The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)

Accounting for nutrient composition in human foraging decisions


1Plant Foods in Hominin Dietary Ecology Research Group, Max Planck Institute for Evolutionary Anthropology, 2Department of Anthropology, University of Utah

March 27, 2015 3:30, Grand Ballroom A/B Add to calendar

We report on the caloric content and macronutrient composition of foraged foods in the Twe diet. The Twe are an understudied population of forager-horticulturalists in Northwest Namibia who regularly collect a range of plant foods. We combine observational foraging data with data on energy expenditure and nutritional analysis to understand the motivations underpinning Twe foraging decisions. Consistent with traditional behavioral ecology models, we find that calorie-based diet rankings explain many Twe foraging decisions. However, recent government programs provide an abundance of carbohydrate rich maize meal, and we expect that Twe foraging is biased towards foods that improve their dietary macronutrient balance.

Lessons drawn from hunter-gatherer diets feature in popular hypotheses about the evolution of human diets and health. Many foraging models assume that calorie acquisition is the ultimate goal, but the use of calories in understanding foraging behavior has received criticism as we begin to understand how dietary macro- and micro-nutrient ratios affect health. However, very few studies actually report on the composition of foraged foods, even among well studied groups. This study works towards a more nuanced understanding of human foraging decisions, and explores the ways in which understanding the economic decision making process of modern foragers can inform our understanding of diet in the past.