Pages

Monday, May 16, 2011

Who Said Paleo Diet Had High Fat Percentages? Part 1


In 1988, physicians S. Boyd Eaton and Melvin Konner, and Emory University anthropologist Marjorie Shostak published “Stone Agersin the Fast Lane:  ChronicDegenerative Diseases in Evolutionary Perspective” in the American Journal of Medicine.  They expanded this paper to produce the book, The Paleolithic Prescription.  

By the way, Shostak lived among African hunter-gatherers for two years, and wrote the book Nisa: The Life and Words of a !Kung Woman.


 In these works, Eaton et al provided their estimates of the fat contents and composition of stone age diets.  They based their estimates on known nutritional values of 43 different wild game animals and over one hundred species of plants consumed by modern day hunter gatherers. 


The data on nutritional value of wild game came largely from Ledger, who dissected 220 different animals of 16 species. [1]  Ledger worked in the field of zoology, and published this data in a zoological journal, for the purpose of comparative studies of African mammals, so we have no reason to suspect that he had any interest in advancing any nutritional dogma. 

We have a very important reason to focus on the nutritional value of African mammals.  The human genome evolved to the present species, H. sapiens sapiens, in Africa, as an adaptation to the African environment, over the course of 6 million years (from the divergence from the common ancestor of great apes and humans).  Of 6 million total years of hominin evolution, the 50K years that have passed since humans left Africa constitutes only eight-tenths of one percent. Virtually all of human evolution took place in Africa, so we can expect our baseline physiology to be more adapted to the diet available to our African ancestors, than to any human diet that emerged after the African exodus in northern environments. 

The animals included goat, Cape buffalo, warthog, horse, wild boar, antelope, beaver, muskrate, caribou, moose, kangaroo, turtle, opossum, wildebeest, Thomson’s gazelle, kob (waterbuck), pheasant, rabbit, impala, topi, deer, and bison.  The fat content of meat from these animals ranged from a low of 1.2 g% in kangaroo, to a high of 5.4 g% in wildebeest. 

In 1964, Ledger and Smith reported the results of their dissection of 40 Uganda kob, 10 mature and 10 immature of either sex.  They found that “all kob had a low level of carcass fatness (maximum 6.2 percent), associated with high carcass yields”  and when compared to steers, the “ratio of fat to lean showed a higher proportion of lean in kob carcasses. The food value of kob per pound liveweight is superior in terms of animal protein and inferior in terms of calorific value to that of steers.”[2]  Indeed, a modern grain-fed steer has around 25% of the carcass as fat, making it 4 times fatter than the kob.

Eaton et al assumed a diet providing 35% of weight from animals, and 65% from plant, and a total food consumption of 2250 g (nearly 5 pounds) daily to provide around 3000 kcal daily.   I consider this a very reasonable amount of food.  I have measured my own food intake many times and when eating 65% plants and 35% meat, it consistently has ranged between 4 and 5 pounds.  The following provides an example day on which I ate 4.7 pounds of food, which I published in The Garden of Eating:

Click for larger version


Ledger’s analysis of wild game meat showed that on average a 100 g portion provides 133 kcal, 22 g protein, and 4.3 g fat, 32% of which, on average (based on 17 species evaluated), occurred as polyunsaturated fats (ranging from 20-60%, largely as linoleic acid, omega-6), and well under 40% saturated fats.  For comparison, four types of untrimmed domestic meats (beef, pork, lamb, ham) can supply an average of as much as 386 kcal and 29 g fat per 100 g, and average 45% saturated fat, and only 7 percent as polyunsaturates.

To estimate the contribution of wild plants to fat intake, they used an analysis of 36 wild foods eaten by the Hadza, the San (Bushmen), and other African tribal groups, which indicated generally a very low fat content, of which 39 percent, on average, occurred as polyunsaturated fat.

Isolated fats in Paleolithic diets

Hunter-gatherers do not have any fluid seed, nut, or fruit (olive, avocado) oils.  I don’t think we can consider olive oil, avocado oil, or coconut oil paleo foods, since production of these fats requires technology not available in the stone age.

Like modern !Kung, Paleolithic hunter-gatherers living fifty thousand years ago also did not have pots necessary for rendering, i.e. refining and isolating, animal fat. Nor did they have cream or butter.  Based on this, I have come to realize that I can’t consider isolated lard or tallow or similar refined, animal-derived fats “Paleolithic” foods. We really can’t consider any isolated oil, whether animal or vegetable, a paleo food.  

Actually,  after thinking about this for some time, I have come to realize that all isolated fats belong to the class of refined foods; fragments of the whole from which they came.  I have also realized that adding these to the diet constitutes a significant deviation from ancestral nutrition.  Using the paleo paradigm, because these foods deviate significantly from anything had by humans 100 thousand years ago, we have to consider them suspect from the get go, guilty until proven innocent.  

Effects of Paleolithic cooking techniques on dietary fat

If you have television and want to see how hunter-gatherers cooked meat, watch the Bizarre Foods episode titled “Adventures in the Khalahari,” in which Andrew Zimmern visits the Ju (!Kung, San) people.  They either throw the meat directly into the fire, or bury it in the ashes.  Similarly,  as reported in the following passage, Australian Aborigines cooked meat by burying it in a pit. 


“A large fire was made in a depression in the sand, and stones and shells were heated. Small green branches were placed on top of the stones and the wallaby was flung on these. After 5-10 minutes it was taken off the fire, placed on a layer of green leaves, and the singed fur was removed with a tomahawk. The first cut was made horizontally on the ventral surface at the level of the anus, and the next on the dorsal surface along both sides to sever the leg muscles.  Another cut was then made from the anus to the neck.  The viscera were pulled out; and the kidneys, liver, heart and lungs, and the omental and mesenteric fat were separated from the rest, and cooked [directly] on the hot stones and coals for 5 minutes [Editorial note: allowing the fat to seep into the fire].   The cooked lungs were used to soak up the blood inside the carcass and then eaten.  The offal was regarded as a delicacy by everybody and a certain amount of squabbling always followed its distribution. The tail was cut off, and during the cooking was put on or alongside the body.  The carcass was laid flat, dorsal side downwards, on the hot stones and ashes and the body cavity was filled with hot stones.  Sheets of paperbark formed a cover over the animal, and sand was scooped out to make an oven. Wallabies weighing 15-20 pounds were cooked for 25-35 minutes.  Everything edible was eaten except the stomach and intestines.  The skull was cracked open to get the brain, and the bones were broken to extract the marrow.”  [Source: Anthropology and Nutrition, vol. 2 of Records of the American-Australian Scientific Expedition to Arnheim Land, ed. C.P. Mountford (Melbourne: Melbourne University Press, 1960).]


In any of these methods, hunter-gatherers lost significant amounts of animal fat into the fire, stones, coals, ashes, or soil.  Indeed, since paleo people didn’t have neolithic pots we really can’t consider cooking in such pots a Paleolithic technique, and I believe it important to notice that cooking meat in neolithic pots results in capturing more of the fat of foods than a hunter-gatherer could capture.  We especially can’t consider frying in fat a Paleolithic diet method. 

Regarding pemmican, consider that one hundred thousand years ago, no human had the technology required to render fat to produce pemmican, even if we assume available African game could have provided the required amounts of fat (it didn't). The invention of suitable pots occurred about the time of the agricultural revolution.  This means that the human genome has probably not adapted to the level of dietary fat that is possible through the use of this technology any more than it has adapted to the use of cereal grains.

In addition, consider that, prior to the 20th century, people used animal fats for many purposes other than eating.  Before the petrochemical age, animal fats were used as lubricants (e.g. grease for axles), for tanning leather, and to make soap, salves, paints, wood finishes, and candles.  Even Inuit used seal oil and blubber to fuel fires and candles.  These uses took animal fats out of the food supply, reducing the potential fat content of the diet.  When petrochemicals or vegetable oils replaced animal fats for these purposes, this increased the animal fats available for food use. 

