Watching too much television, video games and Internet can increase body fat in teens. A five-year study from the University of Montreal and the Sainte-Justine Hospital Research Center has found teenagers have four different patterns of screen use: increasers, decreasers, consistently high and consistently low users.

Even teens from the consistently low group exceeded two hours per day of screen time on average. Yet organizations such as the American Academy of Pediatrics and the Canadian Paediatric Society recommend limiting screen use to two hours per day. Increasers and consistently high screen users had the greatest increases in percent body fat, while decreasers had the lowest gains in percent body fat.

The high levels of screen time observed in the study underscore the need for public health strategies to reduce overall screen time among youth. Encouraging less screen time, and some form of monitoring to prevent excessive increases in screen time through high school, would be beneficial to teenagers.