More ZZZs can translate to fewer LBs, according to new research from the University of Colorado that found sleeping just five hours a night during a work week and having unlimited access to food caused participants to gain two pounds.

The study was performed in collaboration with the CU Anschutz Medical Campus. The findings suggest that getting a good night's rest could help battle the obesity epidemic.

"I don't think extra sleep by itself is going to lead to weight loss," said Kenneth Wright, director of CU-Boulder's Sleep and Chronobiology Laboratory, which led the study.

Wright said weight gain and obesity are more complex, but incorporating healthy sleep into weight loss can help people get to a healthier weight.

Previous research has shown that a lack of sleep can lead to weight gain, but the reasons for extra pounds were unclear. The new study is published today in the Proceedings of the National Academy of Sciences. Researchers show that, while staying awake longer requires more energy, the amount of food study participants ate more than offset the extra calories burned.

“Just getting less sleep, by itself, is not going to lead to weight gain,” Wright said in a news release. “But when people get insufficient sleep, it leads them to eat more than they actually need.”

For the study, researchers monitored 16 young, lean, healthy adults who lived for about two weeks at the University of Colorado Hospital, which is equipped with a “sleep suite” for controlling sleep opportunities — by providing a quiet environment and by regulating when the lights are on and off — and a sealed room that allows researchers to measure how much energy participants are using based on the amount of oxygen they breathe in and the amount of carbon dioxide they breathe out.

All participants spent the first three days with the opportunity to sleep nine hours a night and eating meals that were controlled to give participants only the calories they needed to maintain their weight in order to establish baseline measurements. But after the first few days, the participants were split into two groups: one that spent five days with only five hours to sleep in and one that spent five days with nine hours of sleep opportunity.

In both groups, participants were offered larger meals and had access to snack options throughout the day, ranging from fruit and yogurt to ice cream and potato chips. After the five-day period, the groups switched. On average, the participants who slept for up to five hours a night burned 5 percent more energy than those who slept up to nine hours a night, but they consumed 6 percent more calories.

Those getting less sleep also tended to eat smaller breakfasts but binge on after-dinner snacks. In fact, the total amount of calories consumed in evening snacks was larger than the calories that made up any individual meal. The current findings add to the growing body of evidence showing that overeating at night may contribute to weight gain.

Contact Camera Staff Writer Brittany Anas at 303-473-1132 or