Discussing cooking techniques appropriate for a Paleolithic approach, Eaton et al comment:


“Roasting, baking, and steaming (water is poured over hot stones as at a Polynesian luau) are techniques used by recent hunters and gatherers and are probably ancient.  While all cooking procedures affect the nutrient content of food, these traditional techniques are relatively healthful.  Baking and roasting reduce the fat content of meat [note: so long as you don’t retain fat of juices] while steaming (in contrast to boiling) minimizes vitamin loss.  Furthermore, none of these methods add fat.  Recently studied hunters and gatherers do not fry their food, chiefly because they lack appropriate cooking vessels….

“Nonstick pans should be used to cut down on fat or oil.  Or, oil can be spread lightly with a paper towel.  Vegetable oil sprays now available achieve the same result mechanically….

“With poultry, remove skin and visible fat.  Defat gravies with a bulb syringe or skimmer.”


So, how much fat did Eaton et al estimate to occur in a Paleolithic diet?

If you take 35% of the 2250 g diet as meat, supplying 4.3 g fat per 100g, you get ~34 total grams of fat.  Eaton et al estimated an additional ~40 g of fat supplied by plant foods 3 percent fat on average), resulting in a total fat intake of about 70 g daily, or about 21 percent of the total 3000 calories consumed.  This would translate to only 42 g of fat for 2000 kcal, and only 32 g fat for 1500 kcal.

If you take 65% of the 2250 g diet as meat, supplying 4.3 g% fat, you get 63 g fat daily from animal food, and an additional 24 g from plant food, for a total of 87g fat.   That works out to just 26 percent of calories from fat, a minor difference from the opposite plant-animal ratio, still very low in fat.  

Because wild game and plants had a relatively high percentage of polyunsaturated fats (~30%) and lower percentage of saturated fats, Eaton et al also estimated a high P:S ratio in Paleolithic diet compared to modern diets, and suggested that this accounted for the uniformly low total cholesterol levels found among hunter-gatherers, ranging from 106 (Pygmies) to 141 (Canadian Eskimos).

Eaton et al concluded:


Late paleolithic humans must have obtained, on average, between 20 and 25 percent of their calories from fat.  Of this, polyunsaturates exceeded saturates; a typical P:S ratio might have been 7:5 (which can also be expressed as P:S = 1.4:1).”


So, it appears that Eaton et al did not have evidence or belief that evolutionary diets had high fat (or low carbohydrate) contents.  Indeed, they stated:


“Between 1910 and 1976, the consumption of fats in the United States increased by about 25 percent so that, currently [1988], fat makes up about 42 percent of the calories consumed by average Americans.  Of this fat, more that twice as much is saturated as polyunsaturated.  This level of fat consumption is unprecedented in human evolutionary experience, and results in diseases that kill us, but that are uncommon in countries where fat represents a much smaller proportion of the diet.  In rural Japan, for example, only 10 to 12 percent of daily calories come from fat (with a P:S ratio of approximately 1:1) and the prevalence of coronary heart disease among the Japanese is only a small fraction of ours.” 


Taking these and other data on the health effects of dietary fat into account, Eaton et al recommended that a modern rendition of Paleolithic diet supply only about 20% of calories as fat, with about 25% of calories as protein and 55% of calories as carbohydrate.  They outline an implementation that provides 19% of calories as fat, 26% as protein, and 55% as carbohydrate.

So it appears that the notion that modern rendition of paleo diet should have a high fat and low carbohydrate content did not come from Eaton, Konner, and Shostak.  

Next in this series, we will see what Michael Crawford and David Marsh, authors of Nutrition and Evolution, had to say about fat in human evolutionary diets. 


1.  Ledger, HP.  “Body composition as a basis for a Comparative Study of Some East African Mammals.”  Symposium of the Zoological Society of London 21 (1968): 289-310.

2.  Ledger HP, Smith NS.  The carcass and body composition of the Uganda Kob.  Journal of Wildlife Management 28(4), October 1964

68 comments:

Chris Sturdy said...

Hi Don,

Didn't Eaton et al. later revise and increase their estimates for fat intake based on the fact that HGs used the entire animal and although unable to render the way we can and do they would get appreciably more fat in their diet via marrow etc.?

Darn you for making me/us think!

Cheers,
Chris

Rudolf said...

Don,

I hope you had nice honeymoon!

as far as we know fire was domesticated 200-400 k years ago. On the scale of 6.000.000 years of evolution it is only 3,3-6,6%. Most of the time of the evolution our ancestors did not have fire. So, are we adapted to cooked foods?

Furthermore, if they ate raw meat, no fat in cooking was lost.

Rikke Rørbæk Olsen said...

This is very interesting.
I have always wondered how to make sense of "as natural as possible" (i.e. game meats) and still eat high fat, as my experience is that game meat isn't exactly like this; high in fat.

Is your suggestion that we change our dietary intake to "conventional wisdom" ratios? (But of course keep the primal sources).

Rikke Rørbæk Olsen said...
This comment has been removed by the author.
Richard said...

Good post. I also wondered why, for example, flour is considered bad since it was refined, but refined fat was considered okay. I agree that refined anything is probably a bad idea.

I've been following paleo-like blogs for over a year now and it seems that speculation on what paleolithic humans eat has gone from one extreme to another, and now the trend among blog writers seems to be very similar to the standard government nutritional recommendations, with the only real exception being their position on grains and polyunsaturated fats. the nutrient ratio recommendations seem to be about the same.

Theo said...

This is exactly why I consume soaked and fermented grains in addition to the normal paleo fare. I think that looking at paleolithic peoples is very helpful, but it does not necessarily give us the recipe for being as healthy as we can be. For example, paleolithic people's didn't live beyond 80, and there is evidence of tooth decay, etc. I also think it is pretty obvious that some neolithic inventions do not cause harm -- pots, rendered fat, dairy, gyms, beds, etc. I might even posit that the acceptance of some neolithic inventions is necessary for the best health and enjoyment of life.

Thank you for these posts. We really need paleo adherents to understand that paleo is NOT low carb. Even the Inuit consumed as much as 10-15 percent of calories as carbohydrate.

I do, however, do not think that having more fats in the diet, as the authors posit, is not necessarily a bad thing. We have several example of populations eating lots of fat and also having low cholesterol and heart disease.

kulimai said...

Hi Don,

This is general query, but seems to me quite relevant for this series and for (both sides of) the implied debate.

How does one connect (postreproductive) health(span) with reproductive success where the latter is what evolution selects for but where this obviously may equally have both beneficial and deleterious effects on the former?

If we cannot establish a reliable connection, then I do not quite see why exactly (apart of course from legitimate academic interest) it would be crucial to figure out what exactly our paleo ancestors ate.

malpaz said...

WOW....just wow, you put up a good argument, excited to see where it leads!

Don said...

Chris,

I'll get to that later. For now, Ledger evaluated the whole carcass fat content, organs and all.

Rudolf,

We actually have good evidence for hearths as old as 1.5 million years.

http://simple.wikipedia.org/wiki/Control_of_fire_by_early_humans

http://www.jstor.org/pss/2743299

Further:

1) The further back in time you go, the less developed the hunting technology. Bow and arrow, for example, did not exist until about 50K years ago. Thus the harvest of animal fat most likely had to be lower the further you back.

2) In producing their estimates, Eaton et al assumed consumption of all the fat in the raw meat, did not account for losses in cooking. So their numbers would apply to an all raw diet; a cooked diet would have even less fat.

3) No matter if eaten cooked or raw, the whole carcass of a wild African mammal had only a quarter or less of the fat in a modern grain fed animal, and less than half of that found in an intensively grass-fed animal.

Rikke,

I myself am doing that.

Theo,

"I also think it is pretty obvious that some neolithic inventions do not cause harm -- pots, rendered fat, dairy, gyms, beds, etc."

I would have to disagree. I don't think that it is "obvious" that rendered fat or dairy products "don't cause harm." On the contrary, I think, and will give my reasons later, that rendered fat and dairy products do cause harm (unless consumed only in very small amounts or occasionally). Pots may or may not cause harm depending on how you use them (retain or not retain fat).

