Obesity Risk May Be Driven More by What You Eat Than How Much You Exercise
August 11, 2025 | Source: Very Well Health | by Claire Bugos
Obesity is far more common among people living in more economically developed regions than those who live hunter-gatherer or pastoral lifestyles.1
McGrosky A, Luke A, Arab L, et al. Energy expenditure and obesity across the economic spectrum. Proc Natl Acad Sci. 2025;122 (29) e2420902122. doi:10.1073/pnas.2420902122 (2025).
Health experts have long pointed to sedentary lifestyles in industrialized countries as a significant cause of soaring obesity rates there.
A recent study published in the journal PNAS challenges that assumption.1 Using massive datasets from dozens of countries, researchers found strong similarities in the daily energy expenditure of people across the socioeconomic spectrum: American office workers burn roughly the same number of calories as herder-farmers in Siberia, horticulturalists in Bolivia, and hunter-gatherers in Tanzania.
The findings suggest that diet, rather than physical activity, drives obesity risk.