A new study published in PNAS suggests that diet is the major driver of weight gain and obesity in modern society, contradicting the long-held assumption that a lack of physical activity is to blame. Researchers found that people from different cultures and countries with varying levels of sedentary behavior burned similar amounts of calories per day. Instead, they attribute the high rates of obesity in some populations to the type of diet consumed, particularly ultra-processed foods. The study’s findings have significant implications for the public health message on obesity, shifting the focus from exercise to dietary changes.
Source: https://www.npr.org/2025/07/24/nx-s1-5477662/diet-exercise-obesity-nutrition