Are we meat eaters or vegetarians? Part III

A little over two years ago I wrote a couple of posts arguing that we cut our ancestral teeth on meat, and that contrary to all the vegetarian blather about colon length, tooth structure, etc., the archeological and anthropological convincingly demonstrates we were descended from meat eaters, not vegetarians.  (Click here and here for those posts.) A couple of recent developments have now inspired me to write a third.

First, I noticed in both talking with people at the Ancestral Health Symposium last August and attending a number of the talks that many followers of their own version of the ancestral diet are dismayingly including more and more carbohydrates.  And recommending more to their followers.

When MD and I wrote Protein Power in the mid 1990s, we used the Paleolithic diet as an argument for the efficacy of the low-carb diet.  If pre-agricultural man evolved in a milieu devoid of carbohydrate-dense foods, we posited, then natural selection should have culled those who didn’t thrive on such fare, leaving us, the descendants, powered by metabolic processes that performed better on protein and fat substrates.  If the rampant obesity and diabetes (we just thought it was rampant then) was a consequence of a diet we weren’t designed for, then switching to one that better suited us metabolically should produce substantial changes to the good.  Which it undeniably does.

I can’t help but recall the great quote by Dr. Blake Donaldson, who changed the complexion of his practice in New York after spending some time with Vilhjalmur Stefansson.  Wrote Dr. Donaldson in Strong Medicine, his book about an almost all meat diet:

During the millions of years that our ancestors lived by hunting, every weakling who could not maintain perfect health on fresh meat and water was bred out.

Now, it seems, many who have taken to the Paleo diet have started to drift from the Paleo-is-basically-low-carb paradigm into the Paleo-is-anything-that-isn’t-Neolithic paradigm.  And although Neolithic man grew all sorts of crops, most Paleo dieters consider only grains to be truly Neolithic foods.  Some Paleo dieters take it a step further and argue that since pre-agricultural man couldn’t have domesticated animals (other than perhaps canids of some sort), then he couldn’t have eaten dairy products.  So, those Paleo purists avoid grain and dairy products.  Both the dairy and non-dairy Paleo dieters, however, are starting to include larger amounts of carbohydrates – primarily starch – into their diets on the presumption that Paleo man would have eaten it.

I have no doubt that Paleo man would have been face down in a box of donuts had he been given the opportunity.  But he wasn’t.  Nor was he often presented with the opportunity to indulge in a carb fest composed of high-starch fruits and vegetables. Maybe in the fall when the fruit ripened (if he could beat the birds and bugs to it), but not much of a chance during the rest of the year.

(I am aware that Denise Minger put up a post not too long ago showing all the high-starch, high-sugar tropical fruits available in tropical areas, intimating that early man must have consumed these and, therefore, should have evolved to do okay on high-carb diets.  Problem with this reasoning is that archaic homo sapiens migrated out of tropical areas anywhere from 60,000 to 150,000 years ago and went through the crucible of natural selection in other less fruit-laden climes.  People of European descent certainly had ancestors who could not avail themselves of tropical fruits at any time.)

The second event driving me to write is a line out of a guest post on Richard Nikoley’s Free the Animal blog by Darrin Carlson titled “The Five Failings of Paleo.”  In Mr. Carlson’s own words, here is Paleo Fail #1:

We Don’t REALLY Know What Our Ancestors Ate. [Bold and caps in the original.]

I disagree for a couple of reasons.  First, we can be pretty certain what our European ancestors didn’t eat.  They didn’t eat dwarf wheat, Red Delicious apples, bananas, Bartlett pears or any other hybridized or tropical fruits commonly available today. As far as we know, there were no Paleo Luther Burbanks grafting and hybridizing plants to make them bigger and sweeter.  Our predecessors would have eaten whatever plant foods were at hand, which is pretty much what you still find if you go out in the woods today. They would have had to battle the birds and other wildlife to get to these fruits, and would have had them available only seasonally.

The second reason I disagree is alluded to in a way by Mr. Carlson in his explanation of Fail #1: Said he:

We have yet to find a magic phone booth that will transfer us back through time–Bill and Ted notwithstanding–to directly observe how our great-times-450-grandparents lived.

Actually we do have such a ‘magic phone booth’ available to us, or at least to those of us who know how to use it.  It’s an isotope ratio mass spectrometer, and its use has been refined over the past 30-40 years to allow us to peer back in time and calculate what our ancestors ate.

I learned about this ‘magic phone booth’ in the fall of 2000 in Hamburg, Germany where MD and I attended a great conference titled Meat and Nutrition.  After the last talk, on a cold, dreary, foggy, drizzly afternoon, MD, Loren Cordain and I lit out to  make a pilgrimage to Indra and the Kaiserkeller, the dives where the Beatles had gotten their start in the early 1960s.  We asked Michael Richards, a professor at the University of Bradford to join us.  On the first morning of the meeting, Michael had given a riveting talk on the use of stable isotopes to determine the diet of early man, and I wanted to find out more.

After roaming the Beatles early haunts, we decamped to a Hamburg coffee house to get warm.  I asked many questions about the stable isotope methodology and have followed the growing literature on it since.  Michael has turned into an academic superstar and is now at the prestigious Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, where he continues to publish his work on the isotopic analysis of the diet of early man.

Let’s take a look at the ‘magic phone booth’ of stable isotope analysis and see what it shows.  The whole notion is fairly complex so I’m torn between making its science simple enough for Homer Simpson to understand, which really doesn’t do the technique justice, or making it unnecessarily difficult. I’m shooting for something in between.

As most everyone knows, atoms are composed of protons, electrons and neutrons.  The number of protons gives an element its atomic number.  A given element always has the same number of protons but can have varying numbers of neutrons.  Carbon, for example, has six protons (and an atomic number of 6).  But the carbon atom can have 6, 7 or 8 neutrons.  All three versions are still carbon, but the atoms vary by the number of neutrons.  These different versions are called isotopes, so basically isotopes are atoms of the same element with the same number of protons but differing numbers of neutrons.  The atomic mass of an atom is determined by the number of protons and neutrons it contains, so although carbon always carries the atomic number of 6, carbon has three different atomic masses: 12C, 13C and 14C.

Carbons with an atomic mass of 12 and 13 (12C, 13C) are stable whereas 14C (pronounced carbon 14) disintegrates radioactively over time.  This radioactive decay is what allows scientists to determine the age of organic materials up to about 40,000 years old. The discovery of natural radioactivity of 14C and its usefulness in determining age garnered Willard Libby the 1960 Nobel Prize in Chemistry.  Although the unstable isotopes such as 14C have their uses, we are concerned here with the stable isotopes.  Primarily 12C and 13C and 14N and 15N (nitrogen 14 and 15).  From these four stable isotopes, we can learn a lot about the diet of early man.

Nuclear weapons started adding 14C into the atmosphere in the mid 1900s, so the average ratio of 12C, 13C and 14C have change slightly.   Since 12C and 13C are stable, there has been virtually no change in the ratio between them over time.  But the ratio of the two has been found to differ from one carbon-containing material to another.  For instance, carbon dioxide generated from marine limestone contains more 13C than does carbon dioxide generated from burning wood.  In general, marine sources have greater amounts of 13C than do terrestrial sources.

Just to make it a little more complex, when researchers run samples through a mass spectrometer to determine the 13C/12C ratio, this ratio is compared to an agreed standard.  Then the difference between the sample and the standard is called the relative 13C content, which is designated by δ13C and measured in parts per thousand. (‰)  So if the sample has a ratio less than the standard by 5 parts per thousand, it is defined as having a δ13C value of −5‰.

Don’t worry about all the above – just remember when you see δ13C from now on, it refers to the ratio of 13C to 12C.  Don’t despair.  It will be easier as we go along.

Of the dry weight of bone, a little over 25 percent is collagen, and it is collagen that is the tissue of choice for stable isotope analysis.  Virtually all of the carbon and nitrogen in collagen comes from protein, and since most protein in the human body ultimately comes from protein in the diet, the carbon and nitrogen isotopes in the collagen reflect the protein sources in the diet.  And since the stable isotope composition of collagen turns over very slowly, the ratios of carbon and nitrogen stable isotopes reflect diet over about an eight to ten year period.

Stable isotopes of both carbon and nitrogen occur in varying proportions in different foods, and these proportions are passed along to the animals, including humans, that ate these foods.  By knowing the proportions of the stable isotopes in various foods, we can determine these foods by analyzing the stable isotopes in human collagen.

Researchers are able to extract valuable data from the collagen of ancient bones.  Unfortunately ancient bones are not thick on the ground, and since a part of the bone has to be destroyed to perform the stable isotope analysis, these analyses are not done by the thousands.  Each time a skeleton or group of skeletons is unearthed, Michael Richards and other stable isotope researchers try to snare a little piece of bone and go at it with the mass spectrometer.  This kind of work has been done for several decades now, and the results – though painstakingly obtained one specimen at a time – are accumulating, and there is now a fairly substantial body of data.  And this data is remarkably uniform in what it shows of the dietary habits of our ancient European ancestors.

The δ13C and δ15N figures reveal different information about the diet of Paleo man.  Since the 13C isotope is found in greater quantities in the marine environment than in the terrestrial, a larger δ13C indicates a diet higher in seafood protein whereas a lower δ13C is associated with a diet composed primarily of protein foods from the land.  Researchers have accumulated considerable data on the δ13C of seals and other such animals that spend their lives in the oceans consuming other marine life to compare with the data gleaned from bones of animals living on the land far from the sea.  By noting how the δ13C from ancient human bone compares to these extremes determines whether the human dined on protein from terrestrial or marine sources of from a combination of the two.

The δ15N tells a different story.  δ15N basically tells us where an animal or human is on the food chain.  Basic plant foods maintain a fairly constant δ15N value.  When animals, typically herbivores, eat these plant foods, the stable N isotope in the plant food tends to concentrate by anywhere from 5-8 percent in the collagen of the animal.  So if the collagen of an animal is found to have, say, a 7 percent greater δ15N than the local flora, one can say the animal was an herbivore.  Animals that are known herbivores, when analyzed, fit this spectrum.

Any animal, including man, that dines on herbivores will have collagen sporting a δ15N that is about 7 percent greater than that found in the herbivores that are the meal, a fact confirmed by stable isotope analysis of known carnivores.  A super carnivore (for lack of a better name) that dines on other carnivores and herbivores would have an even greater δ15N level.

So, δ15N pinpoints us on the food chain while δ13C tells us whether the protein we eat is surf or turf or both.

Now that we have a full understanding of the ‘magic phone booth’ of stable isotope analysis, let’s take a look at what the data show.

The data taken as a whole show the following:

Early man was a high-level carnivore. (As was his distant relative the Neanderthal, who lived contemporaneously with ancient man in Europe.)  A higher-level carnivore, in fact, than foxes, wolves and other known carnivores.  The earliest anatomically modern humans got most of their protein from animals of terrestrial origin.  As time passed and the populations of large game thinned due to heavy hunting by both humans and Neanderthals, the human position on the food chain didn’t change, but sources of protein changed from all terrestrial to more and more marine (which includes fresh water fish, mussels, clams, etc., all of which have a similar δ13C as animals from the ocean).  Irrespective of whether the protein came from the land or the sea, early man occupied a super-carnivore niche in pre-agricultural days.

Here are a couple of graphics of stable isotope studies done by Michael Richards – one on Neanderthals; the other on early modern man – I presented at the Ancestral Health Symposium back in August at UCLA.

As you can see from this slide, the Neanderthal subjects were ranked a bit above the wolf and fox on the predator/meat eating scale.  As Michael Richards commented in the paper cited above:

…the European Neanderthal diet indicates that although physiologically they were presumably omnivores, they behaved as carnivores, with animal protein being the main source of dietary protein.

When we take a look at another study evaluating ancient humans, we see much the same thing.

As compared to the Arctic fox, you can see that early humans were way off the chart to the right.  Michael Richard’s commentary:

We were testing the hypothesis that these humans had a mainly hunting economy, and therefore a diet high in animal protein.  We found this to be the case…

The bulk of the stable isotope studies show both Neanderthals and ancient humans were, at their robust cores, meat eaters to the max.  What the stable isotope studies don’t show, is how much carbohydrate these folks ate along with their meat.  (Actually some stable isotope studies do show what kind of carbs in the sense that they can differentiate between grains and non-grains, but since there were no grains in Paleo times, that isn’t a concern.) But since we do know that wolves and foxes are predators that consume mainly food of animal origin, and we know that early humans have an even more carnivorous stable isotope footprint, it seems unlikely that these humans would have consumed many calories from non-animal sources.  Remember, natural sources of protein are virtually always associated with fat (copious amounts of fat if the protein is from large game and the entire carcass is consumed), so it’s doubtful there would be either the capacity or the necessity for complementing the basic diet of fat and protein with much carbohydrate.  But, nonetheless, even if our ancient ancestors did eat some carbs they could scrounge while in season, the stable isotope evidence clearly demonstrates they were not vegetarians.

If you would like to read more about stable isotope analysis for determination of the diet of early man, a good place to start is with the publications of Michael Richards.

Other good sources for basic information:

Katzenburg MA (2008) Stable isotope analysis: a tool for studying past diet, demography, and life history. In Katzenburg MA, Saunders SR (eds) Biological Anthropology of the Human Skeleton. (Hoboken, Wiley-Liss) 2nd Edition pp 413-441

Schoeninger MJ, DeNiro M (1984) Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals.  Geochim Cosmochim Acta 48:635-639.

Schoeninger MJ (1995) Stable isotope studies in human evolution. Evolutionary Anthropology 4(3): 83-98.

van der Merwe, NJ (1982) Carbon isotopes, photosynthesis, and archeology. American Scientist 70: 596-606.


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253 thoughts on “Are we meat eaters or vegetarians? Part III

  1. Thanks for the interesting writeup. I can’t help but feel that claims of vegetation eating by paleo man doesn’t pass the sniff test. Most above ground vegetables contain so few calories that their consumption is worthless from a survival perspective. The time required to gather a ‘big salad’ would be much better spent hunting, trapping, or fishing.

    It, too, amuses me that the same arguments Stefansson faced almost a century ago have resurfaced: ‘you need some carbohydrates in your diet to prevent X deficiency’. Of course, asked to prove how a ‘glucose deficiency’ is biologically possible, backtracking and tap dancing begins.

    • Paul Jaminet has decided it’s possible to have a glucose deficiency if you don’t eat enough glucose so that you can produce mucus for your GI tract. Mind you, he is aware of the phenomenon of gluconeogenesis but for some reason it hasn’t sunk in.

      • The Perfect Health Diet of Paul Jaminet is scientifically sound. His debate with Ron Rosedale shows he has done the research and knows what he’s talking about. I include starches in my diet and my lipid and glucose levels are perfect.

      • My problem with his argument – and as delineated in a post by Dr. Eades – is that the mucous produced by the GI tract is a defensive/reparative response to mechanical damage to the delicate cells lining the gut wall – often caused by the passage of indigestible dietary fibre.

        Therefore, if you do not eat the fibre, you do not need to secrete this mucous and do not need to consume any sources of glucose to add to what your body can synthesise endogenously.

          • Care to elaborate? You can’t just throw something like that out there without backing it up with some hard data!

        • Exactly. Jaminet’s idea that carbs are required for immune system function is hard to square with the experience of paleo dieters that they rarely get colds and other infections. It seems just as likely that the excessive mucus is a reaction to the immune system dysfunction that occurs when glucose displaces vitamin C in white blood cells and impair their operation.