The primitive populations eating "high fat" and having low cholesterol have unique fats and/or do show harm from their diets. Inuit diet was pretty high in fat, but largely marine source, hence very high in omega-3 PUFA. Masai diet produced extensive atherosclerosis in the Masai, although they avoided cardiovascular events, probably for 3 reasons: their dairy fats had higher n-3 fat contents than modern, they always consumed their dairy with lipid modifying herbal combinations (see my post on the Masai), and they were extremely physically active.

Don said...

Kulimai,

You have a good question. I think that most anthropologists accept that longevity promotes reproductive success because grandparents contribute to the well-being of their grandchildren through various means (food, health care, teaching successful survival strategies). But I also agree, at a certain point we have to look at what promotes longevity among modern populations, and combine that knowledge with paleo perspective.

Theo,

In later posts I will further address whether high fat intakes have adverse effects on health. I think the evidence is pretty compelling that excess dietary fat, particularly highly saturated fats, does harm...ranging from obesity to cancer.

Chris said...

After 3 years on a high fat diet,I feel "topped up"and don't want the fat anymore.
In your next post could you touch on fat and insulin resistance?

el66k said...
This comment has been removed by the author.
r said...

nothern people may have been driven to eat more fat to acquire more vitamin D. people in most of Africa would have adequate sun exposure. this would seem to still be a valid reason today.

kulimai said...

Don, thanks for your reaction. I wonder if the grandfather effect can really be significant though in our present context.

A rather imperfect metaphor that nevertheless indicates what I have in mind: Suppose if your car finishes top 2% in a killing race that you *must* participate in, your car is likely to be total junk by the end but you definitely get a shining new replacement. If the car finishes top 10% your old car may still work for a number of years (good also for spares) but your chances of getting a replacement are much reduced. You may choose either strategy. But if these races are repeated many times over a longer time span eventually only owners with the first, more agressive strategy will continue to have cars. The kind that put the special fuel in the tank that makes the car go twice as fast for the first few hundred miles without regard to whether it cripples the engine soon afterwards...

Don said...

r,

Only fish oils serve as significant sources of vitamin D. Check a few nutrition data sources. I have a post upcoming on this myth.

Kulimai,

I appreciate your metaphor, and to some extent I think it valid. I think it especially applies to primitive diets that deviated from the ancestral African. Hunting mammoths and milking cows has allowed people to reproduce adequately in a variety of climates, but this doesn't mean those diets provide the best approach to prevention of chronic disease.

Don said...

Rudolph,

Just found the article I meant to refer to about early evidence for control of fire c. 1.5 MYA.

http://cogweb.ucla.edu/Abstracts/Pennisi_99.html

After the article by Pennisi, read the letter from Ralph M. Rowlett of the Department of Anthropology,
Missouri University. He cites evidence for human control of fire 1.6 MYA. That would constitute 25% of the evolutionary time since the last common ancestor of humans and apes.

nonzero said...

"But what about the French?"

You may be correct in reasoning that our ancestors did not necessarily eat a high fat diet, but isn't anthropological data just a starting point for nutritional analysis? Wouldn't modern day observations trump error-filled reconstructions of the past? Particularly, what of the many observed cultures who eat high-fat diets and suffer less diseases of civilization (french et al)? And what about the lack of any conclusive studies showing a causation between dietary fat (esp. saturated) and pathology? And there are a growing number of people eating a high-fat 'paleo' diet and vastly improving their lipid profiles as well as body compositions, how would that fit into the overall conclusions for dietary recommendations?

I didn't stop eating grains because cavement didn't eat grains, that was just a piece of the puzzle which includes other evidence to support the idea that grains are harmful/not optimal. For the same reason, why should one not eat high-fat just because cavemen did not necessarily subsist on such high levels of dietary fat if there is growing modern evidence that high-fat is healthful/optimal?

Rob K said...

"In any of these methods, hunter-gatherers lost significant amounts of animal fat into the fire, stones, coals, ashes, or soil. "

I have to disagree with this, from first-hand, personal experience. I have many times cooked meat directly on a bed of hardwood coals. The fat loss is not significant in my experience.

Flowerdew Onehundred said...

I have "The Paleolithic Prescription" right here in front of me, and their menu plans include grains and legumes. Cereal for breakfast and sandwiches for lunch!

I find that just a little odd.

solarchaeon said...

Don: "Only fish oils serve as significant sources of vitamin D. Check a few nutrition data sources. I have a post upcoming on this myth."


or pastured lard, according to the WAPF.

http://www.westonaprice.org/abcs-of-nutrition/168-miracle-of-vitamin-d


i look forward to seeing what you have to say.

john said...

I think that there is something to the fact that cultures do prize fatty parts. A while back, Kurt Harris had that guest post that seemed to suggest that the San diet is higher in meat/fat than is typically thought.

One problem is that we can't really study cultures that have "paleo" diets, in the way that most people think of them. Maasai are high fat, but they eat high dairy and very little meat. The Mongolian nomads are the same--have you seen that Bizarre Foods Don--it's maybe my favorite one. Their favorite parts are the skin and fat. Perhaps the Native American or Chuchki are the best examples of the high fat/meat eaters?

On fat type, I've always been skeptical of people's claims of 4% (or lower) pufa with high fat diets including eggs, pork, poultry, avocado, nuts, etc. 4% on a high fat diet would tend to require avoidance of those things. The specific number of 4% is a little shaky, but the theory of low pufa for health is well-reasoned, and the positive experimental results when reducing pufa is clear.

Don said...

solarchaeon,

Check the USDA database yourself:

http://www.nal.usda.gov/fnic/foodcomp/search/

Enter lard, choose Fats & Oils, then choose 100 g.

You will find that 3.5 ounces of lard had 900 kcal.

Second, that database says that 100g/900 kcal of lard provides only 102 IU of vitamin D, not the 2800 claimed by the author of that article.

Don said...

nonzero,

Where is the evidence that high fat is optimal?

I've been in this business for 30 years. I've seen evidence that people can survive and reproduce in tough environments by eating high fat diets. I've seen evidence that the French, eating a high fat diet, don't do as poorly as Americans, but they also don't do as well as the Japanese, particularly on the aging front, but also on the mental performance front (average I.Q.). You can eat high fat and "balance" it with a solvent (alcohol) and have a high rate of liver cirrhosis (check on that in France).

I'm going to go over a bunch of evidence that the high fat advocates simply ignore...not epidemiological either, simple scientific facts and clinical trial data.

Don said...

Flowerdew,

Why? At that time, they concerned themselves with replicating the macronutrient ratios and micronutrient content of a paleo diet. They had not come to believe that specific neolithic foods had harmful effects. In fact, this is exactly the same idea of Weston Price, who believed that we only need to replicate the nutrient profile of primitive diets, not the specific foods.

John,

I love that "preference" argument.

I prefer having an income of $1 million per month. Does that mean that I always have what I want? Of course not.

If you ask many people, they prefer donuts to potatoes. Does that mean that donuts are a healthier option for us than potatoes?Of course not.

People prefer a lot of things, that doesn't mean that they always have what they prefer. Hunters always wanted more fat than they could get. When they got higher fat animals, they loved it...that certainly does not tell us that the human body is built to run on a high fat diet for the duration. Nor does it tell us how often hunters actually got what they preferred.

Grok said...

"I have come to realize that all isolated fats belong to the class of refined foods; fragments of the whole from which they came."

A golden sentence Don! :)

Greg said...

Hi Don,

Rendering animal fat is a common tradition, especially in marine environments where one can come across whales or seals with lots of blubber! This would constitute adding refined fat to a meal. It is an interesting observation, though, that most plant fats could not have been readily separated from the plant.

Also, that Eaton/Cordain study has been laughed at by Stephen of Whole Health Source and Chris MasterJohn on the WAPF blog. I am too lazy to find the links right now. I think you need to apply more scrutiny to that one source.

Any dogma which says fat/carb is inherently bad or good won't stand up to scrutiny. We know the Inuit and other animal food based tribes must have consumed the majority of their calories from animal fat. We know other tribes consume the majority of their calories from carbohydrate foods.

