I got a post from Staffan Lindeberg about an articel in American Journal
of Clinical Nutrition by Loren Cordain, Boyd Eaton and others.
The first link did not work for me, the second requires subscription.

- Hans

http://www.ncbi.nlm.nih.gov/cgi-bin/Entrez/referer?
http://www.ajcn.org/cgi/content/full/71/3/682

Abstract:
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).