Playing a lot of sports or being physically active will not prevent children who eat a lot of junk food from gaining weight.

The researchers found that those who ate junk food had rounder stomachs regardless of the amount of physical activity they did.
“Until now it was thought even with an unbalanced diet, you somehow compensated for it if you got plenty of physical exercise. In this study we have shown that this is not the case. Adolescents are a risk group as far as lifestyles are concerned because they are starting to take their own decisions about what they want and do not want to eat, and they are also going through a period in which many of them have stopped doing any sport”, Dr Labayen said.
Source-Medindia