Simply put, being tired can cause weight gain.

A new study shows that being sleep deprived is a BIG problem if you're trying to control your weight.

Researchers have found that missing out on sleep makes you eat more than usual.

In this study, some people were allowed to sleep as much as they wanted, while others were allowed just two-thirds of their normal sleep time.

For those who didn't get all the sleep they needed, they ate an extra 549 calories per day...OR MORE!

Over one week's time, that could add up to a pound of weight gain!