NEW DELHI– A new study suggests that rising global obesity rates are driven more by increased caloric intake than by a decline in physical activity, challenging the widely held belief that modern sedentary lifestyles are the primary cause of the obesity epidemic.
Researchers from Duke University in the United States found that people in wealthier, more industrialized nations actually expend as much—or even more—energy daily compared to those in less developed regions.
“It’s clear that changes in diet, not reduced activity, are the main cause of obesity,” said Herman Pontzer, lead investigator and Professor of Evolutionary Anthropology at Duke University.
Published in the journal Proceedings of the National Academy of Sciences (PNAS), the study analyzed thousands of data points related to daily energy expenditure, body fat percentage, and body mass index (BMI) from over 4,200 adults aged 18 to 60. The subjects represented 34 different populations across six continents.
While the researchers did observe a slight decrease in size-adjusted total energy expenditure with increasing economic development, this accounted for only a small portion of the rise in body fat seen in wealthier countries.
“This suggests that other factors—particularly dietary changes—are responsible for the increased body fat that accompanies economic development,” said Amanda McGrosky, the study’s lead author and a former postdoctoral researcher at Duke. McGrosky is now an assistant professor of biology at Elon University.
The study emphasizes that this does not diminish the importance of physical activity.
Instead, the findings support a growing consensus that diet and exercise should be viewed as complementary components of a healthy lifestyle, not as substitutes for one another.
“Diet and physical activity should be seen as essential and mutually reinforcing,” the study concluded.
Next, the research team aims to pinpoint the specific dietary factors in developed nations that are most responsible for the surge in obesity rates. (Source: IANS)