From a nutrient point of view, fat is generally low in nutrients, other than specific fat-soluble components. This is the main reason why I don't eat high fat/low carb. I view this as a modern, cautious approach that would not be necessary for a hunter gatherer.

Greenacres said...

"The fat content of meat from these animals ranged from a low of 1.2 g% in kangaroo, to a high of 5.4 g% in wildebeest."
Does that mean that these meats are as devoid of flavor as skinless poultry breasts?

Don said...

Greg,

Show me the errors. I don't care who laughed at it. The argument from authority doesn't move me.

Besides, in this post I am only reporting what Eaton, Konner and Shostak concluded. Cordain wasn't even part of it, by the way.

Show me data that African wild game has more fat than Ledger found.

The fat eaten by Eskimos is "animal" but it is very different from supermarket (quality and quantity) and even from domestic grass fed meat. It is marine oils predominantly. This makes the Eskimo experience a poor proxy for diets high in animal fat. The fat of the Eskimo diet just is not the same as "animal fat." Calling it "animal fat" grossly oversimplifies the fact.

Unlike some, I don't assume that all primitive diets produced the same health effects. Eskimos had problems not had by other tribes (hemorrhagic stroke, osteoporosis). Masai had atherosclerosis. Life expectancies differed. Weston Price noted different skeletal development from tribe to tribe in Africa, did not consider the Masai physique optimum compared to fish eating tribes.

When people moved out of Africa, we have no doubt that they experienced vitamin D deficiency (that drove selection for lighter skin pigmentation). So we know that when people left Africa, they encountered diseases due to a mismatch of the African constitution and the northern environment, including northern foods. Many of diet-related diseases would not kill you before you reproduced so there is no reason to believe that the underlying constitution would change despite the change in environment.

We know that different diets among modern people have very different health effects. I don't see how anyone can assume that the different diets of primitive groups had exactly the same good health outcomes. Wishful thinking, I would call that. We evolved in Africa, the exodus is a blip of time in the evolutionary scale.

Helen said...

Once again, I appreciate your focus on Africa. It makes so much sense.

Shel said...

"Virtually all of human evolution took place in Africa, so we can expect our baseline physiology to be more adapted to the diet available to our African ancestors, than to any human diet that emerged after the African exodus in northern environments"

yes, yes, yes!

this is what i've thought for a while now. but regardless of fat lost in firepit cooking, i think raw meat was probably eaten as regularly as cooked (out of convenience), thus all fat would be consumed at these times (i eat raw meat regularly, and once you get used to it, you really crave it).

...so i wonder if the fat intake may be a bit higher. also, Cordain, who has worked with Eaton, gave himself a headslap relatively recently for forgetting to include hunted and scavenged marrow and brains etc.

i wonder if this study included these extra fat sources.

...notwithstanding, i think you're correct about the free fat issue.

Don, maybe it's my bias, due to my past dietary experiments, but i really think you're making a breakthrough here. you're on fire. be prepared for pushback from the low-carb Paleo Peanut gallery. ;D

Steve Parker, M.D. said...

Here's a more recent scientific reference (one of the authors is Cordain):

Kuipers, R., Luxwolda, M., Janneke Dijck-Brouwer, D., Eaton, S., Crawford, M., Cordain, L., & Muskiet, F. (2010). Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet British Journal of Nutrition, 1-22 DOI: 10.1017/S0007114510002679.

Neonomide said...

Hi Don,

There seems to be at least 5 genes that non-african heritage Homo sapiens seem to have from Neanderthals, according to a new study:

http://www.mpg.de/617258/pressRelease20100430

Perhaps our "fat genes" differ too depenging on genetical make-up, since afro-american people seem to gain fat more easily on fatty diets. Any thoughts?

If proportional fat content of game rises when animals' size rises (especially in marine animals), we may assume that fat has been more important in the upper paleolithic, still?

By the way, Cordain et al. have argued that fishing was not that recent phenomenon - other watery creatures probably still were. I guess the evidence of fishing spears etc might be harder to find because of the wet environment's effects on wood too?

Just raising a few thoughts, keep on analyzing this stuff it's interesting. I personally cannot pass the "ketosis shift" too easily at all, especially when exercising a bit, so my paleo plan obviously has some 40-50% (good) carbs and I'm of course wondering if it's ok. Cordain's (2000) study got 22-40% carbs on average and it's interesting to analyze why Eaton seems to disagree.

As Stephan just pointed out in his blog, some of the most insulinogenic food seems to also be very satieting. This also seems interesting in the light of paleo theory.

Neonomide said...

Here's one study that links obesity to genetic differences between caucasian ja african heritage:

http://www.plosgenetics.org/article/info:doi%2F10.1371%2Fjournal.pgen.1000490


Differences in ability to process fat in carb rich environment, perhaps? Sure, there are umpteen factors at play and my thought of some genetic Neanderthal 'disruption' may or may not be there. But fatness/metabolic processes seems to have some racial biases.

Editing my former post: Aren't especially saturated fats proportionally richer in bigger land animals, overall? Not just fats - which would probably mean a more mono than fat, proportionally.

Don said...

Steven Parker,

I already blogged a bit about that study. Waiting for some info from one of the authors before continuing, but that study also did not estimate a high fat content of African paleo diet...it suggested 30-39% of calories from fat as a possibility.

Shel,

Thanks. Yes, this one did not estimate contributions of marrow and brain. The more recent one cited by Steven Parker did. Still did not come up with a high fat diet. Brain, tongue, and marrow aren't that large a part of African mammals. A rhino weighs 1000 kg, but brain is only 0.4 kg (0.88 lb). Split that 20 ways for a tribe you get 0.7 ounce serving per tribe member. Further, as I will discuss soon, African ancestors were NOT successful at hunting megafauna like rhinos. There is a large error built into the idea that humans evolved hunting large game. There is a very good reason to think that, prior to leaving Africa, humans were NOT successful at large game hunting.

Don said...

Greenacres,

Yes, it does. In fact, if you watch The Khalahari and Appalachian episodes of Bizzare Foods, Andrew Zimmern also discusses the taste of wild animal fats. In the Appalachian episode, he visits some native Americans who have bear meat. They explain that they don't eat the fat at all, and they boil the meat with a special method to remove the bad flavor.

Briefly, many wild animal fats don't taste that good, they in fact tend to be bitter. I have had a hunter friend tell me that he could not eat the fat of bears he has killed, it tastes too bitter, presumably from fat-soluble plant constituents from the bear's diet stored in the fat. We assume that wild animal fat was delicious. Try some yourself before deciding that hunters preferred any type of animal fat to any other food.

Don said...

Neonomide,

I haven't read Stephan's post, but I know of a number of papers that show that insulin is a strong stimulator of satiation center of the brain, and many also showing that carbohydrate is far more satiating than fat, on a calorie for calorie basis. Google "insulin and satiety." You will come up with several papers indicating that insulin is a satiety hormone. If so, then low carb could mean low satiety. YMMV.

el66k said...

Again,Don, where is the evidence that the Masai diet produces atherosclerosis. If it this "http://www.ncbi.nlm.nih.gov/pubmed/5007361", then I hope you have already read this "http://wholehealthsource.blogspot.com/2008/06/masai-and-atherosclerosis.html".

mem said...

