December 07, 2004

Researchers say they have discovered a link between a lack sleep and obesity.

According to a Stanford University School of Medicine study, people who slept less than eight hours had increased levels ghrelin, a hormone that triggers eating, and lower levels of leptin, a hormone that tells the body it's full.

The study included 1,024 volunteers from a Wisconsin Sleep Cohort Study. The scientists found people who slept consistently for five hours had a 14.9 percent increase in ghrelin and a 15.5 percent decrease in leptin, compared with those who reported sleeping eight hours.

"In Western societies, where chronic sleep restriction is common and food is widely available, changes in appetite regulatory hormones with sleep curtailment may contribute to obesity," the researchers noted.

The study appears in the online issue of Public Library of Science.