  2. This is indeed great evidence of our carnivorous past. Yet it really tells us nothing about our consumption (or lack) of carbohydrates, so we’re left to draw inferences by comparing to other species, never mind how (un)reliable that can be. How about the observations that as we do have pepsin, all of us have also amilase in our saliva. Isn’t that clear and strong evidence for the consumption of carbohydrate? You paint a picture of scrounging, and having to compete for plant material and fruits, things that don’t even move, but of course, we had to compete even more fiercely for animal prey, not to mention the rich and easy source of calories from tubers, things that grow underground. I believe it’s a positive that Paleo is now veering more towards a macro-nutrient agnostic point of view, focusing more on avoiding clear problems rather than finding a mythical/magical formula that’s can’t work for everyone, because we all have different adaptations. That means also recognizing that we are still evolving, and that 10,000 years of agriculture, while not much compared to 2.5 million years, it’s also not nothing.

    • Carlos – I agree with you.

      What about the oh-so-famous Kitavans? Haven’t we established (via Weston A. Price Foundation) that white flour (gluten), white sugar, and heavily processed foods are the enemy and not necessarily starchy tubers?

      • The Kitavans live on islands and have to eat what’s there because it’s not very easy to migrate somewhere else when you’re out in the middle of the Pacific, especially now when nearly all land is privately owned and you could get arrested or worse for trespassing. It is the same pitfall faced by the few remaining forager tribes in Africa. Some of them actually have poor dentition now because the farmers took all the good hunting land and what’s left isn’t enough for full nourishment.

        (Something to think about in context of the fact that so many Paleo and low-carb eaters are pro-private land ownership. That works out great if you want to be a grain farmer, but you can’t plant an animal herd.)

        You also see similar in those uncontacted Amazon basin tribes down in Brazil. They can’t move, they can’t leave their area and follow the game because their legends tell them there are hostile people waiting out there to attack them. They went into the jungles in the first place because of the conquistadores and they have long memories. So they have to stay put and plant potatoes or similar.

        It’s poverty food. Don’t just hypothesize about this. Go to the USDA nutrition database and look up potatoes and sweet potatoes. Then look up beef liver. Tubers are not worth the work you put into them unless you have no other choice.

        • Dana – Regardless of what the USDA website says if the Kitavans are doing extremely well on their diet that’s all that matters. And according to Stephen Guyanet(sp?) (I think it was him), they are absent all the diseases that afflict modern man.

          WAPF does not specify macronutrient percentages. I’m not disputing the value of liver, nor advocating a vegetarian diet but even the late great Dr. Atkins did not recommend staying VLC for long.

        • Dana you are saying that the Kitavans are eating substandard food because that is all they get.

          But you ignored the real question which is if that food is bad why are they healthy, why don’t they have bad teeth. Why don’t they even know what a heart attack looks like. No Asthma, and they smoke a lot. The question was to explain their health despite their high carb diet if starch and sugars are bad.

          Nobody asked the explanation of why they have this diet. That is patently obvious, everybody eats what they get in their environment.

          • Looks like they eat just ones a day. For many people intermittent fasting will compensate for less than perfect macro-nutrient composition.

          • Galina, why do they eat only once a day, when they have plentiful food, and carbs cause hunger :-). Something somewhere is wrong no.

          • But the question is how are they able to eat only once a day. Wouldn’t a high starch consumption increase hunger as most people here think. I am pretty sure that it wasn’t because of food availability, as the islands have plenty of food. And even if there are periods of low foods why would they do it all year round. During harvest season wouldn’t they be eating constantly as the diet is very high in carbs.

        • Dana, I would note that carnivores maintain and defend hunting territories. That’s pretty much private land ownership – it just involves a lot more land per individual than agriculture.

        • Kitavans preferentially eat the fish and how come nobody ever brings up there astounding 41 year average life span and seeming inability to cope with infections when they are championed as proof of necessary starch?

      • The Kitavans are famers who grow tubers instead of grains. Given them “green revolution” tubers, petroleum based fertilizers, and a large, efficient industrial economy, and they’ll get diabetes on their tubers.

      • The Kitavans are a small isolated group. There is every reason to believe they have evolved to tolerate a high carbohydrate diet.

        Put a large group of westerners on that diet and see what happens to most of them.

        • Based on a snapshot of ancestral origins/bloodlines of “westerners” as they exist today, about 25% will experience no problems. The other 75% will eventually develop problems metabolizing glucose to varying degrees.

    • What’s your point Carols?

      What the amylase (not amilase) in our saliva suggests is that we did have to adapt to eat starchy foods like tubers. It does not mean, however, these foods are a good source of nutrition or something that we need to eat.

      Just because our bodies adapt and our physiology alters to be able to accept and deal with a foreign invader or lesser form of nutrition doesn’t mean that that foreign invader or lesser form of nutrition is good for us.

      • I don’t find the ‘amylase argument’ very convincing. Many animals, including carnivores, possess the gene for amylase and will express it with increasing intensity dependant on whether they are fed increasing amounts of carbohydrates. In larval stages, the European Sea Bass show high levels of amylase gene expression even before the mouth opening stage (therefore not yet feeding). These levels are only maintained when they are fed large amounts of carbohydrates but decreases significantly when they are allowed to eat their natural carnivorous diet.

        We all evolved from earlier, simpler lifeforms (including plant eaters) and much of the genetic code from those earlier lifeforms are preserved in their descendants (even carnivores), even when not expressed, but that fact says nothing about what their current optimal diet is or should be.

      • We may not “need” to eat starchy tubers but that doesn’t mean they are a bad source of nutrition or something that we shouldn’t eat. Again, what about those Kitavans? Something like 90% of their diet is sweet potatoes and they have no heart disease or diabetes…..

        Again, maybe the evil trio is white flour (gluten), white sugar, and highly processed foods.

        • You can’t possibly eat a diet of 90% sweet potatoes and expect to maintain the Kitavans’ level of good health in the long run. They also eat a lot of coconut and fish. I wouldn’t be surprised if with the latter they make a broth out of the bones, and possibly also consume the organs. I have not heard enough about what land animals, if any, they also eat. But the 90% sweet potatoes figure is ridiculous.

          I’m also suspicious that a lot of the argument on Kitavans is based on speculation, not science. Has anyone actually done autopsies on their people who have died? Has anyone actually taken samples of their foods and analyzed ingredient and nutritional content? Weston Price did the latter in the 1930s but who’s doing it now? I’m still seeing idiots claiming Mediterranean people are healthy because they eat vegetarian diets slathered in olive oil. Mediterranean people, with the exception of Jews and Muslims, eat PORK and LARD.

          • Probably, smoking and chewing betel are good stimulants and appetite suppressants. There are some speculations that nicotine helps in the fat mobilization from the adipose tissue. Devil is usually in details.

          • They eat one time a day, it suppose to make great difference. They also smoke and chew betel – could an effective appetite suppressant.

          • Likewise, I’d also be interested in how the Apolipoprotein E genotype is expressed in the Kitavan population.

            There is growing evidence that obesity is more prevalent in people who consume more:

            [1] carbohydrates and express ApoE3 alleles
            [2] fat and express ApoE4 alleles

            Given their carbohydrate consumption and generally good health, it would not surprise me if the Kitavans express more ApoE4 alleles.

          • I’m APO E4/E4, and starch makes me fat and lethargic. I’ve had wonky carbohydrate metabolism all my life; I don’t know if it’s reactive hypoglycemia, carbohydrate sensitivity, or what, but starchy food in sufficient quantity creates huge blood sugar swings and makes me voraciously hungry. Every time I try to add starch back into my diet on a regular basis, I start gaining unwanted weight. Who knows, maybe my 2.9% Neanderthal DNA trumps my double APO E4.

          • As you’re probably aware, ApoE4/E4s seem prone to all kinds of issues.

            ApoE4/E4s have a higher incidence of atherosclerosis, late-onset Alzheimers (increased amyloid production which breaks down forming plaques), cognitive dysfunction, cell membrane dysfunction, and immune system issues. The studies I’ve read don’t appear to control for macronutrient consumption, so can’t tell if it changes the outcome.

            ApoE4/E4s also tend to be poor statin responders. Not sure if that’s a benefit or deficit. 😉

            Inflammation tends to be persistently high in ApoE4/E4s.

            Perhaps exploring the underlying mechanisms that create the deficits described above might yield some solutions.

          • You may be interested in reading more about ApoE4 from Dr BG Animal Pharm
            I think the idea that ApoE4 is a genetic modification that enabled certain peoples to better survive in vitamin d deficient environments may be worth considering, as is the idea that perhaps MELATONIN is EVEN MORE IMPORTANT for ApoE4’s than Vitamin D3 is for others.
            Considering the impact of Apoe4 on Alzheimer’s incidence I wonder if those with Apoe4 may be best advised to concentrate as much on correcting melatonin deficiency as ensuring they are vitamin d replete.

          • Thanks, Ted. Dr. BG leaves me even more strongly convinced that my paleo-ish, lowish carb diet is the right approach for me, although the best evidence for that is eight years of normal weight, stable blood sugar, and vastly improved quality of life.

        • I agree with Dana – where did that 90% sweet potato figure materialise from?

          Ever since the Kitavans and their diets were first mentioned, their sweet potato consumption seems to have increased a few percentage points with each retelling! I bet it will soon reach 100% leaving no room whatsoever for the high saturated fat intake they supposedly also get from coconut consumption not to mention the fish!

          As to them being ‘disease-free’, this is a liberal interpretation of the actual studies done on them. What the researchers actually did was compare certain biomarkers or risk factors between Kitavans and Swedes, who had a high incidence of heart disease. Not surprisingly the Kitavans had lower levels of the ‘high risk’ biomarkers. This, in itself, doesn’t tell us a whole lot, since the biomarkers often regarded as being risk factors for heart disease, when elevated, are often not so significantly correlated after all when you critically look at all available studies, i.e., cholesterol.

          Aside from these biomarker comparisons, the only data that seems to be quoted in support for their remarkable health are the records of medical practitioners stationed in the islands who periodically treated or examined the islanders during the 1960s.

        • Laurel, you are confusing Kitavans with some other natives (I believe from south America). Kitavans eat a reasonably varied diet. They eat lots of fruits, and tubers, they also eat a large amount of coconuts. They are not entirely vegetarians, none are. They do eat some amount of fish and smaller animals that they have on the island. Majority of their diet comes from carbs but it is nowhere near 90% level. They do have a good amount of saturated fats from their coconuts. Fish/meat is a small part of their diet, but it is very regular. There largest staple would be either fruits or tubers. I am not sure which is the dominant part, both seem to be equally high. Coconut only follows the two major groups of food. And Smoking is their major past time.

      • > What’s your point Carlos?

        Good question. I guess to point out that while Dr. Mike sets out to offer convincing evidence of our non-vegetarian past, all very good, He then overreaches to try and infer a no-starch past, which from the stable isotope evidence presented, is simply non-infer-able. It is evidence of our consumption of animal protein, but it isn’t evidence that we did not consume starch. As you smartly pointed out in another comment, this would seem to suggest we (the omnivores) depended even more on meat than other obligate carnivores. I love my steak but I find that hard to swallow. There is no need to build this theatrical farce about having to scrounge for carbs, the point against vegetarianism is made, but it simply isn’t one against carbs.

        BTW, thanks to you and others for pointing out my typo, I was thinking in Spanish (amilasa vs. the English amylase)

        • Anthropological data is useful, but can not answer questions such as:

          1. What is the optimum diet for human health?
          2. What is the optimum diet for human longevity?
          3. Are diets 1 and 2 the same?
          4. Does the optimum diet change with age?
          5. At what levels of intake are carbs detrimental to human health?
          6. Does the answer to #5 depend on other factors such as micronutrient intake, level of physical activity, etc.?

          I think the increased acceptance of carbs is due to the problems of some of the low-carb arguments based on recent science. For example, the dire warning about high blood sugar causing AGE’s is simply incorrect/incomplete. See Chris Masterjohns recent blog post:

          “but we know so far that zinc and insulin increase the production of glyoxalase-1 (29). This suggests that zinc, insulin, and glutathione are critical components of our defense against dicarbonyls and the AGEs they produce.

          “We should note here that since oxidative stress depletes glutathione, these findings suggest that promoting our antioxidant defense system is important to defending ourselves against the ravages of AGEs, and that since this whole process occurs within the cell, this constitutes further evidence that most of the action is happening intracellularly.”

          • “Anthropological data is useful, but can not answer questions such as what is the optimum diet for human health?”

            I think many people get this back to front! We didn’t – nor cannot – choose ‘the optimal diet for [insert your preferred parameter here!]’. Rather the prevailing diet (for the longest period within our evolution as a species) decides how our genome is optimally expressed.

            For example (hypothetically), our early ancestors had a choice between eating food A or food B. Food A was essentially benign; that is, it did not cause any negative health consequences. Food B, however, had negative health consequences when consumed in any significant quantity. If we had chosen to persist in making food B a staple, the cumulative negative health consequences may have resulted in early mortality and limited procreation. That particular line would be ‘selected out’.

            Those eating predominately food A, however, would live longer, healthier lives and have greater opportunity to procreate and continue their line. Each generation would genetically and epigenetically become better suited to consuming and metabolising food A.

            So it is not diet choice, as such, but how the prevailing diet influenced our evolution that should be borne in mind. Hence, trying to determine what was the likely diet of our ancestors IS an important aspect of determining what an ‘optimal diet’ may be.

          • I agree to an extent; but there are many arguments to the contrary. For example, natural selection does nothing about post-child raising health. Natural selection can select for a generalist diet at the expense of long term health if it increases procreation.

            This is a fundamental limitation of anthropological approaches. They provide a starting point as to what is probably a healthy diet, but do not answer more specific diet and health questions.

          • Grandparents were important enough for menopause to appear. And being nomads, they’d have to be healthy enough to keep up.

    • We don’t just eat food for calories. Have you ever *been* in ketosis, though? The simple fact is that if you’re getting enough animal, and are not going crazy on starches or sugars, you just aren’t hungry. I’m curious why early humans would have been desperate to find starches buried underground when they wouldn’t exactly have been ravenous to begin with.

      Modern people who eat carb-heavy diets and especially those who fear ketosis will never understand this and they look to the Paleo past through that lens of not understanding.

      We don’t make a lot of amylase, by the way. Rats make much more.

      • Dana, I eat a lot of starch, in the form of rice. I have a portion control problem. When I am eating it is very difficult to stop unless I count. But hunger is not the problem, it used to be before I stopped eating vegetable oils and wheat. Now I have done 50 hour fasts without much trouble. I need not eat for a long periods of time. So by your definition I should be in ketosis, because only ketosis does that. I also get into ketosis from time to time, as you would if you get into a longer than 24 hours fast. Also sometimes I will not eat any carbs in a couple of meals. But I couldn’t say that I find my mental state in ketosis any different from my mental state after a high starch food. You are giving more credit to ketosis than it is worth it.

      • Dana, why would they even want to spend the energy to hunt animals if they do not feel hungry. How long do you fast? When do you start to feel hungry, how many days?

        Do you know what the gatherer part of hunter-gatherer did in their life?

        Hunting is not a very certain activity. Many times it fails. In very cold places you could store the kill for a very long time, which will allow you to fail many times, but still have some food left. Arctic dwellers still were hungry many times.

        This mode of operation is not possible in the hot and humid tropics. Meat goes bad only in a couple of days. You cannot dry it, because the air is not dry. You need something to tide over the days when hunt fails. Gatherers also do something you know. They search for root vegetables or fruits. Fruits in tropics are not berries, they are starch and sugar rich large fruits. Bananas, Pineapples, and other even bigger fruits are available in large quantities. And they can plant those very easily.

        There is no way that Hunter Gatherers in the Tropics were living on an exclusive meat diet. Its a very difficult diet to maintain in the tropics. None of the natives, even the advanced Masai cannot maintain it. Masai breed cows to even get close to a high reliance of meat. Their diet is also not very low carb due to their reliance on milk.

