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Welcome all seeking refuge from low carb dogma!

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Thursday, March 18, 2010

Was our ancestral diet REALLY VLC and high fat?


Awareness of the ancestral human diet might advance traditional nutrition science. The human genome has hardly changed since the emergence of behaviourally-modern humans in East Africa 100–50 · 103 years ago; genetically, man remains adapted for the foods consumed then. The best available estimates suggest that those ancestors obtained about 35% of their dietary energy from fats, 35% from carbohydrates and 30% from protein. Saturated fats contributed approximately 7.5% total energy and harmful trans-fatty acids contributed negligible amounts. Polyunsaturated fat intake was high, with n-6:n-3 approaching 2:1 (v. 10:1 today). Cholesterol consumption was substantial, perhaps 480 mg/d. Carbohydrate came from uncultivated fruits and vegetables, approximately 50% energy intake as compared with the present level of 16% energy intake for Americans. High fruit and vegetable intake and minimal grain and dairy consumption made ancestral diets base-yielding, unlike today’s acid-producing pattern. Honey comprised 2–3% energy intake as compared with the 15% added sugars contribute currently. Fibre consumption was high, perhaps 100 g/d, but phytate content was minimal. Vitamin, mineral and (probably) phytochemical intake was typically 1.5 to eight times that of today except for that of Na, generally <1000 mg/d, i.e. much less than that of K. The field of nutrition science suffers from the absence of a unifying hypothesis on which to build a dietary strategy for prevention; there is no Kuhnian paradigm, which some researchers believe to be a prerequisite for progress in any scientific discipline. An understanding of human evolutionary experience and its relevance to contemporary nutritional requirements may address this critical deficiency.
A few things jump out at me:
  • The diet is roughly isocaloric for the macronutrients.
  • The dietary villain du jour --  fructose -- is well represented in fruits and honey.  Could that be why we actually have a specific enzyme for processing this nutrient? 
  • Fiber intake is huge!!
  • Fat intake is almost "low fat" levels.
I see no reason to discount the assertions in this article regarding tracing the modern human genome to Stone Age man living in NE Africa.   The meat eaters often point to the Inuit as "proof" of the ancestral value of high fat intake.   But I'm not an Inuit descendent, nor am I living in a super cold climate.  Also, those cold water fishes and seals have a fat content that in no way resembles the fat of today's farm animals -- even the grass fed variety.  

Many in the LC community point to Paleo diets to counter claims that meats are bad for us etc.  Fair and correct in general.  But many of those also consume a LOT of dairy fats -- something Paleo-Dude and Dudette had little or no access to.  IF they had access to dairy, it seems far more likely they would just drink it carbs and all.   Many also eat only the high fat cuts of meat (cooked with more fat).  Paleos ate the whole bird (including the shunned chicken breast), not just chicken wings. 

I'm not willing to give up my dairy entirely, but I take away from this to forgo the cheese over the nuts and strive to eat the whole of the whole foods.  That may not be possible, but to try to balance that prime rib with chicken breast and the like.

4 comments:

Juliana said...

Are you sure the fat intake was almost at "low fat levels?"

It is so funny how one author refutes another!

Taubes says that according to anthropologists, our ancestors preferred the meat that had the higher amount of fat, which also happens to lions.. And why are they not fat?

carbsane said...

Hi there Juliana, From GCBC:

This interpretation, shared by Rose, was established authoritatively in 1985, the year after the NIH Consensus Conference, when The New England Journal of Medicine published a quantitative analysis of hunter-gatherer diets by two investigators— Boyd Eaton, a physician with an amateur interest in anthropology, and Melvin Konner, an anthropologist who had recently earned his medical degree. Eaton and Konner analyzed the diets of hunter-gatherer populations that had survived into the twentieth century and concluded that we are, indeed,genetically adapted to eat diets of 20– 25 percent fat, most of which would in the past have been unsaturated. Eaton and Konner’s article has since been invoked to support low-fat recommendations— in Diet and Health, for instance— as Rose’s argument suggests it should.

But Eaton and Konner “made a mistake,” as Eaton himself later said. This was only corrected in 2000, when Eaton, working now with John Speth and Loren Cordain, published a revised analysis of hunter-gatherer diets. This new analysis took into account, as Eaton and Konner’s hadn’t, the observation that hunter-gatherers consumed the entire carcass of an animal, not just the muscle meat, and preferentially consumed the fattest parts of the carcass— including organs, tongue, and marrow— and the fattest animals.

Reversing the earlier conclusion, Eaton, Speth, and Cordain now suggested that Paleolithic diets were extremely high in protein (19– 35 percent of calories), low in carbohydrates “by normal Western standards” (22– 40 percent of energy), and comparable or higher in fat (28– 58 percent of energy). Eaton and his new collaborators stated with certainty that those relatively modern foods that today constitute more than 60 percent of all calories in the typical American diet— cereal grains, dairy products, beverages, vegetable oils and dressings, and sugar and candy—“ would have contributed virtually none of the energy in the typical hunter-gatherer diet.” This latest analysis makes it seem that what Rose and the public-health authorities considered biological normality in 1985— a relatively low-fat diet— would now have to be be percent of energy). Eaton and his new collaborators stated with certainty that those relatively modern foods that today constitute more than 60 percent of all calories in the typical American diet— cereal grains, dairy products, beverages, vegetable oils and dressings, and sugar and candy—“ would have contributed virtually none of the energy in the typical hunter-gatherer diet.” This latest analysis makes it seem that what Rose and the public-health authorities considered biological normality in 1985— a relatively low-fat diet— would now have to be be considered abnormal.* 22 (see note below)

Taubes, Gary (2007-09-25). Good Calories, Bad Calories (Kindle Locations 1682-1698). Knopf Doubleday Publishing Group. Kindle Edition.
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Note 22: Melvin Konner has doubts about the conclusions. “Boyd and I probably did underestimate the amount of meat in the Paleolithic diet based on our extrapolations for hunter-gatherers,” he said. “I just don’t think it’s nearly as extreme as this paper claims.”

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Here's the link to my quick blog post highlighting the update http://carbsanity.blogspot.com/2010/05/paleolithic-nutrition-eaton-12-yr.html which cited this paper: http://www.direct-ms.org/pdf/EvolutionPaleolithic/Eaton%20Paleo%20Nutri%20Review%20EJCN.pdf

>>>>>>> goes and searches her Kindle copy of GCBC for citation of the 1997 Eatons and Konner peer review update. Does not find. Gee ... I wonder why that might be. Table below is from that paper.

Yes, it is so funny how one author refutes another when the other is so adept at cherry picking references and often misrepresenting those that he does.

carbsane said...

Taubes somewhat misrepresented what various anthropologists say about ancestral diets in GCBC (why am I not surprised).


The 2010 fat recommendations of Eaton and Konner were increased to a range from 20-35% fat (and still low sat fat) which will be clear in an upcoming post. I'll probably do a blog post on Taubes and his representations of the paleo diet at some point as well.


Lions are carnivores, humans are not so there is no relevance there.

Juliana said...

I am waiting for your post.

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