An hour spent playing video games may make teenage boys eat more over the rest of the day, a small study suggests.

The study, of 22 normal-weight teens, found that the boys ate a bigger lunch when they had a pre-meal video game, versus an hour spent relaxing. And they did not make up for the extra bites by burning more calories through gaming, or by eating less later in the day.

On average, the boys downed 163 calories more on the day when they played video games, researchers report in the American Journal of Clinical Nutrition.

Exactly what that means for video gamers' waistlines is unknown. But the findings add to studies that have linked kids' screen time - from TV and computers - to the odds of being overweight.

While those studies observed patterns, and do not prove cause-and-effect, the current study actually tested the idea that something about video-gaming itself might affect eating habits, explained lead researcher Jean-Philippe Chaput.

It's not clear why boys ate more on game day, according to Chaput, who researches obesity and lifestyle at the Children's Hospital of Eastern Ontario Research Institute in Ottawa, Canada.