        I suspect that the reason why AMY1 genes started increasing around 200,000years ago, was because humans started to select plants with higher starchy fruits and tubers. There is a very large range of AMY1 gene copies, which would mean that the gene copies can come and go in a much shorter adaptation cycle.

        • @Anand, don’t forget that a significant, but often overlooked part of “gathering” is small animals: insects, eggs, shellfish (where available), molluscs, and reptiles/amphibians. These are not plants, clearly. Also, FYI, meat can be eaten safely even once it starts to “go bad” for quite a long time, although I agree that most hunting people used various ways to preserve the meat, depending on their locale. Organs, on the other hand, were consumed first and while still fresh; i.e., Nature’s multivitamins!

          • insects shellfish, molluscs and reptiles/amphibians are all very high in proteins. They need some fat or carbs to balance out. High protein cannot be sustained. Fat is very difficult to get in nature, except during particular seasons when animals have a lot of fat on them.

            Have you tried keeping meat safe in a hot and humid area? You need a lot of salt. Then this concoction can only be used as a pickle in small quantities with some starchy food. Yes people try these things to preserve the precious meat, but it is not a great thing when you want to make meat a staple.

            The point is not about nutrient content of meat. Its not like we need a huge amount of nutrients for sufficiently active people. The requirement for nutrient dense food is only for sedentary people. The micro-nutrient requirement does not go proportionately to energy requirement with increased activity. Excess nutrients if we did not evolve with them will cause problems. Check out how efficiently our body preserves B12. Would it be required on a high meat diet?

        • I wonder how carnivores manage in a hot climate, for example, what lions do for their food preservation? If group of lions survive, humans can do it to.
          Looking around while living in a hot climate, it is easy to imagine that in tropics it is easier to maintain diet on insects.

    • Adding a few more points in addition to Carlos.

      The data does not give the isotope information for present humans.
      According to this theory the present humans should be much lower than the other carnivores. Can we get the data to compare, whether this theory actually means anything? also what about the data for Bonobo’s and chimpanzees. Both are mostly vegetarians, where do they fall.

      It could be just defining the type of digestive systems. Humans digestive system is as simple as carnivores but with a twist, we can digest starch directly without use of bacteria. Also our digestive system may not utilize vegetarian protein sources for building collagen. We can’t say for sure till we have compared present humans and Mostly Vegetarian Apes.

      Another point is that high starch sources have very little protein. So yes we may still be eating a high starch diet but still getting most of our protein from meat sources.

      Third point is where have these samples been taken from. Whether from Tropical regions or temperate regions. All traditional populations in Tropical regions have been eating much less meat, compared to temperate regions. So is there a bias in the data?

      Finally why is it that 10,000years ago is too soon and 60,000years ago is not soon enough for adaptations? I would think 200,000years should be the breakpoint for homo-sapiens, and those people were living in tropical regions where there is plenty of starchy and sugary vegetables and fruits all year round. Animals are more difficult to get than fruits and vegetables. Why should we model the diet specifically around a northern European concept of paleolithic diet when not everybody has that origin.

      Also the Neanderthals teeth have been found to contain starch grains from boiled sorghum. How do we explain that? Do we just selectively ignore this information.

      The long standing questions that Very low carb proponents fail to explain is the presence of so many AMY1 gene copies, in humans when they have not supposedly evolved to eat starch. What about Kitavans is I guess a rhetorical question.

      A theory must explain ALL OF THE DATA. Not just try to prove the theory based on cherry picked information.

      In the last article about ETH (Expensive Tissue Hypothesis), I had asked the question why do carnivores have smaller brains than vegetarian apes. Obviously carnivores have simpler digestive systems compared to vegetarian apes. I had also given a solution that protein is not a cheap energy resource, because of its problem of thermogenesis. It wastes nearly 30% of the energy converting to glucose. Which makes it difficult to get extra energy for brain. In view of this fat and starch are both very efficient sources of energy, and will allow brain growth. It is not protein or animal meat that will allow this only higher fatty parts of the animal like organs or fat stores and brains and bone marrow. I had got no response to my query. I hope that this time I will get some responses.

      I understand though that for people from a European lineage, a European concept of paleolithic diet will be the best for recovery. But it still doesn’t make it THE concept of paleolithic diet. It is just one of the concepts. Paleolithic diet has a much wider range of diets than just the range for which Europeans are adapted to.

      • Reading through the last article, I realized that Dr.Eades is thinking that ETH still requires selection pressure to grow the brain. I think that’s not correct. If there is more energy available because of simplified digestive system and ease of obtaining energy, the neurons themselves will grow in number to accommodate the extra energy. The pressure to accommodate new neurons will create a selection pressure to create bigger skulls.

        Actually it will happen like this.
        Children will be born with varying sizes of skull (ofcourse the variation would be small). If there is extra energy, and there is extra space in the skull the neurons will grow to utilize that space. These children will be smarter than others and will have a survival advantage. Over a few generations the skull size and the brain will grow. More generations will be required to actually utilize the extra brain more efficiently.

        The crucial thing is extra energy, the selection pressure will develop automatically. Keeping this in mind if Carnivores actually had extra available energy they would have bigger brains. But they don’t which means there is not much energy available. Which points us to the only possible reason, the thermogenic effect of Protein. Carnivores need a lot of glycogen because they use a lot of burst energy during those hunts. This glycogen is produced from protein via gluconeogenesis where 30% of the energy goes waste. This reduces the efficiency of carnivores simplified digestive system by 30%. This is only slightly better than herbivores. Fruitarian Apes do much better, because of the high sugar content in the fruits which does not require any expensive conversion.

        Humans do even better by finding more fat, and cooking the starches and higher AMY1 copies to digest the starch much more easily.

      • Different plant foods have different levels of protein. Legumes have a lot. Fruit has very little. Tubers and grains are in between. The bone isotope data rules out legumes and rules out use of tubers and grains as staples.

        The starch grains on neanderthal teeth from Europe were most likely from roots – think carrots or onions – which don’t have enough calories to be a dietary staple, though they might have been a dietary supplement in hard times. This was, however, after the broad spectrum revolution.

        I believe lions and similar carnivores have large livers to more efficiently process lean meat and reduce the dependency on fat. This is perhaps why hunting cultures that use dogs keep the fat for the humans and give the excess lean to the dogs.

    • Even carnivores have amylase, which is needed to process the glycogen in muscle meat, if nothing else.

      Humans do have more copies of the amylase gene than most carnivores – and also than apes. Most likely the additional copy numbers occurred during the neolithic as a response to agriculture, just as lactase persistence was a response to dairying. That doesn’t mean starch is healthy, though – just that in agricultural cultures where starch is available, being able to process it can allow bare survival during famines.

  3. “So if the collagen of an animal is found to have, say, a 7 percent greater δ15N than the local fauna,”

    Did you mean the local flora?

    Thanks for description of this method.

  4. Thanks for posting this. Seeing the science makes me feel better about my diet when I find myself lacking the veggies from time to time.

    • Looking at the USDA nutrition database is what did that for me. Just looking at the nutritional content of an apple was appalling, no wordplay intended. You get some C and some folate but you get too much sugar alongside; it’s basically a wash. The sugar is going to compete with the vitamin C, too, as they use the same receptors. (Animals that can make their own vitamin C, which is most of them, make it from glucose.)

      • The point on vitamin C is very valid. One fact that was provided by the Denise Minger post that Dr. Eades refers to, and overlooked by many, is that those wild tropical fruits have an order of magnitude more vitamin C than domesticated fruits.

  5. Hey Mike.

    Glad a post at my place helped in part to get you motivated to both do a post and part three of this great series (if you haven’t already, you might want to edit those two previous posts with the link to part III).

    So, OK, how about optimality? Not that we can necessarily pinpoint it, but do you think there’s an argument to make that living through an ice age, or on the frozen tundra is potentially less optimal to health than living in more tropical regions with a wider variety of nutrition, not to mention regular sunlight?

    • Who knows? Early man migrated out of Africa where there was plenty of sunshine and a wider variation of nutrition. Why? But after the migration, he lived in northern latitudes for thousands of years (without going back), so Blake Donaldson’s quote I think says it all.

      • Excellent post – a long overdue response to the ridiculous claim that we cannot know what palaeolithic humans ate, therefore anything goes! As you point out, there is plenty of evidence out there, the weight of which would seem to confirm that palaeolithic man predominately ate meat.

        As to the migration out of Africa (which I believe occurred more than once), one has to wonder, if Africa was a cornucopia of delicious fruits and tubers as this ‘new breed’ of ancestral eaters would have us believe, why did humans abandon it for the glacial non-equatorial regions at all?

        Well the answer is there if you look at the research available. When the earth experienced its periods of glaciation, most of the available water was locked up in the ice concentrated at the polar regions. This, in turn, meant that streams and rivers ran dry, oceans receded and the land suffered drought. Succulent fruit and tubers would likely not prosper in such an environment but, more importantly, large game would also suffer from lack of food and water and their migratory range would drift away from the arid equatorial regions as they searched further afield for sustenance. It is likely humans followed along too, as these animals were their principle food supply.

        Those humans that remained in Africa managed to survive on what little food and sources of water were still available but I doubt they dined extravagantly in a lush and bountiful garden. My guess is they would have barely subsisted and constantly diced with death due to a lack of drinkable water, malnutrition, starvation and disease – much as many present-day native Africans do.

        • Africa is *still* not a lush and tropical garden, come to think of it. There’s some jungle and you find fruit there, but a lot of the continent is savanna or desert. And if you want to go into the jungle after the fruit you had better be prepared to negotiate with our great-ape cousins. :)

          • Having been to Africa several times, I would beg to differ. While it’s true that big parts of the continent are arid (Sahara, Namib, Kalahari), the main inhabited parts are quite rich, not in a monetary sense, but in a nutritional sense. Of course these parts of the continent are rather undereported in our media and the image of Africa as hell hole where people starve everywhere is exagerated (the tunnel vision induced by the media lense).
            Last time I was in Gabon, even I could survive in the forest with my limited knowledge of the edible plants there.
            The problems of Africa are more political than anything else.

          • That may be true today but I was making the point that when man migrated out of Africa – during periods of glaciation – the conditions in Africa would have been worse and more widespread than they are now (since we are currently in an inter-glacial period).

            If the argument for a high carb, plant-based ‘paleo’ diet turns on Africa having been the ‘cradle of life’ where humans first evolved and which supported an abundance of plant, as well as animal life, then you have to ask why any humans would have migrated away from there to colder climes where plant-life would have been sparse if not non-existent? And they apparently did this more than once!

            As the stable isotope evidence shows, the humans that migrated out of Africa and occupied the more northern, non-equatorial latitudes that now make up most of the European continent, were meat-eaters – in some cases to the point of out-doing the carnivores they shared the land with.

            Fossil evidence in the UK, where I live, show that humans were still largely carnivorous well into the neolithic period. If you are going to argue an archaeological basis for diet, it seems that this is what needs to be taken into account and not some rosy image of Africa as a ‘garden of Eden’ with abundant fruit and vegetables.

            Africa was a place early humans migrated away from – presumably because of a lack of food and harsher living conditions which threatened their survival and made it imperative to move away.

          • Alex you are saying that all of your ancestors first migrated to the north pole lived there for a few thousand years got adapted to eating only meat and then the migrated back to tropical periods. And now all people should eat a very low carb diet.

            Why wouldn’t most of them just settle down in tropics. You do know that asians have a different colon compared to Europeans, do you?

          • The reason why humans are such a homogeneous species is because we experienced and evolutionary/genetic bottleneck at the time of the last ice age. Some research indicates as little as a few thousand humans remained and the current human population developed from this small genetic pool.

            Since other lines of available evidence indicate most humans, during this period, ate a diet largely comprised of meat from large game animals, it is more likely that most humans alive today share the same genome as this small pocket of ancestral humans.

            As to your last point “You do know that asians have a different colon compared to Europeans, do you?”, I hope you have some solid evidence in support of that contention because, on the face of it, it sounds absurd!

        • Alex, you write like a well-educated individual. I was thus astounded to read “…as these animals were their PRINCIPLE food supply.” It’s “principal,” of course. But what you write makes sense to me.

          • Yes, I spotted that error shortly after I posted my comment but, as there is no edit function for comments, I couldn’t correct it!

            I’m pleased to read that the rest of it made sense to you! While I am writing this I may as well clarify some points raised in other responses to my comment.

            When I mentioned the migration[s] out of Africa I did not mean to infer that those migrants then moved back to Africa (though people do, even today!) to re-populate it. As many (if not more) humans remained in Africa and continued to evolve – I just question whether they would have been living on lush vegetation when much of Africa would have been starved of water during the glacial periods.

            While humans also – at some point – populated the southern hemisphere, this likely happened much later in human evolution than the ice-age migrations out of Africa – not least because the receding oceans would have provided more ‘land bridges’ and shallow, narrower stretches of water to cross into more northern areas. So it is not a case that humans migrated out of Africa to the north, became adapted to eating meat, then migrated back to Africa and other tropical regions and started eating a largely plant-based diet again! Even in tropical regions – including South Sea Islands – meat and fish provide much of the protein and, along with coconuts – fat in the diet while the availability of fruits and edible, starchy tubers allow for subsistence rations when game is in short supply. However, the period of adaptation to this increase in available starch and sugar is still significantly shorter than the period man largely lived on mostly game.

            As far as true agriculture and grain availability goes, this gets pushed further back in the human evolutionary time-line – as far back as 11,000 years ago – but only in specific regions, i.e., the middle eastern region. Globally, agriculture arrived much later on average.

    • Why are we assuming that humans ate a more varied diet before leaving Africa? The koobi fara midden shows that humans were perfectly capable of hunting deer and even hippopotamus in Africa. It’s quite possible that we were even more carnivorous before we left Africa, just as lions are even more carnivorous than wolves.

      • Exactly my point, Warren! Because edible plant food seems abundant in certain areas of Africa today – and certain populations avail themselves of it – there is an assumption that both things were true of Africa prior to Man’s first migrations out of that continent. However, as you point out, available archaeological/anthropological data, as well as stable isotope analysis of hominin fossils, seem to show that meat from large land mammals still provided the bulk of the diet. It seems to make more sense that man moved away from Africa during glacial periods by following the game herds as they sought food and water in colder, wetter climes.

  6. “Nucular – it’s pronounced nucular.” – Homer Simpson

    Maybe I’m selectively reading the paleo carbs arguments (I got tired of the whole thing pretty quickly), but it sounds to me like the drum was beat loudest for rice and white potatoes. That puzzles me, given that these are amongst the least nutrient dense “natural” carbohydrates. I can see going to bat for sweet potatoes or blueberries. But russets? White rice? What exactly are you defending here, if not the insulin high?

  7. Until I saw the same Richards’ slides, I was somewhat unconvinced by the argument that very early man ate mostly meat. I think his evidence is pretty convincing, even if we can’t be 100% sure. However, I am still unconvinced of the “dearth of tubers” argument. I do know in our own backyards, there were plenty of carbs in the form of tubers and acorns available for the hunter-gatherers who lived here before us. Most of the tuber knowledge is either lost or the plants lost due to the destruction of their habitats. A quick look at the more modern Chumash diet should convince anyone that fruits and lots of green leafy veggies aren’t necessary for survival. (At least diet-wise.)

    • Wild tuber is not very starchy, and acorns need processing because they’re very high in tannins. It’s basically the same old “seeds are plant babies and plants must defend their young chemically” concept. You could still do that today but it involves a lot of water and I’m not sure the nutritional outcome’s worth it. Useful survival knowledge maybe, and that’s about it–most of us assume we’ll be doing better than survival most of the time.

