Jan. 9, 2009 -- If you're looking for a way to cut down on snacking, you might want to get more sleep.

That's according to a new study of 11 adults whose sleep and eating patterns were studied at the University of Chicago's sleep research lab.

Participants spent two weeks getting only 5 1/2 hours of sleep a night. At least three months later, they went back to the sleep lab and spent two weeks sleeping for 8 1/2 hours per night.

Throughout that time, participants were provided meals and they had unlimited access to snacks. The researchers -- who included Arlet Nedeltcheva, MD, of the University of Chicago -- monitored what participants ate, down to the nibble.

Participants averaged 220 extra calories from snacks -- mainly carbohydrates eaten at night -- on the days after sleeping only 5 1/2 hours, compared to after sleeping 8 1/2 hours.

Participants weren't especially active during their extra hours of time awake. So their extra snacking when they had little sleep created a bloated calorie tab, setting them up for weight gain.

Nedeltcheva's study appears in January's edition of The American Journal of Clinical Nutrition.