A new study by Dr. Herman Pontzer, an Associate Professor of Anthropology at Hunter College, shows that humans and other primates burn 50% fewer calories each day than other mammals of similar size. The study, “Primate Energetics and Life History,” which appears in the journal Proceedings of the National Academy of Sciences, suggests that this slow metabolism may help explain why humans and other primates grow up slower and live longer than most mammals.
Pontzer and a team of international scientists examined 17 primate species in zoos, sanctuaries and in the wild. Using a safe and non-invasive technique, they measured the number of calories the primates burned over a 10 day period.
“The results were a real surprise,” says Pontzer. “Humans, chimpanzees, baboons and other primates expend only half the calories we’d expect for a mammal. To put that in perspective, a human – even someone with a very physically active lifestyle – would need to run a marathon each day just to approach the average daily energy expenditure of a mammal their size.”
The study also found that primates in captivity expend as many calories each day as their wild counterparts, suggesting that physical activity may have less of an impact on daily energy expenditure than was previously believed.
Results from this study hold intriguing implications for understanding health and longevity in humans. Linking the rate of growth, reproduction and aging to daily energy expenditure may shed light on the processes by which our bodies develop and age. And unraveling the surprisingly complex relationship between physical activity and daily energy expenditure may improve our understanding of obesity and other metabolic diseases.
More detailed study of energy expenditure, activity and aging among humans and apes is already underway. “Humans live longer than other apes, and tend to carry more body fat,” says Pontzer. “Understanding how human metabolism compares to our closest relatives will help us understand how our bodies evolved, and how to keep them healthy.”
Follow this link to read the abstract.