Don,

You might find this of interest:

< Specifically, it suggests that lithics were used to process uncooked plant matter that was then cooked and later consumed by Neanderthals. Overall, the evidence therefore continues to indicate that Neanderthals not only ate plants, but also cooked them to both facilitate their consumption and increase their nutritiousness. >

http://averyremoteperiodindeed.blogspot.com/2011/05/raw-and-cooked-caveman-redux.html

Collins, M., & Copeland, L. (2011). Ancient starch: Cooked or just old? Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1103241108

Henry, A., Brooks, A., & Piperno, D. (2010). Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium) Proceedings of the National Academy of Sciences, 108 (2), 486-491 DOI: 10.1073/pnas.1016868108

Henry, A., Brooks, A., & Piperno, D. (2011). Reply to Collins and Copeland: Spontaneous gelatinization not supported by evidence Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1104199108

The idea that use of seal oil for lamps somehow significantly reduced the fat intake, at least for coastal bowhead whale hunting Inuits just doesn't fly in the face of the obvious. Whale eating and whaling were and are the center of the culture. Bowhead whales are HUGE and the raw and boiled fat/skin keep excellently frozen for very extended periods of time. When you eat the skin and fat, which is by far the largest portion of this HUGE sea mammal, the fat quite literally runs down your face! And the wild caribou that is hunted and eaten today certainly has plentiful, ovbious fat. I have cut up and portioned out lots of caribou killed within the previous 24-48 hours, as well as having eaten it as my only meat source for several months at a time.

Inland tribes who were not whale hunters would have had a somewhat lower fat diet that beluga or bowhead hunters. But I would still really question the idea of them having had a "lean" diet.

I am an avid reader of your blog and have learned a great deal from it. I appreciate your depth and breadth of experience and knowledge of nutrition, and the obvious passion you have for the subject.

Thank you!
mem

Alan said...

Don, your use of the term "protein poisoning" is sloppy.

The term does not google to any single definition. there's vegans out there citing China Study to show that we shouldn't eat meat because of "protein poisoning". Come on Don, you can do better than this.

There apparently are limits to our ability to de-nitrogen-ify proteins so that they can get metabolized as carbohydrates; but your usage of the term, is in the nature of what mathematicians and physicists call "handwaving".

Don said...

el66k,

According to the paper cited by Stephan:

"The old and the young Masai do have access to such processed staples as flour, sugar, confections and shortenings through the Indian dukas scattered about Masailand. These foods could carry the hypothetical agent."

Stephan then concludes that the long period of a high fat diet can't be the cause of Masai atherosclerosis. There is a big flaw in this reasoning: Simply, if flour, sugar, etc are the cause of the atherosclerosis, then it should appear in both the young and the old Masai...both before and after the dairy period. But in fact, their own data shows it occurring only in the men after their long period of a high fat dairy based diet. The data actually strongly suggests that it is the 20 years of eating a high dairy fat diet that causes the atherosclerosis to develop. Again, if it was due to the "sudden" switch to flour etc, we should find the same atherosclerosis in the Masai children under 20, who eat those foods and not the dairy-based diet.

Don said...

Mem,

Thanks for the references.

Re seal oil intake, all I said was that burning seal oil or whale blubber for fuel reduces the amount available for use as food (reduced the potential fat content of the diet). Obviously any oil you burn in lamps can't contribute to dietary fat intake. I didn't anywhere say or imply that the Inuit have a lean diet.

On top of that, Inuit are NOT Paleolithic people. They are post-paleolithic hunter-gatherers. Inuit are descendants of !Kung ancestors, as are all other modern humans. The diet of Paleolithic !Kung ancestors are the baseline for humanity in general, not Inuit.

Don said...

Alan,

Where in this post do you find the term "protein poisoning." I don't see it anywhere.

Anyway, if I used that term, I would of course be referring to the very well established fact that the human liver can only process so much ammonia in a day. Very high protein diets (>250g per day) can result in accumulation of ammonia in the blood....this is what I would mean by protein poisoning, wherever I used the term.

malpaz said...

OK, I tried to do an analysis…say you are tribe X and live near the water(tropical). You find a coconut tree full of coconuts. So you have an entire coconut to yourself for the day. You also find some wild fruit. Then, you fish and get entire fish(skin/bones) and you happen to find an egg. Analyzing this scenario…

Coconut
Fat Calories
135 g fat.
Calories From Protein
13 g protein.
Calories From Carbs
32 g carbs,.

1395 calories

A medium mango has
.5g fat
35 carbs
1g protein

130 calories

A small whole fish(say you eat 2)
Protein content 42
Fat content 8

120 calories

Bird egg
6g fat
9g protein

90 calories

In summary that comes out to 1873 calories, 72% fat 14% carb and 14% protein…. You don’t find much potato on islands IMO and a marshier area will equate to more fruit. Things like coconuts are storable. Fish and skin can be dried. I highly HIGHLY doubt the brain of any animal caught went to waste- HG I don’t think are that stupid. I have seen and eaten squirrel tail(a ruminant similar to a mongoose) which had a HIGHLY fatty tail, small brain but for its size the brain is big. I am sure we ate our fair share of fish like clams and mussels because if you see a sea otter in the wild, they use their ‘hands’ to crack shellfish and eat them so I am sure we caught on. I would like to think we were pretty smart from watching other animals. Maybe we didn’t value fish eggs like some think because we knew allowing the fish to birth meant more food. Regardless of what animal is caught, between brain, spleen, liver and stomach contents it is going to be fatty, not to mention have marrow. Now, again assuming HG are smart, I sure as hell would pass up this ‘use’ of any oil before I fed myself, and I sure as hell would have common sense to not cook off much fat from meat. I doubt there was much cooking of organs anyways.

I dunno, I have been pondering this and it just doesn’t make much common sense.

Don said...

Malpaz,

You seriously believe that someone presented with a whole tree full of ripe mangos would eat only one in a day? MOreover, on 'islands' like in the South Pacific, tubers are very common foods: taro, cassava, yucca, sweet potatoes. People also eat wetlands tubers like lily bulbs, lotus root, etc.

And on what "island" did humans evolve? AFRICA.

Plus, your example is lone feeder. Humans don't eat alone. Cooperative sharing of foods is one of the key characteristics of human culture and adaptation.

Swartkrans excavations suggest very strongly that human ancestors were using digging sticks to unearth tubers about 2 million years ago.

http://www.swartkrans.org/swartkrans-publications/

There are other physiological reasons to believe that common fats were not common foods in ancient diets. More in a later post.

Dustin C said...

Hi Don,
I know my personal observations can’t be directly applied to Paleolithic people by any means, but I think certain methods of preparing animals products without certain tools can still maintain plenty of fat from the animal. I spent nine weeks living among modern day nomads of Mongolia. I’m an extreme adventurist, and I do these things solo and fully submerging myself.
One thing they did was take the kidney fat (also blood, organs, and flour) and stuff them in the intestines. They took special care not to puncture the intestines to make sure the fat would not escape. Then it was cooked a variety of ways but over an open fire was often done.
Another thing was cooking the animal from the inside out. We did it with goats and marmots. I don’t feel like explaining the whole processes but the cliff note versions was that the animal was stuffed with hot rocks, sewn shut, and then left to cook. The fatty liquid broth accumulated inside the cooking animals was then was drank after words.
I would have the liver kidney sandwiches. But the twist, instead of bread it was fat wrapped around the organs pieces.
I even learned how to make vodka from milk.
I’m not necessarily disagreeing with you; I just don’t think we have all the information.

john said...

Don, Regarding the "preference" comment, I didn't claim any of those things you argued against. I was providing a point to counter the idea that just because animals are lean, people eat low fat.

Miki said...

Don
It so happens that I am working with Ledger 1968 paper for another purpose and come to an opposit conclusion.
Take Buffalo for example. Liveweight is 753 kgs, carcass fat is 5.6% of carcass weight (380 kgs) so 21.3 kgs. Offal fat is 1.2% of liveweight so 9kg. Add to this marrow fat (Bunn & Ezzo 1993:370) which Ledger didn't measure and you end up with 31.1 kg fat or 9000*31.1= 279,700 calories. In Ledger 1968:299 there is a table for protein content of the animal which gives a number of 49.8 kgs for Buffaloץ If you multiply by 4000 you end up with 199,200 calories. It means that 54% of the calories of the buffalo come from fat. Fat is normally given as % of liveweight and doesn't look that much (2-6%) for African animals but if you take away the bones and the water and take into account the relative caloric density of fat vs. protein the picture looks quite different.
The Paleolithic people hunted large game with a lot of fat. If they didn't lit candles with it theט must have consumed plenty of it.
I have many other remarks and will revert when I have more time.
Don't stop stirring the pot. We all learn from it.