      • Acorns were more than just survival food. They were a huge percentage of the diet of more modern gatherers wherever the acorns could be found. Now I have read that the acorns with less tannin are preferred, but if you actually talk to the real gatherers themselves, they prefer the acorns with the highest tannin, and go through the long process of removing the tannin from them, because those varieties are the highest in fat and they taste better. The tubers that currently grow unattended in this area are full of carbs, but it is true that they are not starchy carbs. I don’t know how you know what tubers they ate, since researchers and descendants do not know.

  8. There’s another argument I’ve noticed in surfing the paleo/low carb sites, and it has to do with how much protein is healthy. Ron Rosedale talks about staying at around .7 grams/kg LBM to keep blood sugar lower, but you and others recommend a higher protein intake relative to lean body mass. I’m curious as to what led you and MD to recommend the higher amounts of protein consumption – right now, I’ve come to the conclusion that a higher protein consumption on a low carb diet offsets muscle mass loss, and hunger. Am I wrong on that?

    • I don’t think you’re wrong. Dr.Rosedale and I have long debated the protein issue. But, most meat, especially fatty cuts, contain way more fat than they do protein. So following a primarily meat diet doesn’t even much exceed (if it does at all) Rosedale’s limits.

        • 1. You go into ketosis overnight while you are sleeping as long as your insulin isn’t through the roof. It’s the reason your pee smells strong when you go first thing in the morning. If you want to avoid ketosis for the rest of your life, I recommend a large self-administered dose of cyanide.

          2. There’s no reason to avoid ketosis. You’d die in your sleep if it were dangerous. It is simply another means of obtaining energy for most of your body’s tissues. It’s also impossible to achieve the level of ketosis seen in ketoacidosis outside of the latter condition so don’t bother bringing up the metabolic acidosis argument.

          2a. Anyway, if you deliberately go into ketosis by eating lots of fatty meat, the meat itself is a buffering agent to any increased acidity. It contains the amino acid glutamine, which buffers acid in the kidney and turns it into ammonia for excretion.

          2b. By the way, you also turn plant protein into ammonia. But most plant proteins are not glutamine-rich, which means you must draw on your own glutamine and, failing that, calcium from your bones. Yes, I *did* just claim that vegan diets eat up bone. Ask Lierre Keith.

          3. It is possible to be in ketosis and not be throwing a lot of ketones. We talk about this in low-carb circles all the time. If you haven’t gone very far into ketosis and/or if enough of your ketones are being burned for energy they will often not be detected by ketostix.

          4. It is possible to eat more protein than fat and still be in ketosis. We have also seen this occur in low-carb circles. It’s not a sure thing and we find that raising fat intake works better, but still.

          5. Maybe if you’d stop going over to low-carb forums and ranting and calling people stupid and instead listen to them for five minutes, you’d learn a thing or two.

          P.S. The only reason I bothered with this comment is for the benefit of third parties who might be “listening in.” I know it’ll make no difference to CS. Sorry.

          • Thanks for that, Dana. I’ve eaten VLC for several years, and wondered why my ketostix never showed me to be in ketosis. One reason may be that most of my daily steaks are quite lean, but limiting my carb intake to 30-50 grams should have (I thought) done the trick. At any rate, I’m benefiting from my diet in all the right ways: great test results, optimum weight, feeling terrific, plenty of energy, no cravings for carbs and enjoyment of life. I’m grateful to Dr. Eades and posters like you and Alex Thorn for reaffirming my confidence in this approach to nourishment.

        • Thank you for the link , the article gave me a lot to think about. For example, my fasting around some unavoidable indulgences should be modified into fasting only after the event if the food would be higher in carbs. If it would be a lot of LC food, it is better to fast before because after fasting I can’t eat much like those Eskimos. The facts in the article match my experience – IF produces less glucose tolerance than VLC diet. I look slightly Asian, may be some of my ancestors are from arctic region.
          I wouldn’t mind to try that seal meat.

  9. I really enjoyed reading your series. I am new to all of this information and would like to ask a few questions.

    Fruit and vegetables have a lot of vitamins and minerals. Should we not be eating them? While I eat a lot of meat and would love to eat more; would I not be missing important nutritional components by reducing to a large degree my consumption of vegetables? There is a lot of talk about eating different colours etc.

    I am just thinking now about Hunters and Gathers. What about the gathering section?

    If we should consume a low carb diet, then what carbs can we / should we be eating?

    I know for example one supplement called Greens (I am guessing it is vegetable vitamins and minerals). Would you consider such a product potentially toxic?

    A last question I have just thought of; what is your opinion on those theories that revolve around different people requiring different diets; as in someone may be a protein type, another a vegetable type and a third a mixed type?

    Last comment; I am very happy to have stumbled on your blog. I have to say I am totally sick of people telling me that I eat too much meat and that it isn’t healthy. I really have no idea where that comes from but I guessed it was coming from those who like to practice yoga? Though I do know an x girlfriend living in China said the same thing; so in that case perhaps it is something driven by poverty?

    All the best for the end of the year and a great start for the new year.

    • Those are some good basic questions. Look around this blog, read the archives when you have some free time, and you’ll learn a hell of a lot (not just about nutrition either).

      1. Some fruits/vegetables are high in nutrients while others are pretty much worthless (iceberg lettuce, green beans). My own thought is that non starchy vegs. and low sugar fruits (berries, etc) are fine as long as your carbs are low enough (“low enough” varying for each person).

      2. If you have to hunt/gather your own food you’ll eat whatever is available. However as some have noted, you would want to get max caloric value for your efforts.

      3. I think the “protein type” vs. “vegetable type” is BS. I know of no evidence to support it. I think we all evolved to do best on high protein/fat and lower carb (though some people can indeed eat lots of carbs without problems–it doesnt mean it’s ideal for them–some people died of old age while smoking all their lives and that doesn’t mean smoking is good for you.)

      4. There are lots of reasons people object to eating meat. I think a lot of it has to do with this neo Puritanical idea that if something is fun or tastes good or makes you look good it must be bad for you.

      • @ Paul B who says: “I think we all evolved to do best on high protein/fat and lower carb […]”

        While I seem to respond well, not all people do. Suggest you review Apolipoprotein E genotype studies as they relate to nutrition and metabolism.

        A quarter of the population does not respond to low carb nutrition plans due to the expression of certain Apolipoprotein E genotypes.

        Hint: Compare the data on ApoE3 and ApoE4 alles.

  10. But why should we humans be the only one species who need fire and special tools to prepaire there foot.

    There must be some thing wrong in all the science and endless discussions.

  11. Thank you for presenting this evidence. There is a point that should be made clear: how universal is this evidence? You are showing a Gough’s cave cranium – how many other samples from different locations exist?
    Can you present a timeline of the values? We did evolve from animals that ate a large amount of plants – it would be very interesting to see the shift to meat consumption. And then we should identify when the shift back towards plant consumption occurred. That is, from the study of existing hunter-gatherer populations we know that some ate almost nothing but meat, but others consumed large amounts of plants – we should be able to see that also.

    That is also where this type of information falls a little short – the Ancestral Health Symposium was not called the Paleo Health Symposium. The reason being that we have ancestors that lived in more recent times that appeared to have great health. A non-dogmatic view of the evidence should be looking for healthy people, regardless of the time frame they lived, and try to learn from them. Similarly, just because someone lived in paleo times does not automatically mean they were healthy.

    I think there is a huge problem with telling people to eat meat today – in the U.S people eat almost exclusively muscle meat – an extraordinarily different diet than the super-carnivore humans in these studies that were eating nose to tail. For better or worse, in the modern U.S., eating plant foods similar to what healthy cultures consumed may be a much closer imitation of healthy people than eating a lot of muscle meat in a very poor imitation of the paleo diet.

    • I personally appreciate the American’s fear of organ meats – it makes organ meats super-chip , even in some fancy organic store

    • Great post, Greg. You make some excellent points, and pose some interesting questions. This is a discussion/debate that could last forever, since no absolute resolution is possible, IMO.

  12. “What do you call a failed hunter-gatherer? A vegetarian.”

    Also liked this part:

    “We have yet to find a magic phone booth that will transfer us back through time–Bill and Ted notwithstanding–to directly observe how our great-times-450-grandparents lived.”

    I think I´ve heard versions of this line before somewhere…

    Still, it´s important to define the topic of the discussion. When it comes to modern obesity and metabolic syndrome (one of the broad categories of diseases of civilization), there are even many western populations where the prevalence is (significantly) lower than in the US.

    The US obesity epidemic really only took off in the 1980-ies. It seems as if a relatively high carbohydrate intake per se does not need to lead to metabolic derangement (although that does not make it optimal, of course, but it ‘bounds’ the damage that we can expect from merely eating a large share of carbs).

    I personally suspect some kind of threshold effect with high carbohydrate intake, fructose intake and trans fat intake combined causing an explosion in fatty liver, pathological insulin resistance, and hence, essentially a broken metabolism. Mitochondrial dysfunction is also an interesting aspect of the whole thing (Peter at Hyperlipid has been writing a lot of interesting stuff in that vein).

  13. Do you really think there are a great number of people are trying to emulate a paleo era diet? My impression is those types are a tiny minority and most are using paleo as a framework.

    Starchy carbs are added to avoid complications (like increased cortisol), they reduce cost, and they taste good, so long term compliance is much easier.

    • Starchy carbs are horrible for those of us who are insulin resistant. I avoid them at all costs and really have no problems staying on a low carb diet. If I want “dessert”, I have a small amount of berries with full fat Greek yoghurt.

      However, I do not follow a “paleo” diet, just a low carb diet.

    • I understand the reasons not to eat zero-starch, however , in my case (I am not the only one) ,the lower amount of starches I consume, the easier for me to stay on the diet, the less I am interested in eating, so compliance is higher. I didn’t notice the difference in cost, because more starch equals more food.

  14. Great Post, Dr. Eades. I ran across the concept of carbon and nitrogen tagging in Micheal Pollan’s book, The Omnivore’s Dilemma. I am glad you brought that up, as all the ad hoc speculation about evolution often sounds nice, but it supposes a lot that if you look at it clearly, you may think twice. It is easy to then to fall into the same mistakes that are a hallmark of Keyes work, the classic correlation does not imply causation. The question I have for you is: I was raised on a traditional Mediterranean diet, and frankly, I hate the stigma associated with it, as my mother knew sweets, bread, and potatoes made you fat. The mediterranean diet is a lot of things, and I find it a shame that it is so strongly associated with Keyes. Italian are some of the thinnest people in the world. Spanish food is not super high carb (tapas and wine is a great meal if you don’t gorge on bread), and where I am from (Montenegro) has a lot of 100 year olds. They don’t eat bread and pasta. When I was there breakfast was fish and eggs and cheese Pita (not american style with tons of fillo dough!) some prosciutto cheese and wine for lunch and dinner could be seafood again with some wine and perhaps fresh yogurt/kefir for a midday snack. I guess what I am saying is that I would like to see not only the death of the lipid hypothesis but the stigma associated with a Keyes-style mediterranean diet versus a traditional diet from the Mediterranean (which I think it much much different), and I think are much healthier, low carb, and such. What do you think? I know that you might feel that agriculture was the worst mistake in humankind, but there were obviously some cavemen way back when who said the opposite, right? I guess, my point is, do we need to go back 10,000 years to get it right, or can we just appreciate out grandmother’s cooking? I had a lot of soup with fat bubbles in it growing up, and now it’s called paleo bone broth. I just call it my Baba’s soup…

  15. Forgot the quote: “According to their data the average daily food partition is about 280 gm. of protein, 135 gm. of fat, and 54 gm. of carbohydrate of which the bulk is derived from the glycogen of the meat eaten.”

    • According to data generated in the famous Stefansson all meat diet study in Bellevue, dietary composition as a function of energy was over 80 percent fat, 15 percent protein and a smattering of carb.

      • Hi Dr. Mike,

        As your resident “zero-carber” (99.9% of the time!) for the last 3.5 years, I can attest to the notion that the fattiest cuts of meat supply me with the most energy throughout the day, and I never worry about my protein consumption, because I know it basically will self regulate itself through my diet.

        I often ask the butcher for scap pieces of fat (for free!) and supplement that with whatever cuts of meat (which is usually trimmed) that I am eating at that time. The higher the percentage of fat for my meal(s), the longer I am sustained from feeling “hungry” (which for those of us eating esentially “no carbs”, we know that it is a very gradual hunger that builds…..because of no blood glucose spikes).

        I often go a full day without eating….but some days, I’ll eat 2 or 3 meals. Once adapted, I have no doubt (antecdotally speaking of course) that a nearly carnivorous diet is an effective way to achieving phenomenal health….if not the best way!!

        Good health to all!

      • The folks who used to live in my backyard ate mostly fish and shellfish, small game, and tons of acorns. There was little fruit and virtually no green vegetables. The only sweet thing was yucca flower. A quick look at an non-irrigated landscape will tell you why. Even in years with rain, there is little that looks edible except for acorns and the occasional rabbit. People who say our ancestors feasted mostly on fruit and veggies do not understand the confluence of resources that must happen in order for a constant supply of fruit to appear.

  16. Early humans did not necessarily eat like modern carnivores, but I had an interesting experience last winter. I have a few sheep, and when one dies in the winter, I compost it in the manure pile.

    Last winter, I hadn’t dug deep enough into the pile, and something started eating a dead sheep. I suspect it was a fox, but I don’t know for sure. I kept re-covering the sheep and it kept re-digging, and so I finally gave up. The reason to bury animals is to avoid attracting carnivores, and it was already too late for that.

    What was interesting was what it ate. It started with the eyes (high in omega 3) and lips. Then it went for the liver and other entrails. It left the rumen (containing mostly chewed grass and fermenting bacteria). Only at the end did it start eating the leg of lamb and other muscle meat.

    I’m sure people have studied this more formally, but it was interesting to watch.

    Some people claim that arctic people get vitamin C from eating plant material in stomachs of caribou, but others claim that, like this carnivore, they throw that away. You can get vitamin C from raw meat. One group in Siberia eats frozen raw whitefish as a snack, and whale blubber is apparently also high in vitamin C.

    • Gretchen, I can relate to your observations as well from my experience growing up on a cattle ranch in eastern Oregon. As a young man I would routinely go out and check on the cattle after a big winter storm and invariably find a dead cow on the range occasionally. By the the time I came across the downed animal either frozen solid or barely alive with blinking eyelids, the local carnivorous animals had usually already started in on the eyes, tongue, lips and skull, followed by the anus and the entrails all the way up through the thoracic cavity clean to the ribs before starting on the tougher muscle meat over a period of days.

      Also, if you have the opportunity read the book Undaunted Courage by Stephen Ambrose, an autobiography about Meriwether Lewis and the Corps of Discovery and their journey a little over two hundred years ago (during the Jefferson presidency) from St. Louis to the Oregon Coast. I remember the mouth watering descriptions of the big game they hunted, with herds so large they spanned the mid western plains as far as the eye could see. Most interesting was his journal describing the “savages” they encountered along the way and their eating habits. Upon the soldiers shooting and gutting a large animal the Indians would fall upon the viscera thrown to the ground and devour it raw, leaving the muscle meat to the “civilized” soldiers.

      Interestingly, by the end of the first winter of the journey and nearly starving to death in the Sawtooth mountains of Idaho, the soldiers resorted to eating their own horses and dogs, with the dogs being described as their favorite meat out of all the meat they ate on the journey. All though that may be partially due to the amount of hunger they were feeling at the time.

