Diet—not a lack of exercise—is main driver of obesity, study finds
No matter where people live, and no matter how active they are, it’s what they eat that appears to drive obesity, according to a major new study.
The study, published July 14 in the journal PNAS, was co-authored by an international team of collaborators, including Eric Rimm, professor in the Department of Epidemiology at Harvard T.H. Chan School of Public Health.
The study looked at the total calories burned per day for more than 4,200 adult men and women from 34 different countries and cultures, from hunter-gatherers and farmers—who typically have low obesity rates—to people living in industrial nations, where obesity rates are higher. The researchers were surprised to find that the number of calories people burn each day was similar across the various populations, even though they had different lifestyles and activity levels, according to a July 24 NPR article.
The finding suggests that, rather than a lack of physical activity, some other factor must be at play in explaining why some countries have higher obesity rates than others. “And that would be diet,” Harvard Chan School’s Deirdre Tobias told NPR. Tobias, an assistant professor in the Department of Nutrition who was not involved with the study, added, “This does sort of really fly in the face of what a lot of us anecdotally assumed was driving a lot of the weight gain and obesity today.”
Read the study: Energy expenditure and obesity across the economic spectrum
Read the NPR article: You can’t outrun a bad diet. Food—not lack of exercise—fuels obesity, study finds