Miki
Bunn, H. T., & Ezzo, J. A. (1993). Hunting and Scavenging by Plio-Pleistocene Hominids: Nutritional Constraints, Archaeological Patterns, and Behavioral Implications. Journal of Archaeological Science, 20(4), 365-398

Miki said...

a

CarbSane said...

Excellent Don!

I've been wondering about much the same thing for over a year now since The New Atkins authors cited Eaton as justification for a low carb diet. This seemed at odds with what I found when I read the Eaton paper.

And yet the LC and Paleo movements seem to be getting ever the more militarily high fat as the only "right way" to go.

Interestingly, Lindeberg is often cited when referring to the success of a Paleo diet. But the "Paleo diet" he used was at the high end of low carb (around 30%) and not particularly high fat (around 40%) and lower in saturated fat than the "diabetes diet" it was compared to.

mario_encinias said...

Well, you won't be excommunicated by me Don. I think what you're doing is refreshing and may lead to a much needed paradigm shift in the paleo community.

I find the high-fat-low-carb-paleo position in this debate suspect for two reasons. The first is that it not only failed me as a weight loss regimine (and I am very committed on these matters. I almost never deviate from paleo foods), but I became incredibly ill after gaining a lot of weight, even in spite of maintaining ketosis throughout. It was an incredibly frustrating experience especially since the insulin theory of fat regulation seemed so uncontraversal. This experience suggested confounders not easily explained by the low-carb theory.

But secondly, the out-of-Africa theory of human origins seems fairly obvious these days, especially after works stemming from the human genome project. And if writers like Chris Wilson are correct, the Kung of south east Africa boast the oldest known genotype on earth. Their diet may not be a perfect analogue for the diet of early humans but it is a pretty good candidate since they are from the same region, share the same genes, and are subject to the same ecological and economic constraints as our early ancestors. And their diet is precisely the type of diet you are advocating: high in tubers and seasonal produce, and low in large game. They delight in big kills and organ fat, but the rate of success for killing these animals is not only low, but is further constrained by compulsory meat sharing. The ethnographic accounts of Borshay Lee, the Marshall family, and others are particularly helpful on this point. Needless to say, a high saturated fat diet is not possible for these folks.

I also find it suspicious that nature would select for very strong cravings for animal fat, had this item not been scarce in our ancestral environment. Our cravings drive human food habits that were intended for an environment that was characterized by foods with "low reward properties" as Stephen Guyenet put it, and large game fat posseses high reward properties.

So for now, I'm throwing my lot in with Steffan Lindeberg, Loren Cordain,and bloggers like yourself. Keep on trucking Don. Its not easy smashing idols they way you're doing. We need it though. Take care. Mario

Don said...

Hi Phil,



Regarding my statement:

"Those saturated fats have to be safe in any quantity, or not safe at all..."

When I wrote this, I was referring to the attitudes of others...on the one hand, you have the high fat proponents, say the WAP group, who seem to think that saturated fats are safe in any quantity, and on the other, you have people who think saturated fats are not safe at all. Either of these positions violates the basic principle of toxicology, which is that the dose makes the poison. All the other statements are articulations of that principle...i.e. each of these fats are 'good' in the right amount, and toxic in excess. I don't see why saturated fats should be any different...

Regarding these two studies:

- Rose, et al. (1965): Replacing animal fat with corn oil for two years lowered serum cholesterol by 23 mg/dL but quadrupled cardiac and total mortality.
- Sydney Diet-Heart Study (1978): Replacing animal fat with vegetable fat for five years lowered cholesterol by five percent but increased total mortality by 50 percent."

These studies suffer from one glaring problem: They don't and can't show an effect of lowering animal fat consumption because they had two variables: 1) reducing animal fat, and 2) increasing vegetable fat. To see an effect of reducing saturated fats, you would have to only reduce saturated fats, not also add vegetable fats.

Outside of the highfatsphere, among the low fat thinkers, some point out that all these studies may involve baseline intakes of saturated fats that exceed a threshold for harm. Baseline intakes of fat in Europe and America might just be too high to detect a benefit of lowering the intake, i.e. both low and high consumers might be consuming an amount above the threshold for harmful effects. If (hypothetical, not based on any data) say 10 grams of saturated fat daily exceeds the threshold for adverse effects, and doubling that doesn't significantly increase the adverse effects, and Americans consume between 10 and 20 grams daily on average, there will be little detectible difference between high and low intakes. You might have to find a population that consumes on average less than 10 grams daily (i.e. below the threshold), say, for example, only 5 grams daily, to detect a positive effect of lower intake. Does that make sense?

Don said...

PaleoPhil,

"Why the focus on cooked tubers rather than roots and tubers which are edible raw?"

Simply because abundant historical and present data shows that people do very well on cooked starches, indicating that humans have very well adapted to cooked starches. If humans have been cooking starches for 1.5 million years (we have some evidence for this early date of control of fire at Koobi Fora) this represents 25% of all human evolutionary time since the last common ancestor of humans and great apes. We also have pretty strong anatomical evidence for adaptation to cooking, namely that we have very small teeth for body size compared to either raw vegetarian apes or carnivores. Dental reduction occurs in response to increased softness of food. In addition, as I discussed in my series on raw vegan diets, we absorb a greater proportion of the nutrients from cooked than from raw plant matter. In evolutionary times, this would have led to dramatically improved reproductive success, resulting in rapid selection for cooking and adaptations to cooked foods. In other words, we have pretty good reason to believe that humans are adapted to cooked foods, not raw.



I doubt that processing affects saturated fats significantly... their high melting points and lack of unsaturated carbons make them very resistant to damage by heat, light, or oxygen. However, I think someone should test the hypothesis anyway, just to rule it out, if indeed it can be ruled out.

Regarding your experience with venison suet:

I am sure that the flavor of the fat varies widely depending on what the animal ate. Animals like deer predominantly grazing on grasses and shrubs probably all have fat tasting similar to grass fed beef fat, which in my experience some (like me) but not all people like; but animals like bear, porcupine, and others that eat many other plants and some animals probably have much more widely variant fat flavor with bitter overtones from plant compounds.

BTW, I have met many people (not me) who say that they hate wild game, and grass fed meats, not liking the "gamey" flavor, which seems to argue against humans having had a significant adaptation to a wild game based diet--it seems unlikely that an animal adapted to a game-based diet would have many if any members who don't like the taste of wild game. I know that tastes change and are conditioned by experience, but if humans really had a game-BASED (as opposed to game-SUPPLEMENTED diet for millenia, I would expect that this would select for taste-buds that recognize the flavor of game meat as the best of flavors. Like 'umami.' I can't imagine any lion not liking wild antelope meat, even if it was raised initially on supermarket meats. Its life depends on liking meat, whether gamey or not. Just a suggestion,not completely thought out.

Don said...

Mario,

Thanks!

Gabriel said...

If rendered fat is not 'paleo' then neither are plants which have undergone drastic alteration due to selective breeding (which is most modern plants) and neither are modern animals who have been selectively bred. How much technology do you think it took to breed a wildebeest into a modern steer? We're talking generations upon generations of technological use to capture the animals, pen them, rope them, harness them, feed them. Rendering wild bear fat or the kidney fat from a winter elk takes much less technology than selective breeding does.

Your logic has holes.

selina.roesner said...

Well, GREAT post! I searched and wondered a long time why paleo should be high fat and low carb. I have to say that i tried it all.

Some weeks ago, i was on Sisson's Primal diet. I thought it would be right and "fat gain shouldn't be an issue at all" (Sissons statement), but this statement failed! I think i gained 10 pounds in 10 weeks, although i trained hard.
Well, okay, some people succeeded with it.

Also i found that high fat meals really felt like rocks in my stomach.

I live in Germany and i follow posts from German "fitness guru" called Ulrich Strunz (www.strunz.com). He's a MD. He makes blood tests (with his patients) and gives them supplements when something is missing.

