You know you should get about 8 hours of sleep each night, but with after-school activities, papers to write, tests to study for, and trying to squeeze at least a little TV and friend time in, that's pretty tough. Well, here's a little extra incentive to hit the sack sooner.

A new study observed 723 teens and recorded their sleep patterns during the week and on weekends, how often they had trouble sleeping, and how many calories their diet typically consisted of. What researchers found is a link between sleep deprivation and a higher body mass index, which means you're likely to gain weight if you're burning the midnight oil too often.

"Sleep has long been recognized as an important health behavior," says Leslie Lytle, who headed the study. "We are just beginning to recognize its relationship to overweight and obesity in children and adults alike."
Is it hard for you to make time for 8 hours of sleep each night?