February 16, 2013
Study Examines Evolutionary Origins Of Human Dietary Patterns, Activities
April Flowers for redOrbit.com — Your Universe Online
A new study by William Leonard at Northwestern University on the diets and ways of prehistoric populations reveals the transition from subsistence to a modern, sedentary lifestyle has created energy imbalances that have increased rapidly on an evolutionary timescale. The findings, presented this week at the annual meeting of the American Association for the Advancement of Science (AAAS), show these imbalances play a major role in obesity.Leonard, chair and professor of anthropology in the Weinberg College of Arts and Sciences at Northwestern University, was unable to attend. His research was presented by a colleague as part of the symposium, The Scars of Human Evolution.
The study examines the evolutionary origins of human dietary and activity patterns in terms of their implications for understanding modern health problems. The presenter will examine the roles of both diet and energy expenditure in contributing to the rising obesity rates in the modern world using data drawn from the U.S. and traditional, subsistence-level societies.
Evolutionary perspectives on human dietary consumption and nutritional health have garnered greater attention over the last 25 years from both anthropologists and nutritional scientists. The high metabolic costs of our large brains have forced humans to evolve distinctive characteristics.
“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,” Leonard said.
“Over time, human subsistence strategies have become 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.”
Leonard has extensive field research gained from traveling the world to conduct research. The main focus of his research has been on biological anthropology and the adaptability, nutrition and growth and development of people in South America, Siberia and the United States.
Leonard was a consultant on the program, "I Caveman" which aired on the Discovery Channel in October 2011. The program examined how well modern-day humans could adapt to a traditional hunting and gathering way of life in high-altitude Colorado. The participants were evaluated for changes in body weight and health status over the course of the experiment. All ten participants lost weight, experienced significant improvements in blood pressure, cholesterol and blood glucose levels. These results were achieved while following a typical Paleolithic lifestyle, consuming a diet of game, fish and wild plant foods.