Metabolic Challenges of the Modern World: Evolution and Human Nutritional Health

Friday, February 15, 2013
Room 302 (Hynes Convention Center)
William Leonard , Northwestern University, Evanston, IL
Over the last 25 years, evolutionary perspectives on human dietary consumption and nutritional health have received ever greater attention among both anthropologists and nutritional scientists. This presentation  examines the evolutionary origins of human dietary and activity patterns, and their implications for understanding modern health problems. Humans have evolved distinctive nutritional characteristics associated the high metabolic costs of our large brains. The evolution of larger hominid brain size necessitated the development of foraging strategies that both provided high quality foods, and required larger ranges and activity budgets.  Over time, human subsistence strategies have become ever more efficient in obtaining energy with minimal time and effort.  Today, populations of the industrialized world live in environments characterized by low levels of energy expenditure and abundant food supplies contributing to growing rates of obesity.

Drawing on data from the US and traditional, subsistence-level societies, I consider the roles of both diet and energy expenditure in contributing to the rising obesity rates in our modern world. These analyses suggest that the dramatic rise in obesity in the US cannot be explained solely by increased energy consumption. Rather, declines in activity are also important. Additionally, it appears that recent recommendations on physical activity have the potential to bring daily energy expenditure levels of industrialized societies surprisingly close to those observed among subsistence-level populations. These findings highlight the importance of linking physical activity and dietary recommendation in promoting nutritional health.