Meat in the human diet: An anthropological perspective

Human ancestral diets changed substantially approximately four to five million years ago with major climatic changes creating open grassland environments. We developed a larger brain balanced by a smaller, simpler gastrointestinal tract requiring higher-quality foods based around meat protein and fat. Anthropological evidence from cranio-dental features and fossil stable isotope analysis indicates a growing reliance on meat consumption during human evolution. Study of hunter-gatherer societies in recent times shows an extreme reliance on hunted and fished animal foods for survival. Optimal foraging theory shows that wild plant foods in general give an inadequate energy return for survival, whereas the top-ranking food items for energy return are large hunted animals. Numerous evolutionary adaptations in humans indicate high reliance on meat consumption, including poor taurine production, lack of ability to chain elongate plant fatty acids and the co-evolution of parasites related to dietary meat.