  17. I’m not drifting from my low carb Paleo diet Dr Eades ! Been on it since I read your book five years ago and have never looked back. I probably get only about 30 to 50g carbs per day which comes from leafy green veggies and nuts like almonds, the rest is proteins and fats from meat, fish and eggs and good fats like coconut oil. I love it :-)Don’t find it difficult at all and I don’t miss carbs either :-)

  18. I am confused by the graphs. On the first one, Arctic Fox is above 8.8. On the second one, Arctic Fox is at 5 and humans are between 5.5 and 7. Can you explain what the difference is in the data? If Neanderthals were at a 10 and considered top predators, what does that mean for humans at between 5.5 and 7. On the first graph, Bison are at a 5.5.

    • @Lisa
      The numbers are the differential in the N values. That is, the figures only matter relative to the surrounding flora from where the samples were taken, they aren’t absolute numbers. So, if in the one example the figures are higher (or lower, as the case may be) it means that in the particular region where the data is collected, the differences are greater (or lower) than was found in another region. However, the relative differences in the N values between various species in one region may be similar to the relationships in another area, but the actual numbers differ because of variations in local flora. I hope this makes sense.

    • Hi Lisa…Juan Martinez is correct. I would have responded to your question – which I intended to address in the post but forgot – yesterday or earlier today but I’ve been traveling and have had only limited opportunity to check and approve comments and no real time to deal with specific questions.

  19. PS – wanted to add that it’s so nice you’ve written a blog again – I’ve been looking in vain for one recently. Happy Christmas !

  20. I have spent 2 1/2 years studying my diet, often recording for months at a time on Fitday. I have eaten carbs for periods of time at every level below “Lots.” My predominant exercise is just biking pretty hard.

    What I found out is that when my carbs are down in the <100 gm/day, I do not have the glycogen stores to work hard. And I just feel a tad spacy. Never got over the alleged carb flu, no matter if weeks went by.

    Nowadays I aim for 150 grams or so (And, oh, I'm a large man.) I feel much better, can ride harder, and I enjoy the addtions of starch to my diet. The team over at lends a lot of credence to this type of macronutrient intake.

    We didn't develop amylase for nothing……..

  21. Dr Mike,
    Your readers will be able to see Mike Richards demonstrate the whole analysis process, explain the results, answer the ongoing ‘paleo plants’ debate (in Europe) and the “human vegetarians?” question himself in my investigative documentary beginning in about 30 days (late January).

    They’ll also see you several times, including your medical remarks on vegetarianism and description of the differences between herbivores and carnivores digestive systems.

  22. Just a note to say I agree with you wholeheartedly about the science behind the low carb nutritional approach. I do my research and read as much as I can to make sure I’m not just accepting something on faith – but every once in a while, I run across a highly scholarly (to me) refutation of low carb – or more accurately a support of the lipid theory. You being much more educated than I, can you tell if this review of a book on Amazon has any arguments that are sound?

    • @pmfith
      I looked at that comment and yes, it is rather thorough and very science-y, indeed. However, it also seems as though it is Ansel Keyes himself speaking from the grave. I mean, really, mentioning post WWII Crete? The writer also conveniently ignores a much more recent meta analysis than the ones he cites, which completely contradicts them. In Mar 2010, a major meta analysis by Krauss, et al., in the American Journal of Clinical Nutrition, found NO association between dietary saturated fat intake and CVD or CHD. The analysis looked at studies that covered hundreds of thousands of individuals who were followed for anywhere from 7 to 23 years.( Dr. Ravnskov isn’t the only one who is skeptical about cholesterol being the villain. This reviewer is clearly a shill for the vegan brigades. lol

  23. Hi Mike –

    I wonder – have scientists like Dr. Richards tested the bones of living vegan humans to see if their bones resemble that of herbivorous animals? As I see it, that would be telling indeed.

    Also, how would it be that an Arctic fox would have such a lower reading? I mean, how much more carnivorous can you get than a fox or wolf? A bear I could understand but it seems to me that if the fox or wolf “scored” lower than a human it suggests, does it not, that human bone reacts differently than animal bone to protein/fat ingestion?

    Just wonderin’…

    • Fred, a super carnivore is a carnivore that eats other carnivores. This means a wolf or a fox was not that high because it eats only herbivores. A wolf eating a lot of foxes would climb in the ratio. This means that early man not only hunted herbivores but also other carnivores (bears or more likely hedgehogs).

    • Because a fox could be 100% carnivorous yet only eat herbivores, yet a 100% carnivorous human could eat herbivores and carnivores, skewing δ15N up.

      He addresses this:

      Any animal, including man, that dines on herbivores will have collagen sporting a δ15N that is about 7 percent greater than that found in the herbivores that are the meal, a fact confirmed by stable isotope analysis of known carnivores. A super carnivore (for lack of a better name) that dines on other carnivores and herbivores would have an even greater δ15N level.

    • I am definitely with you, every single word of yours, both of the issues.
      Dr. Richards must have verified his methods by testing living vegans and low carbers. If not, there is something to doubt here.
      Also, being more carnivore than a wolf? Something is not clicking here.
      I really would like to have answers to these two points, or I’ll stay in doubt about my diet forever :)

  24. I honestly believe, based on Stephanie Seneff’s work, that the only reason tropical-region Homo sapiens gets away with eating all that tropical fruit is threefold: one, they also get plenty of fat, which blunts the sugar response; two, they probably get plenty of choline, since I have yet to hear of a non-scripture-based traditional group that doesn’t eat liver; and three, they get lots of sunshine.

    Seneff’s got a really interesting argument that cholesterol sulfate in the body is important to metabolic health. Most people who live in the tropics live on sulfur-rich soil and therefore have a plentiful stash of cholesterol sulfate in their bodies. (Maybe that’s argument four.) And when they go out into the sun, which they cannot help doing if they want their cultures to continue to function, some of that cholesterol sulfate gets turned into vitamin D sulfate, which Seneff argues is much more effective for metabolic health than regular vitamin D.

    People living farther away from the equator, for whatever reason (I have no idea why there are more volcanoes near the equator, might just be an accident of plate tectonics), are less likely to live near volcanoes and are less likely to have a lot of sunlight (especially in winter) and the farther they are from the equator, the more they must rely on food for vitamin D. (I was interested to learn that salmon is a prominent part of the mythology for several Arctic-region peoples, not just New World Indians. Salmon is one of *the* best sources of vitamin D in the human diet.)

    Those people do not have the wiggle room to go around eating bags of sugar all day long. They can compensate somewhat with fat and choline but the compensation will be incomplete and, anyway, they don’t get fruit year-round the way tropical people apparently do, so the point is moot.

    If you have to make sure a whole bunch of other factors are in play before you can eat carbs, maybe it’s just simpler to not eat the carbs.

  25. I’m around people who exercise a lot and claim they need the carbs to do the work – that’s where I can’t navigate the low-carb argument well. Please help me out here. When the “global we” discusses a low-carb diet, is it safe to say that it’s a diet for a certain activity level? An activity level that allows for a run after prey, followed by preparing the carcass for eating, but not something one does *every day*?

    When humans increase their activity level to be able to run or bike long distances or build large muscles, etc., do they then need the extra calories or glucose provided by carbs? Or could they do this on a low-carb diet? I’m surmising that those with a high activity level, like Paul, don’t have a problem with weight gain after eating 150g carbs/day, so they aren’t motivated to stick through a low-carb diet enough that they get past the “low-carb flu”…why put oneself through that…

    People who eat lots of carbs then need to eat lots of carbs to feel satiated. I exercise better on a somewhat empty stomach. I go to a boot camp class that way and get through it better than most. The instructor is always asking for hands-up of who ate something at least an hour before class. I raise my hand because I had heavy cream in my coffee (chuckle).

    A friend said that animals don’t have a “good breakfast” before expending tons of energy going after prey. They eat afterward when their bodies know how much food is needed to replace that which was spent. Once I started reversing “stocking up” with “replenishing”, eating went from crazy to sane.

    • If you exercise so much that you deplete glycogen stores to the point where gluconeogensis can’t keep up, then yes you’ll need to eat a yam or two.

      But why exercise so much? It’s not a great idea to hasten the aging process by having your cortisol and free radical levels constantly elevated.

      • heh heh, well, yes, there is that question, too. The ultimate in fitness when I grew up was to run and run and run (and run). And in mainstream media, taking any athletic endeavor to extremes is extolled and venerated. However, I’ve liked the question “fit for what?” to defines fitness. I like to challenge myself, but I’m not hard-core. I’m finding my personal physical “trifecta” in lifting weights for strength, yoga for flexibility, and karate for movement. To be able to do each one, I can’t overdo the others. Balance is a bigger challenge than overdoing one thing!

        Do you think people overestimate the point at which they (or others) need glycogen? The word is out there with a vengeance: replenish your glycogen stores! after a person does a once-a-week exercise class. Most people I know at the gym talk carbs *still*, but I’ve not understood how a higher level of activity affects carb needs. From what you say, it seems like it is probably overstated.


      • This argument appears often in the Paleo/low-carb world, but is there study data to back it up? Maybe I need to review some of the Paleo books.

        There is study data showing that trained response to exercise is very different than untrained. Trained response shows much less depletion of anti-oxidants and faster recovery.

    • Kristen, I once read a memoir by a Canadian preacher who traveled into the “outback” accompanied by a native guide. The way they travel is much more strenuous than recreational running. They run behind dog sleds, through deep snow, often for hours at a time and can keep this up for days.

      The guide ate mostly caribou. But once, they discovered the village where they’d planned to restock their meat stores was abandoned, so they were forced to survive on their emergency food, which was all carbs.

      The native complained that on the carb diet he didn’t have enough energy to run all day.

      This is annecdotal, sample size of one. And it doesn’t prove that meat provides more energy than carbs. But it does suggest that we are most efficient on the diet we’re accustomed to. And this one guy, at least, had plenty of energy without carbs.

      However, I know a power lifter who says she follows a LC diet except when she’s competing, and then she says she eats more carbs because she said she’s found she can lift more weight when she does.

      • Interesting, Gretchen, thanks. Makes me wonder about those sherpas who carry all the stuff for the Westerners who climb Mt. Everest. I wonder what they eat? (Not much of an accomplishment if you have guys who can carry your stuff *and* do it along with you.)

        I know a woman who is training for her first bodybuilding competition (she’s 56). It’s interesting to find out the ins and outs of this process. To be honest, though, I think it’s the “train wreck” to the body aspect of it that makes me lookie-loo. I have no info to back this up, but it seems to me that it can’t be good to yo-yo your body around like that diet-wise, especially at the end when, apparently, the day before you cannot drink any water.

        Most bodybuilders I’ve seen at the gym seem to bounce back up a bit in weight/fat after the competitions. I’ve always thought that it seems like it would be easier to keep lean via a very-low-carb diet and not go crazy for three months on their diet plan.

    • In order to exercise successfully in a fasted state or ketogenic state, people have to be adopted to it. I remember going through different stages – at first it had a concrete legs and could even develop a headache after 45 min of very intense physical activity. After I got adapted, I noticed unusual increase of endurance, because my body got used to maintain a steady level of glucose in blood for hours without doing carbo-loading first . There is no “bonking” for me any longer. There is a blog of a trainer and bicyclist from Australia who is eating in Paleo-style . Somewhere there are several article how to train on a high-fat diet.

  26. This was one mammoth of an article for you to write. Wow is all I can say.

    The thing that I don’t get is does it matter what our ancestors ate? To some degree it does. But what if they too were eating the wrong thing like we are today? In 10,000 years people could look back and say the optimal diet for them is bread and twinkies because that’s what we’re eating now.

    The real question is what we were designed to eat.

    I’ve bookmarked this sucker. Thanks for putting so much time into it! :)

  27. Firstly, we are forgetting that Paleo and Neo were not the only game in town. There are intermediate lifestyles; animal herding nomads, or semi-sedentary island dwellers who must practice HG while tending some crops, like Maori or other polynesians. So there is a spectrum, which probably predates classic neolithic farming by aeons. Perhaps grain eatring evolved as an emergency use of an animal feed, when herds were decimated and only the feed was left.

    Secondly, the fruit-eating paleo argument fails in two areas; modern day HGs often ignore fruits unless starving, and on forays into the forest, early savannah hominids would have been competing with far better adapted fruitarians; gorillas and chimps – protecting their territory with fang and claw.
    By the time we developed the tools to make effective raids, those same tools would have ensured a better food supply on the savannah.
    If man evolved to eat veges, we would all be born with stopped backs and low posture, not running with hands free.

  28. Meat can be digested without fire much more easily than, say, taro or cassava. FWIW, I find roots like beetroot, parsnip, swede (rutabaga), turnip, carrot, roasted with the meat, to be unobjectionable carb additions to a paleo diet, with little or no impact on insulin, unlike potato, sweet potato, or rice.
    Anyone interested in a sane perspective on the Paleo carb argument should check out Kurt Harris’ Archevore blog.
    An “all-meat diet” is the standard-of-care for insulin resistance, but I think once you have IR beat there may be safe carbs; mainly roots.
    Don’t forget the true paleo carb – honey. Even today there are HGs living well on meat and honey, as the Abyssinians did in Bruce’s day, and ignoring other carb foods. Mabe counter-intuitive, but we have to account for it.

  29. Dr. Eades,

    Thank you so much for this wonderful post. I have been living low carb since I first read your book in the 1990s. I absolutely believe this is the way to optimum health and how we were designed to live. The amount of sugar and processed foods consumed by everyone around me is appalling – and the rate of obesity I see is even worse. I can only imagine how you must feel! When I first started eating this way of course my doctors didn’t hesitate to tell me how crazy I was. But just recently I was having an issue with maintaining my low blood pressure which of course coincided with my increasing age (52), perimenopause, and my husband’s recent cancer diagnosis. (Which is important because under that stress and daily treatments, I couldn’t really focus on eating the right foods every day.) So when I told my doctor I needed to manage it by going back to low carb eating – to my shock she completely agreed. So we’re making progress!

    I do have a question that while not critical to the discussion, I have always wondered about. When we talk of Paleo ancestors and their diets, we always talk in terms of what we are used to eating in this country and in this generation. Wouldn’t our ancestors have consumed insects as well? Now don’t get me wrong – I am not advocating for an effort to gather grubworms!!! But seriously, would this not have been a source of protein for them? Or maybe there is little protein in an insect – I am not sure. What does the science tell us about this?

    Thank you again for all of your work and for standing up against the “conventional” wisdom!

    • Regarding insects, you’re absolutely right. Many of them have a large percentage of high-quality protein, up to 90+ percent in some cases. Insects are the ‘hidden’ food that is often ignored or overlooked in mammalian diets. I remember reading of a survey of stomach contents of coyotes once. Coyotes eat rabbits and mice, right? But the survey showed (for the sample used in the study) that on average insects comprised 70 percent of the stomach contents by weight.

  30. It’s December and the damned elk are trampling everything! How am I going to find fresh fruit in order to survive? I sure hope there’s some tasty tubers out there in the frozen ground…

  31. I thought that what separated paleolithic from neolithic man was agriculture – the mass growing and processing of cereals (in addition to animal husbandry). so wouldn’t this mean that only those carbs that are derived from cereals and pulses, are the ones to avoid? not starchy tubers, etc.? In addition to evidence about the difference in pre- and post- agrarian man’s health, wheat specifically, is known to just be indigestible, and I believe, more than anything else, the culprit to so many of our world’s health problems.

    • While western culture thinks of wheat as the basis of agriculture, starchy tubers are in fact just as much agricultural foods. They just happen to have been developed by tropical cultures rather than Europeans. Indeed, there are some signs that the first agriculturalists were in Papua New Guinea, and their crop was taro root.

