABSTRACTION. Mass is the measure of the energy of a body at rest. TAHT is what E=MC2 means. Energy and MATTER are as different as heaven and giraffes.Matter does NOT turn into energy and vice versa! So many people hijacking science!

    It is a unit conversion equation. Kilometers to miles etc. as an analogy. The distance was always the same.

    Heat is NOT energy. Heat HAS this abstract quality we call energy. Huge difference. Jiggling atoms heating water are NOT energy! They HAVE, jiggling atoms HAVE energy. Calories are not A-N-Y-T-H-I-N-G themselves. The atoms ehich are jiggling from the fire excite the container holding the water causing it to heat up. Big whopptie do! Calories are an ABSTRACTION. NOBODY eats them! Feynman was very clear about this.

    Somebody asked what a calorie was. It is a unit of energy. Energy has many ridiculous units according to the late Feynman. Totally unnecessary. Energy itself, is not anything. Energy is merely a property. What isma calorie? An abstract concept…… Nothing in and of itself!

    Despite what is often said, heat is NOT energy. Energy is merely a property, the conserved mathematical quantitiy (Number) in time symmetric Lagrangians. And in the case of the expanding universe? Energy is NOT conserved. We already live in a universe where energy is NOT always conserved. Cosmically, it is not respected, only locally!

    It is more complicated as far as fuel (which is MATTER, a real thing, NOT energy) PARTITIONING. It is very possible the various chemical compou ds in food affect PARTITIONING and why it is easier for some to gain all muscle. Other fsctors beyond food count. We need to look deeper into genetics and the molecular level of understanding (genes CAN change in 25 years as Dr. Jeffrey Friedman stresses)

    Fat tissue C-A-N-N-O-T be burmed off, melted away or burned up. All ofmthose UEED CARBON ATOMS of the fat remain, keeping you heavier. Calories have NOTHING to do with how we lose bodily tissue, fat tissue etc. Carbon atom flow, with advanced biochemistry and partitioning etc. It is complicated.

    But if Arnold wanted to gain more muscle ingestion of more carbon from food is necessary, but this EXPLAINS NOTHING about ehy obese people overstore lipids! Nothing!

    Poor, poor, poor, poor science in the nutritional fields…….

  33. You’d hope that, after so many exposés of people “finding” something different from what the data says, a researcher would be more careful in these Internet-led days. Or maybe he’s convinced himself – but what about his colleagues?

    I’ve just been reading Jason Fung’s amusing item about how not to write a diet book, here.

    Do we await the KH one with(out) bated breath?

  34. Dear Michael,
    Thank you for this wonderful article. Now, I wonder if we are able to really measure all relevant facts using the chamber as it is? The chamber is obviously measuring the calories/heat.We start disputing CICO concept, yet ending up measuring calories. Could it be that we cannot see the whole reality while adhering to the plain energy measuring concept? Could it be that certain energy may be hidden in the form of chemical processes, so that we cannot observe it just by watching the real time energy expenditure. The reality of high fat low carb diet is so convincing that it almost doesn’t matter what happened in the chamber with the heat (calorie inclined) measuring technology.

  35. Regarding the delta-fat chart: The dash line seems to supports his claim since the rate of fat loss at the end equals the rate before.
    However, besides having only 4 points, there is something even more disturbing to me: There are error bars only on the LC phase, we can’t see them on the HC phase.
    If the error bars on the HC phase also touch zero like those on the LC, then what the chart basically says is that the measurements of fat loss are not sensitive enough,
    or that the sample is too small (I don’t know if the error bars indicate measurement errors or the value distribution over subjects).
    So the fat-loss chart could be totally meaningless.

    The EE, SEE and insulin charts do seem to support his claim, it shows that the EE rise is a transient, and although it has only the chamber measurements,
    the comparison is valid: chamber-LC vs chamber-HC, and the insulin measurements are on the same days.

