STATE COLLEGE, Pa. -

Not getting enough sleep may do more than just make you tired -- it could also cause you to gain weight.

According to a new study fron researchers at Penn State, sleep deprivation can affect hormones in your body, which can slow down your metabolism, cause you to burn less fat, and make you hungrier.

Researchers say more than 35 percent of American adults are obese, and more than 28 percent get less than six hours of sleep each night.