Spending hours on the Internet likely contributes to weight gain by taking time away from physical activity, according to Berkey's team.
Lack of sleep may make people too tired to be active during the day; sleep deprivation also affects hormones and metabolism in a way that might promote weight gain.
Meanwhile, alcohol contains a significant amount of calories, and research suggests that people usually don't make an adjustment for liquid calories by eating or drinking less throughout the rest of the day.
SOURCE: The Journal of Pediatrics, July 2008.