    I would very much appreciate if you could explain a remark you’ve made which I totally don’t understand: “fat is lost in feces”.
    To the best of my knowledge fat oxidation waste products are the same as sugar, namely water and carbon dioxide. And even disregarding the composition, fat loss is metabolism, i.e “calories out”, it is unrelated to the digestive process, so
    what feces has to do with it?
    I believe feces can indicate on “calories in” only.

    You didn’t write about the RQ chart. Can we deduce anything from it?
    After reading Wikipedia entry on RQ, I understand that the lower RQ indicates fat-burning,
    but can we discern from the numbers whether it is fat tissue or just the fat intake?

    • Fat can be lost via the feces. In fact, a small percentage of fat always makes it through and is lost. I think I was speaking about ketones in the post. At least I meant to be. Since ketones are water soluble, they can make it into the stool and be lost. And since ketones are about 5 kcal/g, losing just a few grams can run the calories out up.

      It’s hard to deduce a lot from the RQ chart other than more fat is being burned in the second part of the study than in the first, which would be expected. It would have been nice had the authors provided us with the actual RQ numbers instead of the way they did it, which was to show the drop in RQ. Usually in a mixed diet the RQ is ~8.5-8.9 depending upon carb levels. In a high fat diet it drops closer to 7.

  36. Hi Mihailo, : )

    I know your question is to Dr. Eades, but I think I can help and offer detailed unique insight. I have asked this very same question to genuises and found my answer over 8 years. I think you will find it interesting.

    There is no scientist that I ever communicated with who could even give me a rough draft of the many, many hellishly complicated equationS that would entail applying conservation of energy to a human body. This is the most extreme and difficult of tasks. This tallying of total energy would HAVE to include the confined kinetic energy of quarks and gluons. You will never hear a huckster mention this because this is real science. Look into asymptotic freedom. In THEORY it may be possible. But, in reality? Likely not.

    All conservation of energy means is this: “There is a quantity, a number , that physicists can calculate which does not change when Nature goes through its manifold changes.” A decrease in energy is every bit the “violation” of this principle as an increase is….

    Ignore the CarbSane et al types. They are all physics illiterate. They are improperly using this principle. The exolanation above is directly from the late physicust Richard Feynman himself.

    Keep in mind energy is NOT stuff, just an abstract property OF things (matter). Energy is not what adds fat tissue to our bodies. Matter does that-carbon atoms. Also keep in mind “heat” is NOT energy. Heat HAS energy. They are fundamentally very different things. The entire caloric idea represents extremely poor science. Setting food on fire does not even remotely similar cellular respiration , which is extremely selective to the maximum, unlike fire, which is wild indiscriminate burning. Fire is not energy. Fire is a cloud of hot particles that has the property of energy. The human body and metabolism operates like a super complex chemical cascade . The electromagnetic force governs all of biology.

    The random irregular motions of atoms is reponsible for heat, jiggling atoms, as Richard Feynman explained. How this has anything to do with the excretion of carbon atoms, which IS necessary for fat loss, is beyond me….

    Hope this helps.

    Very Respectfully,

  37. This may not be the right place for my observations but…. the problem I have with LC diets is that they are known to lower conversion of T4 to T3 which could possibly result in a permanently lowered metabolism. Another thing is that there are many slim & healthy populations in the world who consume large amounts of carbohydrate, e.g. Japan, but there are many others. How can we claim that a LC diet is the healthiest? I’ve tried LC dieting and have uncontrollable carb cravings the entire time. Many would say that my body is trying to tell me something… it needs more carbs. Why do men crave more protein in their diets than women, because they have more muscle mass. I don’t think we can discount what cravings mean.

    • The notion that low-carb diets impair the conversion of T3 to T4 is a controversial subject and far from confirmed. I’ve taken care of many thousands of patients on low-carb diets and monitored their thyroid status closely. A fall off in thyroid function was no more common in my patients than in the general population of patients.

