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

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).

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

“…When the two polar hunter-gatherer populations, who have no choice but to eat animal food because of the inaccessibility of plant foods, are excluded from Table 1, the mean score for animal subsistence is 59% and that for plant food subsistence is 41%. These animal to plant subsistence values fall within the same respective class intervals (56 -65% for animal food; 36 -45% for plant food) as those we estimated from the ethnographic data when the confounding influence of latitude was eliminated (Cordain et al, 2000a). Consequently, there is remarkably close agreement between the quantitative data in Table 1 and the ethnographic data.…”

“…Because smaller animal species have less body fat than larger species, their carcasses contain relatively more protein as a percentage of their available food energy (Figure 3). The nature of this relationship is virtually identical among all vertebrates (Cordain et al, 2000a) and is exemplified by the cubic polynomial equation in Figure 4. Hunter-gatherers tended to shun very small animals or fat-depleted animals because of their excessive protein content (Noli & Avery, 1988;Speth & Spielmann, 1983;Speth, 1989), and numerous historical and ethnographic accounts have documented the adverse health effects that have occurred when people were forced to rely solely upon the fat depleted lean meat of wild animals (Speth & Spielmann, 1983).…”

“…However, based upon a single quantitative dietary study of hunter-gatherers in Africa (Lee, 1968) and a compilation of limited ethnographic studies of huntergatherers (Lee, 1968), many anthropologists and others inferred that, with few exceptions, a near-universal pattern of subsistence prevailed in which gathered plant foods would have formed the majority ( > 50%) of food energy consumed (Beckerman, 2000;Dahlberg, 1981;Eaton & Konner, 1985;Lee, 1968;Milton, 2000;Nestle, 1999;Zihlman, 1981). More recent, comprehensive ethnographic compilations of hunter-gatherer diets (Cordain et al, 2000a), as well as quantitative dietary analyses in multiple foraging populations (Kaplan et al, 2000;, have been unable to confirm the inferences of these earlier studies, and in fact have demonstrated that animal foods actually comprised the majority of energy in the typical hunter-gatherer diet.…”

“…Our analyses of both the ethnographic data (Cordain et al, 2000a) and the quantitative dietary data (Table 1) show that, even when plant food sources would have been available year round at lower latitudes, animal foods would have been the preferred energy source for the majority of worldwide hunter-gatherers. Only when it was ecologically difficult to procure animal food sources, and=or when energy-rich and easily obtainable plant foods such as the mongongo nut (in the case of the !Kung people studied by Lee, 1968) were available, did plant foods prevail in hunter-gatherer diets.…”

“…In a likewise manner, varying amounts of body fat also exclusively determine the relative protein to fat energy ratio in an edible carcass (Cordain et al, 2000a). Because smaller animal species have less body fat than larger species, their carcasses contain relatively more protein as a percentage of their available food energy (Figure 3).…”