Physical activity, not overeating, is key to preventing childhood obesity, a new review finds.

A new review by Professor Dick Telford challenges the idea that childhood obesity is mainly caused by overeating, finding that physical activity is more critical than diet in maintaining healthy weight. Active children, even those eating more, were leaner than less active peers, suggesting movement better balances energy use. The study criticizes past research for relying on unreliable BMI measurements and self-reported data, which distorted findings. It argues that inactivity—not overconsumption—is a key driver of weight gain, and promoting enjoyable, varied physical activity is a healthier, more effective strategy than restricting food.