What he found is, when people have all the ESSENTIAL things (vitamins/minerals, amino acids, ESSENTIAL fatty acids) in their blood, they feel great. More than that, he actually HEALS nearly everything with it!

So regarding this, it's obvious what is needed to have a perfect health: vitamins/minerals/amino acids/omega3 (because he states that we get enough of o6 anyway).

I really trust this guy, because he does this everyday and has great results with it.

So let's face it. When it comes to perfect health, all you need is to watch for the ESSENTIAL things.

What does this guy recommend?
When he studies the blood of his patients, he recognizes that you need approx. 30-35% protein in your diet. He actually recommends a high vegetable (and fruit diet), along with 5-7g of O-3FA.
When he want his patients to lose weight, he gives them the advice to practice a low carb diet (but it's more a protein sparing modified fast with some vegetable).

What I want to add is: We know that you can turn artheriosclerosis back into normal (Ornish!). What we also know is that Japanese don't get heart attacks. And, as mentioned in the post, Massai on a high fat diet do have atheriosclerosis (though without heart attacks), the Inuit, too.

Where did we evolve? I guess in the jungle, over millions of years. We went to Europe, Asia and so on, just a few ten thousand years ago.
A famous theory says that our brain did not grow that big because of the energy we got with high fat and high protein diet. It was because of DHA. There are studies with small animals (or insects or so), give them DHA, their brain grow even in one generation!!
This theory also suggests that we evolve near to lakes or sea, where seafood is abundant.

Last question is: What can you eat in the jungle? Well, Don actually posted that - "fruit article".


best regards from Germany
Chris

selina.roesner said...

What I forgot. When it comes to perfect health, the best results do you get with calorie restriction. Well, you do not have to do a restriction of 40%. When you follow a diet high in protein, high in fruit and vegetable, lower in fat (with high o3) you will actually be lower in your calories and therefore you will have a better health.
The high fat diet is just a try to mimic a "low insulin" situation. Why not just stop eating? Skip breakfast, skip lunch...

lightcan said...

Hi Don,

Does this mean that you're changing your macro recommendations? The last time you posted the breakdown of your meal last year it had 60% fat in it and for weight loss you recommended 90 grams of fat with 50-80 grams of carbs and protein respectively, which at maximum could be seen as almost 50%. Should I reduce the fat accordingly?
Thanks.

Don said...

Lightcan,

I am changing my recommendations. For fat loss especially, I think low fat with adequate EFAs is best, i.e. less than 30% of calories as fat.

Miki said...

Don
I have no idea what is the optimal fat percentage but I have few further remarks regarding your post.
1) Both Eaton and Kuipers do not actually base themselves on archeological or any other observation. They are both intellectual exercises of the "what if" type so I would place too much importance to their conclusions.
2. One of the best and may be the only way for a good estimation of plant based food in the paleolithic is N isotope analysis. For a good discussion of the archeological evidence from N isotope analysis I would refer you to three papers by Richards which are listed at the end of this post. The three of them support a very high animal sourced component of the diet in the period leading to the agricultural revolution.
3. A new paper by two very respected paleoanthropologists (Roebroeks & villa 2011)present a convincing case for no habitual use of fire prior to 400 kya.
4. Regarding hunter gatherers diets I suggest that you take a look at Kaplan (2000:166) where diet of HG groups that were methodologically collected (there are not many of these) show a low component of plant in the diet. High plant component it only found in groups that have access to high fat plant food like mongongo nuts, Baubab seeds and Palm oil. Excluding these groups one arrives at a meager 17% plant component of the diet.
Thank you for providing an opportunity to discuss these issues.


Richards, M. P. (2002). A brief review of the archaeological evidence for Palaeolithic and Neolithic subsistence. European Journal of Clinical Nutrition,56(12), 16 p following 1262. Nature Publishing Group.

Richards, M. P-., & Trinkaus, E. (2009). Isotopic evidence for the diets of European Neanderthals and early modern humans. Proceedings of the National Academy of Sciences, 106(38), 16034-16039. National Academy of Sciences.

Richards, M. P. (2009). Stable Isotope Evidence for European Upper Paleolithic Human Diets. In J.-J. Hublin & M. P. Richards (Eds.), The Evolution of Hominin Diets Integrating Approaches to the Study of Palaeolithic Subsistence (pp. 251-257).

Kaplan, H., Hill, K., Lancaster, J., Hurtado, A. M., 2000. A theory of human life history evolution: diet, intelligence, and longevity. Evol. Anthropol. 9(4):156–185.

Roebroeks W. (2011), On the earliest evidence for habitual use of fire in Europe, pnas

Michal said...

Don said:

"I prefer having an income of $1 million per month. Does that mean that I always have what I want? Of course not.

[...]

People prefer a lot of things, that doesn't mean that they always have what they prefer. Hunters always wanted more fat than they could get."

Have you read Gregory Clark's work? It shows that majority of current humans are descendant from RICH minoroties of the past. It happens as fast as in historical times, by his own words ~90% population of England in 1800 is decendant of ~10% of rich people from the Middle Ages.

We don't have such data from the Paleolithic, but it's intuitively safe to extrapolate this. At least for men - from the genetics we know that humans are descendant from half as many men as women!

So when we look at our distant lineages we see few average or poor farmers or hunter-gaterers, instead we descent from RICH ones. What was the major difference between diets of rich and poor in the past? You guessed it - rich were eating much more meat and fat! Winners diet.

Today Bushmen, Pygmies are not from such lienages. They are loosers pushed out to very bad habitats by agricultural Blacks, and are shrunk compared to their predecessors. Eg. the known paleolithic relative to Bushmen is Boskop: a large man with a very large brain.

Curtis said...

This logic assumes that we ate the complete animal. What if we only ate the organ meat/fatty parts and not the muscle meat?

Theory: Human tribes would chase animals until they collapsed from exhaustion. Then, a feast starting with the organ meat, bone marrow, etc. would begin. After everyone gorged on these parts, much of the muscle meat would spoil and go to waste.

Doesn't it make sense to compare against other mammals than extrapolate percentages based on the fat composition of animals we likely ate?

http://www.ncbi.nlm.nih.gov/pubmed/9311957?dopt=AbstractPlus
"The macronutrient profile of this diet would be as follows: 2.5% energy as fat, 24.3% protein, 15.8% available carbohydrate, with potentially 57.3% of metabolizable energy from short-chain fatty acids (SCFA) derived from colonic fermentation of fiber."

We don't have the colons for fermentation though so instead maintained a high-fat diet by eating the high-fat parts of the animals we hunted.

On the more carnivorous side of the spectrum, the Iditarod dogs, do best on a high-fat diet.
http://www.helium.com/items/1341513-what-do-sled-dogs-eat

If both carnivorous and herbivore mammals tend to eat high-fat diets, why wouldn't we?

Paleo Phil said...

Don wrote: "When I wrote this, I was referring to the attitudes of others..."

OK, thanks for the explanation.

Don: "each of these fats are 'good' in the right amount, and toxic in excess. I don't see why saturated fats should be any different..."

I agree, theoretically speaking.

Don: "These two studies suffer from one problem: replacing animal fat with refined vegetable fat."

I suppose you'd have to replace the saturated fat with a food that everyone agrees is neutral, which seems difficult, or do multiple tests, substituting different foods, yes?

Don wrote: "Outside of the paleosphere, among the low fat thinkers, some point out that all these studies may involve baseline intakes of saturated fats that exceed a threshold for harm. ... You might have to find a population that consumes on average less than 10 grams daily (i.e. below the threshold) to detect a positive effect of lower intake. Does that make sense?"

Yes, is there any known population that is known to have eaten less than 10 grams of SFA/day?

I wrote: "Why wouldn't roots and tubers which are edible raw be even more optimal than those which require cooking?"

Don: "Simply because abundant historical and present data shows that people do very well on cooked starches, indicating that humans have very well adapted to cooked starches."

Many people, yes (though not me for whatever reason and I wish otherwise, but I may be an outlier, though others have reported faring poorly on cooked tubers and Robb Wolf has reported only being able to tolerate a certain amount), that's why I specified "*more* optimal", rather than just "optimal." As well as they do on starches that require cooking, isn't it possible they might do even better on cooked starches that are edible raw?

