Krusty wrote:

> "Dana Carpender" > wrote
>
>>Cite?
>
>
> Eaton suggests that early primate diet was roughly 95% "plant foods". (see
> associated citations)

Dunno who Eaton is, but he
>
>

The paradoxical nature of hunter-gatherer diets: meat-based, yet
non-atherogenic.

Cordain L, Eaton SB, Miller JB, Mann N, Hill K.

Department of Health and Exercise Science, Colorado State University,
Fort Collins, Colorado, USA.

OBJECTIVE: Field studies of twentieth century hunter-gathers (HG) showed
them to be generally free of the signs and symptoms of cardiovascular
disease (CVD). Consequently, the characterization of HG diets may have
important implications in designing therapeutic diets that reduce the
risk for CVD in Westernized societies. Based upon limited ethnographic
data (n=58 HG societies) and a single quantitative dietary study, it has
been commonly inferred that gathered plant foods provided the dominant
energy source in HG diets. METHOD AND RESULTS: In this review we have
analyzed the 13 known quantitative dietary studies of HG and demonstrate
that animal food actually provided the dominant (65%) energy source,
while gathered plant foods comprised the remainder (35%). This data is
consistent with a more recent, comprehensive review of the entire
ethnographic data (n=229 HG societies) that showed the mean subsistence
dependence upon gathered plant foods was 32%, whereas it was 68% for
animal foods. Other evidence, including isotopic analyses of Paleolithic
hominid collagen tissue, reductions in hominid gut size, low activity
levels of certain enzymes, and optimal foraging data all point toward a
long history of meat-based diets in our species. Because increasing meat
consumption in Western diets is frequently associated with increased
risk for CVD mortality, it is seemingly paradoxical that HG societies,
who consume the majority of their energy from animal food, have been
shown to be relatively free of the signs and symptoms of CVD.
CONCLUSION: The high reliance upon animal-based foods would not have
necessarily elicited unfavorable blood lipid profiles because of the
hypolipidemic effects of high dietary protein (19-35% energy) and the
relatively low level of dietary carbohydrate (22-40% energy). Although
fat intake (28-58% energy) would have been similar to or higher than
that found in Western diets, it is likely that important qualitative
differences in fat intake, including relatively high levels of MUFA and
PUFA and a lower omega-6/omega-3 fatty acid ratio, would have served to
inhibit the development of CVD. Other dietary characteristics including
high intakes of antioxidants, fiber, vitamins and phytochemicals along
with a low salt intake may have operated synergistically with lifestyle
characteristics (more exercise, less stress and no smoking) to further
deter the development of CVD.

Dietary lean red meat and human evolution.

Mann N.

Department of Food Science, RMIT University, Melbourne, VIC, Australia.


Scientific evidence is accumulating that meat itself is not a risk
factor for Western lifestyle diseases such as cardiovascular disease,
but rather the risk stems from the excessive fat and particularly
saturated fat associated with the meat of modern domesticated animals.
In our own studies, we have shown evidence that diets high in lean red
meat can actually lower plasma cholesterol, contribute significantly to
tissue omega-3 fatty acid and provide a good source of iron, zinc and
vitamin B12. A study of human and pre-human diet history shows that for
a period of at least 2 million years the human ancestral line had been
consuming increasing quantities of meat. During that time, evolutionary
selection was in action, adapting our genetic make up and hence our
physiological features to a diet high in lean meat. This meat was wild
game meat, low in total and saturated fat and relatively rich in
polyunsaturated fatty acids (PUFA). The evidence presented in this
review looks at various lines of study which indicate the reliance on
meat intake as a major energy source by pre-agricultural humans. The
distinct fields briefly reviewed include: fossil isotope studies, human
gut morphology, human encephalisation and energy requirements, optimal
foraging theory, insulin resistance and studies on hunter-gatherer
societies. In conclusion, lean meat is a healthy and beneficial
component of any well-balanced diet as long as it is fat trimmed and
consumed as part of a varied diet.



Plant-animal subsistence ratios and macronutrient energy estimations in
worldwide hunter-gatherer diets.

Cordain L, Miller JB, Eaton SB, Mann N, Holt SH, Speth JD.

Department of Health and Exercise Science, Colorado State University,
Fort Collins, CO 80523, USA.

Both anthropologists and nutritionists have long recognized that the
diets of modern-day hunter-gatherers may represent a reference standard
for modern human nutrition and a model for defense against certain
diseases of affluence. Because the hunter-gatherer way of life is now
probably extinct in its purely un-Westernized form, nutritionists and
anthropologists must rely on indirect procedures to reconstruct the
traditional diet of preagricultural humans. In this analysis, we
incorporate the most recent ethnographic compilation of plant-to-animal
economic subsistence patterns of hunter-gatherers to estimate likely
dietary macronutrient intakes (% of energy) for environmentally diverse
hunter-gatherer populations. Furthermore, we show how differences in the
percentage of body fat in prey animals would alter protein intakes in
hunter-gatherers and how a maximal protein ceiling influences the
selection of other macronutrients. Our analysis showed that whenever and
wherever it was ecologically possible, hunter-gatherers consumed high
amounts (45-65% of energy) of animal food. Most (73%) of the worldwide
hunter-gatherer societies derived >50% (> or =56-65% of energy) of their
subsistence from animal foods, whereas only 14% of these societies
derived >50% (> or =56-65% of energy) of their subsistence from gathered
plant foods. This high reliance on animal-based foods coupled with the
relatively low carbohydrate content of wild plant foods produces
universally characteristic macronutrient consumption ratios in which
protein is elevated (19-35% of energy) at the expense of carbohydrates
(22-40% of energy).