If you've been trying to shed a few pounds, it might behoove you to get more shut-eye. New research presented at a meeting of the American Heart Association found that people who got less sleep consumed substantially more calories a day than those who had a good night's rest. Here, a brief guide to the study:

How did researchers conduct the study?
This small experiment, led by Dr. Andrew D. Calvin of the Mayo Clinic in Rochester, Minn., took a close look at the sleeping and eating habits of 17 people between the ages of 18 and 40. The researchers put the volunteers in a Big Brother-style house, and monitored how much they slept, what they ate, and the physical activities they engaged in. 

How were participants tested?
For the first three nights the participants slept as much as they wanted. (They averaged about 6.5 hours per night.) Then they were split into two groups: Nine kept their normal sleep patterns, while the other eight were only allowed to sleep for 5 hours and 10 minutes a night. This schedule continued for eight nights. The leaders of the study found that with food readily available, those who slept less ate, on average, 549 more calories per day, or a little more than they'd get eating a McDonald's Big Mac. And those who kept a normal sleep schedule actually ate 143 fewer calories per day, on average.

Why did this happen?
"A lot of people assume that if they are awake longer, they will move more and burn more calories," Calvin tells Web MD. But that isn't the case. Calvin says there was a negligible difference in the amount of physical activity between the two groups. Yet the size of the additional calorie intake turned out to be "enormous," says Dr. Eve Van Cauter of the University of Chicago, who wasn't involved with the study. The National Sleep Foundation recommends that adults get seven to nine hours of sleep a night, says Calvin. "If you are looking to maintain a healthy weight or lose weight, I think getting adequate sleep may be very important." 

Sources: CBS News, The Globe and Mail, Web MD, Telegraph