Doesn't the requirement of cooking suggest that these foods are at least a little less optimal than those that don't require cooking? Doesn't the consumption of raw tubers by both chimpanzees and African hunter gatherers suggest that raw tubers were consumed before cooked tubers and that humans might be even better adapted to tubers that are edible raw? Isn't it possible that starches which require cooking are consumed in addition to or instead of starches that are edible raw for reasons beyond health, like palatability, convenience, cost, and availability?

Don: We also have pretty strong anatomical evidence for adaptation to cooking, namely that we have very small teeth for body size compared to either raw vegetarian apes or carnivores.

Are those changes necessarily 100% beneficial, or could there be an element of physical degeneration? After all, smaller teeth and jaws aren't normally regarded as an advantage in the wild, are they? When people's jaws get smaller from eating grains, Weston Price and others call it physical degeneration, though in that case there is the element of teeth crowding that I haven't heard of from cooked tubers. Brain size did increase, but perhaps that could have been due to something other than cooking? Could it be a mix of adaptation and degeneration? It still seems like an open question.

Paleo Phil said...

Don: In addition, as I discussed in my series on raw vegan diets, we absorb a greater proportion of the nutrients from cooked than from raw plant matter. In evolutionary times, this would have led to dramatically improved reproductive success, resulting in rapid selection for cooking and adaptations to cooked foods. In other words, we have pretty good reason to believe that humans are adapted to cooked foods, not raw.

Given that our ancestors were not vegans I would be careful about drawing conclusions based on raw vegan diets. Are you suggesting that we humans have lost our adaptation to raw foods (in effect, that we have become what one scientist has termed "cocktivores"), so that even foods that are edible raw are better cooked? Even if that's the case, wouldn't a cooked tuber or root that is edible raw be better digested than a cooked tuber or root that is not edible raw? Has this been tested?

Even if higher calories from a cooked diet provided evolutionary and/or reproductive advantages, isn't it still possible that a raw or mostly raw diet that includes animal foods might offer health benefits to middle-aged and older people? When reproductive success is improved via agriculture and industrial processing, it's considered a bad sign. When it happens due to cooking, it's assumed to be a good thing. Why the seeming double standard? Isn't it possible that it could be like agriculture and other forms of processing--a sign of a bad thing?

Don: "I doubt that processing affects saturated fats significantly... their high melting points and lack of unsaturated carbons make them very resistant to damage by heat, light, or oxygen. However, I think someone should test the hypothesis anyway, just to rule it out, if indeed it can be ruled out."

Yes, I would have been skeptical of much difference myself years ago, but since I started consuming most of my animal foods raw, I've noticed that I experience mildly negative effects like stomach gas from fats heated above a very low temperature, with more gas the higher the fats are cooked. I used to consider such gas completely "normal," but now I wonder if it might be suboptimal. It's not scientific evidence, of course, and it's not an earth-shattering difference, but it does leave me curious. Stephan G. also mentioned that he gets stomach gas from crockpot-cooked bone broths, IIRC (as do I), and Danny Roddy reported getting it from pemmican (again, same here). I would be curious to see if they experienced less gas and felt any differently when eating their fats raw or heated at still lower temps or for shorter durations, in addition to checking for any differences in data like blood pressure, blood lipids, etc.

It seems like even some SFA proponents would agree that deep-fat frying in SFA at high temps would not be wise. Dr. Eades even sells a sous vide cooker that uses a low-slow cooking method. If we are truly completely adapted to cooking, why would sous vide be better than higher-heat forms of cooking? Perhaps there's a continuum of negative effects that includes small negative effects even at the lower levels of cooking and more negative effects the higher the cooking temperatures and times?

Don: BTW, I have met many people who say that they hate wild game, and its "gamey" flavor, which seems to argue against humans having had a wild game based diet--it seems unlikely that an animal adapted to a game-based diet would have many if any members who don't like the taste of wild game.

I was one, but I think this may be a matter of acclimation, as I now prefer the gamey flavor of some meats, though some, like raw lamb, are still too gamey for me.

Razwell said...

There was no one Paleolithic diet. We must never talk with certitude about nutrition. Too little is yet known to science. A CREDIBLE nutritional source ALWAYS admits to uncertainty and vast unknowns.

lizlamirp said...

I don't believe kangaroos should be included in the list of low-fat animals. They are endemic to Australia.

Fabulous food for thought, Don, your recent blogs have turned me in a whole new direction of enquiry when it comes to diet.

JW said...

I'd like to point out a couple of studies:

Saturated fat, carbohydrate, and cardiovascular disease

www.ajcn.org

A focus of dietary recommendations for cardiovascular disease (CVD) prevention and treatment has been a reduction in saturated fat intake, primarily as a means of lowering LDL-cholesterol concentrations. However, the evidence that supports a reduction in saturated fat intake must be evaluated in the context of replacement by other macronutrients. Clinical trials that replaced saturated fat with polyunsaturated fat have generally shown a reduction in CVD events, although several studies showed no effects. An independent association of saturated fat intake with CVD risk has not been consistently shown in prospective epidemiologic studies, although some have provided evidence of an increased risk in young individuals and in women. Replacement of saturated fat by polyunsaturated or monounsaturated fat lowers both LDL and HDL cholesterol. However, replacement with a higher carbohydrate intake, particularly refined carbohydrate, can exacerbate the atherogenic dyslipidemia associated with insulin resistance and obesity that includes increased triglycerides, small LDL particles, and reduced HDL cholesterol. In summary, although substitution of dietary polyunsaturated fat for saturated fat has been shown to lower CVD risk, there are few epidemiologic or clinical trial data to support a benefit of replacing saturated fat with carbohydrate. Furthermore, particularly given the differential effects of dietary saturated fats and carbohydrates on concentrations of larger and smaller LDL particles, respectively, dietary efforts to improve the increasing burden of CVD risk associated with atherogenic dyslipidemia should primarily emphasize the limitation of refined carbohydrate intakes and a reduction in excess adiposity.

Saturated Fat and Health: Recent Advances in Research

www.ncpi.nlm.nih.gov

Other work presented in this issue shows that a diet high in saturated fat has very different effects in the presence of carbohydrates than in their absence. A low carbohydrate diet that is high in saturated may actually lead to a reduction in plasma saturated fat compared to one that is also high in carbohydrate, a consequence of reduction of triglycerides in the low carbohydrate diet and persistent de novo fatty acid synthesis in the high carbohydrate diet.

Bryan Clark said...

Would you eat a raw vegetable that had more beneficial dietary content than the average vegetable (with no dietary disadvantages), but was not around during Paleo Man's diet (evolved within the last few thousand years)? How is that different from other, now available options (such as oils)? As I see it, the point is to choose your diet based on benefits (what our bodies require, based on genetics and evolution), not based on what was or was not available. Adhering to a set of rules that precludes eating beneficial things simply because they didn't exist seems silly to me. I'm willing to listen, however, if you can make some sense of it.

Think! said...

Quote: "The old and the young Masai do have access to such processed staples as flour, sugar, confections and shortenings through the Indian dukas scattered about Masailand. These foods could carry the hypothetical agent."

Stephan then concludes that the long period of a high fat diet can't be the cause of Masai atherosclerosis. There is a big flaw in this reasoning: Simply, if flour, sugar, etc are the cause of the atherosclerosis, then it should appear in both the young and the old Masai...both before and after the dairy period. But in fact, their own data shows it occurring only in the men after their long period of a high fat dairy based diet. The data actually strongly suggests that it is the 20 years of eating a high dairy fat diet that causes the atherosclerosis to develop. Again, if it was due to the "sudden" switch to flour etc, we should find the same atherosclerosis in the Masai children under 20, who eat those foods and not the dairy-based diet. (End quote)

What is the health staus of the older men who have grown up on the refined carb diets. Without knowing a few more variables I don't think we can necessarily conclude too much....