      • Actually, wheat was first cultivated in the Fertile Crescent (not Europe). And because of the major amount of processing required, its what really is defined by the agricultural age. I do agree that small tribes in the tropics including Latin America, Papua New Guinea, and many other parts of the world had small gardens/kampongs/etc, where they planted important food crops. But starchy tubers do not require the same amount of effort in processing that grains do, which have to be grown on a very large scale, threshed, and processed by a team of many people (eventually replaced by machines). I believe that’s where the distinction lies.

  32. Moving North: Archaeobotanical Evidencefor Plant Diet in Middle and UpperPaleolithic Europe Martin Jones Abstract
    This paper reviews the evidence for Middle and Upper Paleolithic plant foods in Europe and neighboringregions. Up until now, most research into the prehistory of plant foods has been conducted on Neolithic and post-Neolithiccommunities. In recent decades, that has been extended to explore preludes to agriculture and to connect contemporary ethnobotany with the recent archaeological record. The review conducted here shifts focus to the problems of Paleolithic human ecology itself and the challenge of acquiring sufficient plant foods in the novel environments that the first generations of humans crossed and colonized

  33. Ok, our ancestors ate a lot of meat, but how long did they live?

    Our biological processes are designed to help us reproduce not live a long time. If we do live a long time some of these processes now cause us trouble.

    The fact that children are developing diabetes and heart disease support the idea that we have too much sugar in our diet.

    But I’m still questioning if grains and dairy maybe helped us to live longer or provided some other benefit to the species…like just plain having more food to support people so they can have babies.

    Is there enough meat on the planet to feed 7+ billion people?

    • The 7 billion people are a result of (grain)agriculture. HG and nomadic herders don’t tend to grow exponentially. So your objection would be better formulated as, how do we get that genie (grain agriculture) back in the bottle, without being evil eugenists (like the Club of Rome and other 1st world supremacists).

      • I don’t think I’m objecting to anything, but thanks for the information that grain agriculture results in population growth. Judgement on whether that’s good or bad is not something that I’m offering.

        I guess that @Al highlights the issue, individual success vs group/human success. Are grains successful for humans as supported by population growth or bad for humans as supported by illnesses that come from them?

        If the grain is fermented or soaked maybe grain is not so bad, maybe it’s just the processing of grains or the genetic modifications to grains that’s the issue.

        Again I don’t know guys, I’m asking questions :)

        • ALL grains are bad for diabetics, to varying degrees. Whole grains are simply a little less bad. And of course processed foods are uniformly bad for everyone. The diabetes/obesity epidemic in the US began at roughly the same time processed foods became cheap and ubiquitous.

      • Why do you declare that eugenics is evil? Mother Nature is the original and ongoing source of eugenic selection — and it’s actually a good, if emotionally painful, thing for any / every species. (Mother Nature doesn’t give a hoot about emotional pain!)

        Humanity’s insistence on “save every human,” regardless of the effect on the planet, on successful living of other humans (and other animals), is actually a MISTAKE — because it does more damage, than allowing Nature to take its (her) course. Saving a generation of starving children, so they can just barely grow up and create another generation of starving children, secula seculorum, is surely LESS optimal than allowing the natural process of death of maintain a sustainable population number on the globe?

        • Natural selection =/= Eugenics.

          eu·gen·ics (y-jnks)
          n. (used with a sing. verb)
          The study of hereditary improvement of the human race by controlled selective breeding.

          Eugenics is evil because one class of people gets to decide how and if the rest get to reproduce, based on the criteria (and biases) of that class.

          • How you managed to leap from (*your own* posting of a definition) “study of improvement by controlled breeding” to ‘evil class of people’ is astonishing! If a person whose parent is mentally ill decides not to have children to prevent those genes from moving forward — that IS eugenics! What’s evil about that?! If a family with Huntington’s chorea decides NOT to have children — where is this evil class of people you’re seeing? Or would you deny that’s eugenics?!

            I WISH humanity would start using some eugenics to prevent the continuing decline of the human species!

    • The population of the planet has more than doubled in the past 50 years. If that happens again, will there even be enough grains to feed 14 billion people after the next 50 years or even to feed the 9 billion actually projected for 2050? I’m not sure that enabling the expansion of the population at such rates would be called a benefit.

  34. @Justin – The way I see it, our ancestors evolved to eat the foods available to them, and this was over a long period of time. If a certain food source didn’t work for the bod, those who ate that food wouldn’t survive. The problem is that human technological progress went faster than human evolution, and humans started introducing farming and then ways of keeping foods fresh to be able to transport them faster than our bodies were able to adapt to them. Plus, we also developed ways of treating illnesses so that people who might have died from eating sub-optimally, were kept alive and able to have offspring – the consequences of eating the wrong foods – from an evolutionary standpoint – was disrupted, and more and more “wrong foods” got into our diets. There wasn’t the proper separation of “wheat from the chaff” LOL.

    Actually, when humans started eating grains, I believe that most cultures developed ways of making them better for the body by fermenting them.

    So when people of the future look back at Twinkie-eaters, they will be looking at a very different scenario, evolutionarily-and-technologically-speaking, than our looking back at the earliest humans. It’s not simply looking at what people ate but rather looking at how the human body evolved – how long that took, impact of introducing new foods too fast, etc. At least that’s how I understand it.

  35. @Gina, I’m not taking responsibility for feeding 7+ billion people, I’ll tell you that right now. Nor will I fudge the science
    in the hope of somehow adding to their diet.
    Actually you and I can alleviate world hunger a little – by not buying up staples like quinoa when they become fashionable, and thereby forcing up the price so that the original eaters are then forced to eat wheat or corn (it happens).

  36. @George, I don’t think anyone is asking you to take responsibility for anything/anyone, nor is anyone asking you to fudge science. Not sure where you are coming from.

    The questions I raise I think are reasonable:

    1) Are there any advantage to eating grains and dairy? ie do they support a larger population (that reproduces). Is that considered success?

    2) The assumption that neolithic man “succeeded’ on a meat-based diet, begs the defintion of success. If it is procreation to maintain population, ok. If success is to grow the population, ok, will paleo diet do that?

    I don’t have an answer, just hoping someone may have thought about this or some variation thereof and we can have a good discussion.

    Let’s not get combative, ok?

    • It looks like the agriculture is very successful in destroying humans habitat than hunting, but can provide for larger population until the habitat gets destroyed. However, ancient people turned to agriculture partially because they hunted down animals they eat. So there are two possible scenarios to compare – 1.- Hunters couldn’t multiply their numbers on the limited supply of animals, they were forced to actively fight with other tribes for the territory, it kept their numbers down; 2 – People discovered habitat-destroying and health-destroying and civilization-creating agriculture, so they multiplied more successfully, and the fruits of civilization let them bring the battle for resources on a new level. There is no perfect scenario, we can’t change history, but we can optimize our life-style and eating in order to live a healthier life. It is irrelevant for my personal health how to feed humanity. My way of eating a grass-fed meat and not a food in boxes, contributes to more environmentally-friendly agriculture and generates less garbage, I also need much less than average person in my age group (51) in the terms of medical care and services. I can’t contribute more . We can’t save humanity, but we can take care of ourselves.

      • Galina,

        It may be a luxury that some have: to eat grass-fed meat and not contribute to health care expenses.

        Another aspect is did the agriculture-based societies contribute more to society (rather than an individual)? Did they create complexity, science, music, specialization?

        If we were all hunter-gatherers maybe we’d spend all our time hunting and gathering, and nothing else. We’d be happy, maybe even live for a long time in small supporing communities and presumably not reproduce much. It could be ideal!

        But what impact would that have at society at large? I’m not talking about an impact with specific greivances and specific responses. I’m talking about a sociological consequence. Would there be less innovation? More innovation? Would there be more pronounced haves and have-nots? Would grass-fed eaters become the 1%?

        Does it matter?

        • It is a little Beyond the Point Of No Return to discuss the value of agricultural society, because we live in one and there is no way to reverse it because it was before us, we are the product of it, like we can’t choose parents. There are a lot of reports that people in haunter-gatherer societies had plenty of free time, agriculturalists tend to be very busy, with the exception of elite. Probably, agriculturist elite is more happy than an average hunter, with enough access to surplus of resources to hire a musician or a painter.
          The question is not about which society to choose, but how to find the perfect compromise in our modern life. We can’t micromanage how humanity lives, but we can contribute to the changes we approve, like buying the product that was produced in more environmentally friendly way. It is an illusion that eating grass-fed meat is too expensive. Just count how much average family, even in a low-income bracket, spends on unnecessary foods like cereals, bread, cookies, sweetened beverages, various snacks, ice-cream. Yes, high-carb food is mostly chip (not true for stupid cereals), but people are eating a lot of it because they are hungry all the time. My son had to eat in cafeteria during his first year in college, he spend of food almost 2 times more than now eating one lb of grass-fed meat a day, 4 eggs, some cheese, veggies, potatoes, pastured butter. His eczema went dormant. I buy a lot of organ meats, eat 2 times a day without snacking because my diet is very satiating. It is not a luxury, but required a lot of adjustments at the beginning.

          • You’re right the question IS NOT what society to choose.

            I too eat pastured grass-fed beef and poultry, raw whole milk and cheese, bone broths, salt, pastured yellow butter, and organ meats.

            My son eats these same foods and has lost 13lbs because he is satieted sufficiently but does not have enough calories. I have just switched to adding more carbs (balanced by fats) to change this trajectory.

            We all do have individual aspects of our lives that work for us, or not. Speaking for yourself is one thing, extending a formula to the greater population is another. (I don’t think you are doing that Galina!)

        • @gina:

          It seems to me that one could make the case that the advent of agriculture not only adversely affected human health, but it also allowed for the imposition of slavery and other forms of feudal servitude, which created a system of have and have-nots that could create opportunities for a privileged few to specialize enough to move technology forward and increase population densities. While it may very well be true that without this period of slavery no society would ever have had the opportunity necessary to drive humanity forward, I would suggest that it is quite possible for us to preserve the benefits we’ve acquired throughout history, while attenuating the harms. We’ve already done away with indentured servitude and slavery (for the most part) – I firmly believe that we can take the next step and do away with the deleterious health effects of carbohydrate consumption as well.

          Makes you wonder about what combinations of technologies will be necessary to provide animal protein and fat sufficient for say, 50 billion people. I don’t know enough about animal husbandry to know what that will take, but it’d be wonderful if that could happen in my lifetime!

    • An agricultural diet allows women to put on fat faster and become fertile more quickly after having a baby – often with a birth interval of a year or less, as opposed to 3-4 years for women on a hunter gatherer diet. It also means the majority of those babies died to disease before adulthood, but the net was still positive from a population growth standpoint, and resulted in a steady growth of the human population throughout the agricultural period.

      So yes, if your goal is to have as many babies as possible, and you don’t care about the ones that die as long as you have more that live, agriculture is definitely “successful”.

  37. “Early man migrated out of Africa where there was plenty of sunshine and a wider variation of nutrition. Why? But after the migration, he lived in northern latitudes for thousands of years (without going back)”

    While early man did migrate out of Africa, he did not evacuate Africa, he’s still there & evolving. And of those that left Africa, many, possibly the first and most prolific, followed the coast from Arabia to Iran, Pakistan, India (where I live), Bangladesh, SE Asia etc. There’s lots of fruit around here, things grow 12 months in the year. Perhaps it was drier during ice ages, but then, a lot of land currently underwater would have been habitable. Check out the water depth around Malaysia & Indonesia. It’s pretty shallow.

    Further, race is recognized as an un-scientific concept because our genes, across continents, are so heterogenous. While the post’s isotope evidence is great, the interpretations I’m seeing tend to be Euro-centric. We need more evidence from a wider time span and over broader geographical areas interpreted more cosmopolitanly.

  38. In “Cro-Magnon’, Bruce Fagan stresses the role of the ice ages in making us human – we developed the template for most of our tools and weapons. He points out that ice-age cro-magnon would have been lucky to get one cup of plant food a YEAR! And yet as Spencer Wells claims in his book ‘Pandora’s Seed” our ancient grand parents were healthier than even modern humans. Recently I visited the Museum of Prehistory in Les Eyzies, France and was fascinated by the many displays that illustrated the climate Cro-magnon ‘enjoyed’ for tens of thousands of years — the temperature ranged from a balmy 4′ C to -20 ‘ C – not too many fruits, veggies or tubers could handle that range I imagine– but thankfully the environment meted out enough indigestible (to us) plant food to fatten up the herbivores — our preferred food. And though Africa didn’t freeze over, it was still affected by the ice age — it became much drier and less hospitable. It was not a garden of eden of fruit during the ice ages nor is it now. Even today in Africa there are distinct fruiting/flowering (non-fruiting) seasons. An enterprising scientist laid plastic under the forest canopy to catch the droppings of orangutans — and lo and behold, she found that during the non-fruiting season our cousins were burning fat and excreting ketones. (Changes in Orangutan Caloric Intake, Energy Balance, and Ketones in Response to Fluctuating Fruit Availability byCheryl D. Knott)Same goes for the gorilla — gorges on fruit when available, but during their version of ‘winter’ they eat a high protein diet a la Atkins.

  39. Hi, Dr. Eades,

    We sure are meat eaters. New anthropolgical evidence demonstrates this.

    Recently gained scientific knowledge confirms that the earliest human ancestors from 4.2 million years back SKIPPED FRUIT ( or ate very, very little) , and went straight for nuts, root vegetables , INSECTS and MEAT.

    The fruitarians have been debunked by mainstream genuine anthropology science.

    Here is the article:

    or Google “Earliest Human Ancestors Skipped Fruit Went For Nuts”

    Take care,

  40. Judging from my own experience with a vegetable garden over the years, I’m not the least bit surprised (and have always suspected) that early man would not have been able to acquire very much of the stuff. The cabbage worms infest everything, racoons and birds eat the grapes, (not to mention leaving their noxious and toxic poop all over the deck so we couldn’t even sit NEAR the grapes) groundhogs eat the pumpkins, fungus and rot eats the tomatoes, Cedar Waxwings eat the berries, bean beetles eat the beans, coddling moths eat the miserable pears, the squirrels get all the walnuts, and so it goes.
    I can get onions, however, unless the nematodes get them first.

  41. Hi Mike!

    Another great post which I am going to refer to endlessly like others you have written. To add to this I was talking with an animal nutritionist with UC Davis a few months ago and she mentioned that the human digestive tract is much more similar to that of canines (dogs) then porcine (pigs) ….so on the spectrum we are well-adapted to survive and “thrive” on just about anything but, when we can, we go for the fat and meat. Our ability to make tools, cook and strategize our hunt are probably the reasons we can outcompete foxes for carnivorous treats even though their digestive tract is more carnivorous than our own and that we definitely need more fat to help with the protein digestion and uptake. Thus we are probably “carnivorous omnivores” and as you so aptly point out thrive on a diet rich in animal fat and protein (as a percentage of total caloric intake). My term for most of the Paleo out there is “PC Paleo” b/c most of the “gurus” in the blogosphere and writing books etc.are loathe to use the “F” word for fat and when they do its the “good” fats (read poly unsaturated, and mono unsaturated) and that fats, including saturates, need to consitute the vast majority of caloric intake to keep the human body in its natural state of in or fluttering around nutritional ketosis (excetion: T1 diabetics) and gluconeogenisis. Keep up te great work!

  42. Hey Mike,

    I was really hoping that you would loosen up your position on starch in the face of new evidence. The last paragraph of this post does offer some wiggle room, but it is clear that you are still firmly in the low carb camp. That’s understandable given your clinical experience, but at some point you are probably going to need to reevaluate.