      There are healthy populations the world over who consume plenty of carbs and don’t seem to show any ill effects from it. The Japanese are one such society, but the Japanese in a strange case in that they, among populations, have great longevity, yet they smoke more than any other industrialized people. Does that mean smoking is a healthful activity since the Japanese do it and have great comparative longevity? I don’t think so, but it’s the same rationale as saying it about carbs. We don’t know how long the Japanese would live if they didn’t smoke, and we don’t know how much healthier they would be, if at all, if they ditched the carbs. We do know from RTC in the Chinese that they improve when they reduce their carb intake, but I haven’t seen the same studies in the Japanese.

  38. All I have to say about your post is, “Exactly!!” I was listening to that youtube interview while looking at the graphs and going, “what? insulin is down, weight loss is improved, EE is up, what are you talking about?!”

    Plus, this study wasn’t any longer than Ludwig, IIRC. It seems like the only difference was Subjects spent two days a week in the met ward? Where they expended less kcals than in the wild. I haven’t seen the study published yet, but I’m looking forward to it.

    In the meantime, thanks for confirming I wasn’t nuts for yelling at my computer during that vid.

  39. Hi, just looking at the science as i see it:

    1. I agree, it seems as though fat mass does resume dropping after the initial slow down, however, it seems to be the same as the carbohydrate diet – does this mean that the reduction in calories is more responsible for fat loss than what you eat? It seems as though they both do the same.

    2. Bodyweight loss seems to slow down in the last 4 weeks and doesn’t have the same rate of loss as the initial carb diet. What does this suggest? My initial thoughts is that the body is keeping muscle and shedding fat

    3. If you look at the first and last data points on the energy expenditure graphs, there’s not much difference and the fat diet is trending down – so the study wasn’t long enough. Conversely the carb diet was trending up just before the switch over. Actually if you look at all the graphs theres not many data taken at the diet switchover – thats odd to me.

    4. I think an 80% carb and 5% fat diet would have been the better case to contrast. I don’t see why you use a 35% fat diet?

  40. Tolstoy: “I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it be such as would oblige them to admit the falsity of conclusions which they have delighted in explaining to colleagues, which they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives.”

  41. Welcome back! I was getting worried that the prolonged silence meant She With The Wadded Panties had eaten your liver with fava beans and a nice chianti.

    Well I did see you on Diet Doctor and an Australian blog.

    Meantime I took the opportunity to re-read a bunch of your classic posts. I thought this

    was poignant considering it was seven years ago. What has happened in the meantime? Well there must now be thousands of well controlled diabetics, people who have lost scads of weight and controlled other metabolic problems. There need to be MILLIONS.

    There are now dozens (maybe hundreds) of LC-friendly doctors and nurses. There need to be thousands.

    There are hundreds of researchers who start from the premise that low fat diets didn’t work, and are looking into why and what to do instead.

    Then there are more and more studies, like this and Kevin Hall’s earlier magnum opus, financed by the bottomless pit of money backing Conventional Wisdom. I spot a considerable amount of desperation in the techniques used and the statistical manipulations employed.

    All power to you, and a small but increasing number of other clueful bloggers, for dismantling them.

    • Thanks for the great comment. You made my day. I hope I never let She With The Wadded Panties get near enough to me to eat anything. And thanks for linking to that old post – I had forgotten I had even written it.

  42. M’aider. I’ve been so happy for so many years with my meat/fat/spices/water regimen. No fiber. Last night, I spent hours reading and listening to Justin Sonnenburg and I’m wondering whether it’s time for me to change my ways. Have you discussed his research? I need your analysis/input. I’m probably your oldest groupie (83 on May 2 and having a great life).

    • If you’re having a great life, why change? If you increase your fiber, you’ll convert it to short chain fatty acids in the colon, and the cells lining the colon will be happy. Or you could eat some butter, which contains short chain fatty acids, some of which will make it to the colon where they will be eaten by the cells lining the colon. And those cells will be happy.

      If you want to add some fiber, you can always take a fiber supplement. But if everything is moving along okay, why tinker with success?