    The biochemistry that your low carb diet is based on is just not right. Insulin, while necessary for fat storage, does not drive it, period. Insulin’s action in the body is almost entirely driven by the brain. It is the brain that regulates the secretion of insulin by the pancreas. It is the brain that regulates glucose absorption in response to insulin. It is the brain that regulates the passing of fatty acids into and out of fat cells. To the extent that low carbohydrate diets work, they work because of their effects on the brain.

    • In the face of what new evidence? I’m not aware of any new evidence that unequivocally proves the brain regulates insulin secretion and glucose regulation. Until I do, I’m going to stick with what I’ve learned in my 30 years of clinical practice.

      How do you come by your information that you state with such authority?

        • Judging from their abstracts only, the papers cited by Dr. Guyanet aren’t as unequivocal as it sounds from Geoff’s post. That is, the papers indicate that “a role” is played by the CNS (Central Nervous System) and hypothalamus, etc. in the action of insulin. However, regardless of how large a role the brain plays, it is reduced to near irrelevance in most clinical or practical settings. To use the recently overused metaphor, if you go after the lowest hanging fruit — carbohydrate restriction — a lot of things get better for a lot of people, without having to resort to the more difficult and nebulous brain readjustment occasioned by food reward, will power, caloric restriction, what-have-you.

          I would guess that the non-Kitavan part of the world got itself fat from consuming sugary and farinaceous foods and not from eating too much prime rib of beef. a highly rewarding food, or tasty at the least, nor from eating butter all day. Frankly, it’s sugar that appears to me to be the common denominator in all truly “rewarding” food scenarios. Of course, the floury foods are all grain-based, primarily wheat, which are conspicuously absent from the Kitavan dietary. So, for these people, the non-Kitavan fraction of the world, the low hanging fruit in their treatment scheme is carbohydrate restriction. It seems to be the way to go if the hundreds of thousands of people that have been helped to lose weight and improve their health by carb restriction can be indicative.

          The approach just works, but the ado these days on the Interwebz; the “Great Carb Schism” (good one Sam) — reminds me of the joke where French scientists are discussing a new process with the American inventor and they say to him, “Fine, you’ve shown us that it works *in practice*, but does it work *in theory*?” Another analogy I’ll throw in to the mix: if a smoker contracts emphysema from cigarettes, which is practically the only way to get it, a responsible MD would not likely tell the patient to stop all smoking, but say that it’s okay to now smoke pot, or to continue to smoke pot. (Any MDs reading can correct me on this one, please.) So, similarly, the carbs that helped to promote overweight and metabolic syndrome in the first place may not have been the starchy tubers of Kitavan fame. But, once a person is there, these foods, too, may contribute to the worsening of the situation or, if not, at least not aid in improving things.

          • reminds me of the joke where French scientists are discussing a new process with the American inventor and they say to him, “Fine, you’ve shown us that it works *in practice*, but does it work *in theory*?”

            I laughed out loud at this.

            Ever since Taubes made Guyanet’s career, we are now in Paleo 2.0, which is only superfically about “starch isn’t so bad.” What it’s really about is, “Taubes is a meanie, therefore every random rat-extrapolation of our dear offended post-doc is now Science.”

            And since life is just “High School with money”, Eades’ friendship w/Taubes means Eades can’t lunch with the cool kids any more.

            The camp-following that’s been going on has been off the charts. Kurt Harris has now anointed Guyanet nothing less than the utterly reliable source on nutritional science. (I suppose Kurt decided to strike “El Grande Mucho Mas.”)

            And MRE writes a great post with actual science in it? It’s met with silence, other than a snarky psuedo-‘rebuttal’ from Melissa that is full of ‘tude, but really data-free.

            Nevermind that the number of weasel-words in
            What Causes Insulin Resistance could make your head spin; the fact that Eades has not immediately accepted Stephan’s what-if as fact marks him as out-of-touch.

            Meet the new boss. Same as the old boss.

          • A very nice summary in a humorous way of what is taking place. I’m trying to stay out of the fray, mainly because I barely have time to post much less involve myself in vitriol that is sure to go nowhere. Thanks for the support.

          • @Jack uRsooo funny! But personally, I am not really interested in creating insulin resistance in a lab. I’ll go with Dr. Eades 30 years of clinical experience. Theory is very nice, but eventually things will either have to work or not work and “you have to get your head out of the boat” for that to happen.

          • Very well put, Jack, VERY WELL PUT!

            I used to think quite highly of Harris and Guyanet; but since the latter dreamed up his “reward theory”, and Harris BOUGHT into it, I have no use for either. I deleted my shortcuts to their blogs.

            Theory MUST come first, ahead of ALL else. Facts, we don need no stinkin facts.

            Thanks for YOUR blog, Dr Mike. I understand you have a life outside of it and that it must take precedence over your blog. But I do read all that you write and greatly appreciate it, and most of the comments, too.

          • I don’t think Guyanet “dreamed up” the reward theory. He’s just pushing it. Search PubMed for “food reward” and “dopamine.”

          • My take on it is that food reward is what Dr. Eades was referring to when he wrote, “The combination of oil and carbohydrate […] has a taste and mouth feel that humans love, and, consequently, are driven to eat too much of it. No one binges on butter (an oil) all by itself, but add some sugar to it, and you’ve got frosting, which everyone loves and eats to excess.” I posted that on Stephan’s site, and the response affirmed that that’s part of what he’s referring to. I think it was J Stanton at who criticized it as being too nebulously defined, and I can see that as a valid criticism. It’s basically a big umbrella for foods that are eaten addictively, with multiple factors responsible for that addictive nature.

            I also posted that, for me, there’s one addictive food that is perfectly natural and paleo: nuts. If I sit down with a bag of organic raw nuts, I’ll mindlessly stuff my face with them. I was asked why that might be the case, and I didn’t have an answer. But, I just now did a quick glance around NutritionData, and the nuts I tend to buy, almonds and cashews, are significantly higher in carbs than other nuts (15% and 23% respectively). Sure, that’s half the carbohydrate of potato chips, but I think they still qualify as addictive fatty carbs.

    • “but it is clear that you are still firmly in the low carb camp”

      that’s the funniest thing I’ve heard all day…

      I may be missing something about the Guyunet theory, but every time I read that “the brain regulates”, my gut response is “So?”

      How does the brain regulate secretion of insulin by the pancreas? Does the nervous system somehow get wind that there is sugar in the digestive track and so sends word to the pancreas to secrete insulin? And when does the pancreas know when to stop? I thought it was driven by “chemical messengers”, but if the nervous system plays a role in delivering the messages – the brain might “know” what’s going on down under – it seems that it would still work as described in the insulin-drives-fat theory. I don’t know the ins and outs of how this all works, but to assert that the brain is involved seems obvious and unnecessary to me.

      It would follow – with the chemical messenger theory – that you need to provide the pancreas, et al, with different messages in order to get the brain to regulate it all differently. You can’t “tell” your brain not to want carby foods if you had recently been eating carby foods – the messengers are in there (swings in blood sugar levels) already. You will want to “reward” your brain with more sugar to bring the levels back up. Why is this so new and groundbreaking and why does it discount the insulin theory?

      Like I said, I realize I don’t know the ins and outs, so if anyone could enlighten me on this, I’d appreciate it!

      • @Kristen, I know this won’t answer your specific question, but I thought I’d put this here anyway as it’s somewhat relevant, although tongue firmly planted in cheek … (Hell, I don’t post much and since I’m away for Christmas holiday starting tomorrow, I figured I’ll do my annual posting today. I don’t mean to hijack your thread.)

        If we take the various anti- low carb/ancestral/paleo-framework dietary advice that abounds today in the blogosphere, which is mostly that these dietary schemes are deeply flawed (but they work -ed). This concept is evinced by a variety of population groups that seem to thrive while not following any of the said low carb, ancestral, or paleo foodways.

        Thus, we would have the following dietary protocol (just four easy points!):
        1. Eat plenty of rice and soy; this advice clearly is from all of the mysterious “healthy Asian cultures” that eat rice and soy all day. (They are mysterious because one wonders where they’ve all gone; not the rice and soy eaters, but the healthy ones.)
        2. Eat lots of pasta, bread, and olive oil; which is, naturally enough, according to the mythical “Mediterranean Diet”. You could also call this the “Unicorn Diet” as it’s kind of similar to what might exist, but not exactly, and significantly, never has been.
        3. Eat a vast amount of starchy tubers. Of course, this advice is thanks to the divine race of Kitavans as well as, perhaps, Lucy and her ilk. (Those pesky pre-humans.)
        4. And, finally — and this is important — all the above must be accompanied by red wine and cigarette smoking, the latter of which is found in varying amounts — but all greater than in unhealthy North America — in each of the above cultures, most especially in the magical isle of Kitava.

        One can easily see, I am sure, that merely by adopting the (rewarding?) foodways these diverse cultures use, it should be no problem being super healthy!

        • You forgot about the cigar-smoking, whiskey-drinking centenarians! LOL

          I was thinking later that what I’m missing is probably that Guyunet’s theory is that there is some “feel-good” chemical in the brain that makes people overeat certain foods?

      • “How does the brain regulate secretion of insulin by the pancreas? Does the nervous system somehow get wind that there is sugar in the digestive track and so sends word to the pancreas to secrete insulin?”

        Actually yes. The gut has nerve endings. Shocking, I know… The better question should be, how does the pancreas get wind of sugar in the digestive tract if not via the brain?

        • “The better question should be, how does the pancreas get wind of sugar in the digestive tract if not via the brain?”

          yes yes yes…That’s why I can’t figure out what Guyunet is on about!

  43. Dr. Eades,

    It’s so obvious that God created us to be omnivores that I find all this debate about whether we’re naturally vegetarian or carnivorous superfluous. You and your bride have done the world a good service with your books, by debunking vegetarian food bigotry; but every confident assertion about prehistoric man’s diet is presumptuous since prehistory is just that–pre-history. Biblically speaking, man was an herbivore before the Flood and an omnivore after. See Genesis 1:29 and 9:3

    Blessings, Richard Kirby

    Richard Kirby

    • Such a solid response…and here I thought we were talking science. How about we keep our science out of religion (like carbon dating showing the Shroud of Turin is fraudulent) and religion is kept out of serious discussions of reproducible, scientific data.

    • …and then there are the multitudes (including most of those who’ve ever lived, and now live, on the planet) who totally reject Christianity, and the bible as the word of their god. They believe that evolution has resulted in whatever pre-history (an absurd term) has occurred, with natural selection having led to what we are today.

  44. Thank you for your most informative post. I have long wondered how stable isotope measurements were taken and how they could reflect diet. (It turns out that I was also unduly skeptical.) Your explanation was clear and most helpful. Could you tell me

    1. Since sea levels are much higher since the last major glacier retreat, I would expect only to find human remains that were well inland during previous epochs. That might induce a bias. We would be much more likely to find only the bones of those who were eating inland terrestrial prey. But many bones are dated at earlier than the last major glaciation. Has any attention been paid to this issue when reporting isotope analysis?

    2. If so, have these results been reported in a form that is accessible to the average neophyte like me?

    3. What sorts of errors are predictable when using a mass spectrometer? Do you know where I could find this information?

    4. Have any remains been analyzed from near the Great Rift Valley? And do they suggest a preponderance of fish consumption? (I’m thinking of the Aquatic Ape theory.)

    5. Are there any other known factors that would alter stable isotope ratios?

    I hope you, Mary, and all of your readers have a wonderful Christmas and New Year.

  45. Juan, I’m digging your replies; those are some good points.
    Ananda and others have asked “what about the gatherers?”.
    Here are some nutritious foods gatherers can gather while hunters hunt:
    grubs, termites, shellfish, eggs, nuts, seeds, pond fish, frogs,
    as well as mostly low-carb veges, berries, wild-type fruit.
    starchy root veges in most places are a product of cultivation. I think that paleolithic man in many places did cultivate roots (in a rough and ready way, at least by returning to and caring for and possibly re-seeding areas where they grew) long before the year zero of grain (and 12,000-10,000 yrs ago is the FIRST neolithic grain culture, others are much more recent; the 10,000yr figure gives a false, indo-eurocentric idea that grain is older than it is; 3,000-1,000yr may be a better global average date.)
    But those roots were not comparable to potatoes or yam or taro or any traditional starch source produced by cultivation.

    • George, thanks. You’ve got it! I believe that the definition of the Neolithic does start with the first known cereal grain based culture. This is significant, as that only happened in a small part of the Paleolithic world. Up until then, and elsewhere, whatever kind of proto-agriculture might have been practiced by paleo people, it didn’t include any cereal grains, or very, very little. Cereal grain cultivation is the sine qua non of the Neolithic.

      Many Paleo detractors (Paleo-poo-poo-ers?) I have run across say things like “it is not true that Paleo Man did not eat grain.” Well, duh! Someone invented agriculture, after all. But, as we are pointing out (for those who may need the pointing out) it was in a small region at first. Cereal grain usage never characterized any Paleolithic culture before then, since if it had, then that culture would have been the start of the Neolithic! So we are left with the logically obvious conclusion that cereal grain consumption did not form part of our evolutionary diet going all the way back to the beginning.

  46. regarding glycation products, it may be that these serve a useful adaptive purpose outside of aging or disease states (comparable to uric acid, perhaps). Methylglyoxal (a ketone glycation product) is the active antibacterial and antiviral agent in manuka honey.

    • Geroge, interesting post. AGEs are an interesting topic, however, the research on them (and measuring them) is fraught with issues. I am looking at them in my lab (and how to produce them) and it’s amazing how little we actually know. They are often synonomous with anti-carb (wherther appropriate or not), and I think because of this, good science on them has been held at bay. They may kill bacteria and viruses, but odds are they wreck havoc on us as well (likley more so with endogenous production, though exogenous consumption may be a source). I wish more data on them would come out.

  47. Dr Eades,

    I am desperate to find a solution to my problem which seems like it is definitely tied to diet. I have been eating a low carb diet for two months. However, after eating i always have to run to the toilet, where i have liquid gushing out of my backside or watery stools. This happens even when my meals are not too high in fat. My coffee and alcohol intake hasn’t changed since starting this diet. The only difference is that i am eating larger amounts of certain foods namely animal products and eggs. Regardless if a meal contains a lot or no veg/fruit, i still get the runs. I have been to a doctor in the past few weeks. They gave me meds. On the days i took the meds, i was free of the squirts, but as soon as i went off them, the squirts returned. I don’t want to give up this diet, because it has helped my so much in other ways, including increased energy, mental clarity and strength. But, the squirts daily cannot be healthy. Just today, i though that eggs could be the problem, seeing as i am eating many more that i would have before embarking on the diet. I will cut them out for a few days and see what happens.

    Perhaps you have had patients who experienced something similar to me, and therefore you might have suggestions, i hope. Or, maybe some of your readers do.


  48. Just an update on my previous post. my diarrhea has subsided, without the aid of meds. I think i may have found the cause – egg shells. i’ve been eating a lot of eggs. some days i didn’t feel like peeling the egg shell from hard boiled eggs that i would just eating the shell as well. since i’ve stopped doing this one week ago (when i realised that it could be the root of the problem) the squirts dried up and have not returned. Funny, though, i recently read that egg shells are rich in nutrition, namely calcium.

  49. Dr. Eades, I’m a big fan of your web site. I’ve learned a lot from it, and I refer other paleo dieters to it regularly. I have a lot of sympathy for your position here; on the paleo forum I frequent, I feel like I’m constantly fighting a rear guard action against the “sweet potatoes are okay” crowd – as you say, many people seem to think “paleo” means anything except grains.

    That said, I’m absolutely in the camp that “paleo is anything that isn’t neolithic” – or more broadly, that isn’t after the broad spectrum revolution. The fact is, though, that starchy staples like sweet potatoes and potatoes have just as long an agricultural history as rice and wheat. I think the “only wheat is bad” viewpoint comes from cultural prejudice: western culture thinks of wheat as the basis of agriculture, and ignores the equally ancient – but equally neolithic – agriculural traditions of more tropical areas that concentrated on tubers like yams and sweet potatoes.

  50. Hi Doctor,

    Since reading the 6 Week Cure two months ago, i’ve been experimenting with an all meat diet, in which i eat a lot of meat daily cooked medium rare and eaten with the fat. I feel great, except that i experience a lot of twitching in my calves and to a lesser extent my thighs. I don’t eat dairy, but i do eat a lot of bones and egg yolks. I regularly salt my food with sea salt. I often drink quality cocoa.

    Even though i do not eat dairy, given that calcium causes contractions, would that suggest that my problem is not a deficiency of calcium, but likely of its counterpart magnesium, which is a relaxer? I gather that i get plenty of potassium from animal products. If you were to recommend only one mineral for me to try supplementing with, which would it be?

    • Given that I’m clueless about your situation beyond the little bit you’ve told me, I would have to say my favorite mineral recommendation is magnesium.

  51. Generally, how much insulin and carbohydrates can the average human tolerate before starting to get fat, assuming that this human is mostly sedentary?

    Happy new year Dr. Eades!

  52. I also love reading your posts, and judging by your reader replies, so do many others. I just wanted to comment that although the nitrogen isotope reported in the papers is a high trophic level footprint, this can only tell us about the protein in the diet. The protein level was either high, or plant sources of protein were not used to the extent that animal sources were. It doesn’t require a very high level of animal protein consumption to obliterate the protein footprint from plant foods. You do mention this, but I think it’s important to state that isotopes do not necessarily confirm a meat heavy diet, only a diet that includes significantly more protein from meat than from plants.

    • I agree. But animal protein is accompanied by animal fat, and we know from various hunter/gatherer groups that have been studied that the fatty parts of animal carcasses was the most favored. Since the area in which these stable isotope studies were carried out teemed with large animals at the time these studied humans lived, and since we know that the carcass fat percentages are higher the larger the animal, it stands to reason that the high animal protein levels demonstrated by stable isotope analysis would indicate a high consumption of fat. As we all know, fat has a high caloric content. So if you accept the notion that the high protein means high fat intake as well, there probably wasn’t a lot of room calorically speaking for much plant carbohydrate. But, having said all that, the title of the post asks if we were meat eaters of vegetarians, and the stable isotope analysis would seem to confirm beyond much shadow of a doubt that we were indeed meat eaters.

      • I guess whether we were vegetarians or not is not in question. We are definitely not. Even chimpanzees are not.

        The real question is whether we ate or did not eat much carbs. A large part of the paleo believers think that we evolved eating mostly meat.

        There is a growing group of paleo adherents that thinks that carbohydrate consumption varied a lot during the paleolithic period, depending on food variability over the year and regions.

        We of this group think that our body works better if we do have the variability in the diet, rather than a constant low carb diet. We actually prefer low carb diets but avoiding the very low range of below 50gms/day, except on occasions as part of the variability.

        I am not sure the archaeological evidence is good enough to specifically prove that a high meat diet was the diet of most paleolithic people. The evidence is skewed towards temperate climates as those tend to hold the archaeological remains better. Temperate climates also have a less widespread vegetation, and would support a higher meat diet, compared to tropics.

        • Amanda, evidence would be an improvement over a theory about why the evidence doesn’t exist.

          Theories seem to be enough for the Whole Health Source crowd, though.

    • Hi Stephanie I appreciate your point of view and judging by the graph Neanderthals were more carnivorous than we were. So do you think that would put us in PHD carb ranges possibly? Where can I find more info on this stuff? Cheers, Colin.

  53. So do you think that by eating all of that meat that any of our European paleo-ancestors lived long enough to develop the inevitable heart disease? Doesn’t really matter if they did or not. Regardless of what they ate thousands of years ago (which, by the way, was mostly freshwater fish for the early modern humans in Richards’s study — Neanderthals were the ones who ate terrestrial animals), there is plenty of evidence that eating a vegetarian diet is nutritionally sound and healthful TODAY. And it’s also a more environmentally conscious way of feeding yourself. What about the Seventh Day Adventist Study? A community that is vegetarian with a longer average life expectancy than the rest of the country.

    It’s very nice that you want to be like your paleo ancestors, except that they lived in completely different circumstances thousands of years ago. Circumstances that you don’t live in today, and can’t even if you tried. The world’s changed. Hey, maybe if our ancestors had continued to eat like their paleo ancestors and hunt meat instead of settling to grow grain and develop culture, we’d still be running around hunting and fishing just to survive instead of typing on these fancy machines in comfortable, warm offices with artificial lighting and everything else that’s made humanity live more comfortably since the development of agriculture and domestication of animals.

    • You don’t have a clue what you are talking about.

      For instance, the Seventh Day Adventists live very conservative lives. No smoking, no alcohol, no risky behaviors generally. Excellent community support in life’s travails. Now, if you correct for those behaviors, they don’t show up so superior. In fact, IIRC, they have rates of heart disease higher than the population at large. Not much HDL in those veggies, you know, and all that soy.

      Not sure about your source, but I’m guessing there wasn’t much fish in the plains of Africa as we came of evolutionary age.

      The question you fail to address in regards our comfort is, “Are we happier?” All research I’ve seen on H-G groups would indicate that the answer is a resounding, “No!” They typically have a lot more leisure time, time with family and friends, no rat race.

      If your concept of a vegetarian diet is ovo-lacto, there isn’t much difference between you and paleo. But if you are eating grains, I hope you like your inflammations.

    • I started eating more meat when I became “environmentally conscious”.

      The current way of producing food is not efficient. I am pretty sure that the current population is not sustainable for long. We will kill off most of the environment, and then die of starvation. Hopefully in a century or two, enough people will survive so that some can live on.

      We cannot eat all of the plant, its not possible we are not designed for it. We need some animals to eat those parts of the plant, and produce energy for us. That is how we make the plantation more efficient.

      Secondly, the plants have to eat something. The current method of providing them artificial fertilizers is not sustainable. Animal manure and animal remains are the best way to provide them the food that they require.

      If you are ENVIRONMENTALLY CONSCIOUS then you will learn something about how plants grow, what they need. How we can utilize the energy provided by the sun more efficiently. Rather than parrotting the party line, written by the interested parties. There is a whole ecosystem of leeches feeding on the mis-information fed to us.

  54. Paleo Grandpa,

    Unfortunately vegetarian diets are not more environmentally conscious.

    Also, I agree with most of your latter comments, however there is no reason why we can’t “still be running around hunting and fishing just to survive”. I do it (well on my free time) and it is, in fact, more environmentally sound!

  55. Dear Paulie,

    No, you don’t remember correctly. Seventh Day Adventists are less likely to die from cancer and heart disease, period, even if you compare non-smokers with non-smokers in both groups. And apparently, people who drink at least a moderate amount of alcohol actually statistically live longer, not shorter lives. So yeah, the Adventists should be dying right off with their inflamed, non-drinking, soy-binging ways, but they’re not. Why do you need to consume HDL? Cholesterol is not a nutrient, your body can synthesize it without you ingesting it, and what does that have to do with soy? Maybe you, sir, are the one who is confused.

    Why my source is Michael Richards!! The same person the article above is about: Richards, M.P. and E. Trinkaus (2009) Isotopic evidence for the diets of European Neandertals and early modern humans. Proceedings of the National Academy of Sciences, USA 106:16034-16039. Maybe you, sir, should read the article I commented on before you decide to comment on my comment. You know, so you understand what’s being said before you get all snippy.

    Yeah, maybe the H-G’s had it all figured out. Their lives ruled and ours blow. Except nobody seems to be rushing back to those “happy” days because…hm…I guess it is kind of nice to live with the comforts of the modern world. And if our modern word makes us so unhappy, Paulie, then why don’t you stop posting on this blog and go and be an H-G like the Bush people in Africa? But see, the fact is, you would never have even thought of any of this information on your own if you were an H-G because there wouldn’t be modern medicine or research to actually figure out what kind of diet is better or more like the paleo man who you so desperately want to imitate. Yup, you would’ve been running around after your food. And that’s about it.

    Caveman Doc — I wish I knew how to hunt. Maybe it is better, in a restricted environment, you know? Without millions of other people also hunting for the same few wild animals. I honestly don’t know enough about the environmental factor besides what I’ve heard offhand. But the way it seems, is that it’s just unsustainable either way with the amount of people living on this planet. Sucks.

    • My name isn’t “Paulie.” I use my real name instead of hiding behind a pseudonym.

      Stop being condescending.

    • In regards to your unsustainable comments, we are likely in agreement. However, that’s the double edged sword of grains and civilization. With theories ranging from quick and storable forms of food favoring population expansion to opioids in grains “numbing” people and allowing them to exist in crowded areas, it allows me to type this on my computer in the comfort of my own home, but brings with it disease, crowding, and overpopulation leading to potential unsustainable societies. There is no easy answer to whether one is better than the other, and this is why I try to follow several caveman principles while living in modern society. However, I am well aware that the principles I follow are my interpretation of those which are most important.

    • @…Paleo Grandpa
      No-one in the Paleo community is advocating rushing back to the good ol’ days. That is one of the numerous straw man arguments that ill-informed vegetarians and/or conventional thinkers throw out there (for some reason). It simply is a false representation of the “paleo” idea. And, although it isn’t just one thing, whatever the “paleo” idea is, it is not an attempt to recreate some idyllic prehistoric hunter-gatherer lifestyle. If that is what you think, you are simply mistaken and should look more carefully into the literature. That does not mean there aren’t individuals who might want to do just that, it means that isn’t part of “movement” as a whole or part of its meme.

      As you point out, early modern humans seemed to have used a much broader food base in Europe than did their near relatives, the Neanderthals and, presumably, their own ancestors who came out of Africa more than 50,000 years prior to the time of the groups studied in the Richards et al. paper. (They were Mesolithic people). Still and all, neither early modern humans, Paleolithic era humans, nor proto-humans were vegetarians. This is well established in anthropology and archaeology. I don’t know why the 7th Day Adventist study keeps getting trotted out as if it proves anything at all other than that 7th Day Adventists tend to live longer than the average American. There are many other groups in the world who live longer than the average American, and they are not all vegetarians.

      The “humans are fish-eaters” trope is not a straw man argument as is the cave-man reenactment, but rather like the vegetarian myths, it’s a red herring. :)

      And by the way, you are coming across as far more snippy than anyone else so far.

  56. Juan — my point was that vegetarianism is a nutritionally sound diet today, when most humans are not scrounging for food just to survive. I brought up the Seventh Day Adventists as an example; their longevity and generally lower mortality from “diseases of civilization” just seems to imply that their diet doesn’t appear to make them any more sick even though they eat all of those supposed inflammation-inducing carbs. That was all. Just used them as an example.

    The above post claims that the early modern humans tested by Richards ate a lot of fish and were not vegetarians. And I’m saying, so what? Doesn’t mean we can’t be, and it doesn’t seem to hurt us if we are. From what I have understood so far about the paleo community, you don’t say much else besides what everyone else does (about eating whole, nutritious food, exercising, resting) except you want to eat more meat because your ancestors supposedly did and demonize carbs as the cause of modern diseases and inflammation. And that just seems silly.

    Mostly because our more recent ancestors, those of the past ten thousand years, lived in agricultural societies, where the main sustenance was some sort of native, energy-dense crop. It just seems that advocating one diet and demonizing carbs doesn’t make much sense given that plenty of people, historically, have been healthy while eating carbs as their main source of energy. And furthermore, that exact agriculture is what’s led to you being around today! So why talk shit about crops that have nourished our human ancestors and helped give rise to stable civilization? And then try to advocate a supposed diet from thousands of years ago that has not shown to be healthier?

    • @Nothing wrong…

      I think the piece you’re missing in all of this is how different foods affect the body. The reason people have “gone Paleo” is because our bodies have not evolved to be able to handle carbs well. There is a new book out, “Wheatbelly” that I hear is very good at describing how grains are not good for the bod. Ancient cultures who had grains in their diets also modified them through fermentation and other means to make them more digestible.

      Perhaps the effects of carbs on the body, or the direct link between the two, has not been seen until recently because carbs provided extra calories during times when people couldn’t walk into the grocery store filled with food and medical practitioners couldn’t discern why disease happened with tools they had at hand.

      Human beings have flourished in spite of many suboptimal practices.

    • @nothing wrong…paleo grandpa
      It’s funny that you say “why demonize carbs as the cause of modern diseases and inflammation.” and that it’s “silly” to think that they do. Have you read any of the literature in this area at all? The carbs in question are, of course, principally the gluten grain-based floury products and fructose laden sweets, all of which have been on the rise for the past 50 years (also chemically extracted industrial seed oils). But, even before that very recent history, whenever these elements of the diet are removed, most of the modern inflammatory and autoimmune conditions, the diseases of civilization, seem to either dissipate or to go away altogether. Just because something has been used for thousands of years does not mean it is optimally healthy, nor does the fact that agriculture allowed civilizations to flourish in the first place– and thus that we are here today — have any relevance to the concept of healthy and nutritious eating. Besides, it is in the very early Neolithic agriculturalist groups that the Diseases of Civilization first started showing up in the fossil record, as did shortened stature and loss of robustness. The whole notion of paleo is not “what did we eat for the past 10,000 years, but rather, what did we eat for the hundreds of thousands of years before then, that made us into who we are.

      The paleo idea does not advocate that one must eat a lot of meat but that it is okay and, indeed, natural to eat animals. Go ahead and eat primarily vegetation, though, as that also perfectly in keeping with a paleo diet. So often when discussing dietary regimens, we hear nothing but “fruits and vegetables” as if it were a magical mantra, and we are conditioned to think that the less you eat animals, the better off you’ll be. That may be true, but also unashamedly adds animals to the mix and doesn’t vilify animal-based food. Actually, a lot of people who switch to paleo report eating more vegetables than ever before, not necessarily more meat. That’s just a silly, knee-jerk assumption that veg*ans seem to make all the time. The calories you lose from giving up the now commonly regarded Neolithic Agents of Disease; sugary and farinaceous foods (grains) and industrial vegetable oils, need to be replaced by something. In the paleo community some of those calories may come from slightly more meat, but most comes from more high quality fat and from vegetables.

  57. I am a touring musician am have always struggled to do low carb. Mr Eades would you have guidance as to where I can get a low carb sample menu? I don’t want to just “Google” one per say. I want to learn from you.

  58. Dr. Eades, I think you’ll find Chris Masterjohn’s newest post interesting.

    He talks about how the leading biochemistry textbooks have it wrong; we really can make glucose from fatty acids through multiple pathways. In addition, under conditions of low carb consumption, we actually start to actively spare glucose.

    Chris is too polite to say it directly, but he blows a pretty big hole in the arguments of the Guyenet/”healthy starch” clique.

    In my opinion, for all the people loudly mouthing off about nutrition, there’re very few with the actual chops in biochemistry to understand what’s really going on. I count you, Chris, and Peter at hyperlipid among this very small group… and none of you are shouters.

    A little knowledge is a dangerous thing. So, apparently, is a few archaeology classes.

      • First time I heard of them as well… I was wondering how exactly can they get that accurate count of the fish that is being killed… if you see the counter on the right side of the screen… somebody must be very good at counting that fast, and everywhere in the world.

  59. Dear Mr. Eades,

    Do you have any comments to a recent study: “This value is larger than usually assumed in palaeodietary studies, which suggests that the proportion of animal protein in prehistoric human diet may have often been overestimated in isotopic studies of palaeodiet. Am J Phys Anthropol, 2012.”