According to researchers at Columbia University, adults who consistently slept about 80 minutes less each night for six weeks gained an average of one pound and became more sedentary.
Getting less sleep doesn't just leave you feeling tired, it may also contribute to gradual weight gain and increase your risk for chronic disease. According to researchers at Columbia University, adults who consistently slept about 80 minutes less each night for six weeks gained an average of one pound and became more sedentary.
"Our study shows that getting adequate sleep may help reduce the risk of weight gain and obesity-related conditions like heart disease and diabetes," says Marie-Pierre St-Onge, a professor of nutritional medicine in Columbia's Department of Medicine and Institute for Human Nutrition. "People tend to gain weight over the course of their adulthood, and obesity is a major risk factor for heart disease. But focusing on eating a healthier diet and getting more physical activity to offset weight gain is simplistic and can be difficult to maintain."
Previous research has linked poor sleep with weight gain, but many of those studies relied on extreme sleep deprivation - often limiting participants to just four hours of sleep per night for a short period. While those studies demonstrated that severe sleep loss can increase appetite and overeating, they did not reflect the sleep habits of most adults.
"These studies only show us what happens under the most extreme conditions and don't tell us if mildly sleep-deprived people, like a lot of Americans who get 5 or 6 hours of sleep a night, will gain weight," St-Onge says.
To better understand the effects of more realistic sleep loss, researchers recruited 95 adults who normally slept between seven and eight hours each night. During one six-week phase of the study, participants delayed their bedtime by 90 minutes. During another six-week phase, they maintained their normal sleep schedule.
Throughout both phases, researchers monitored sleep patterns and physical activity using wrist-worn devices. They also measured body weight, waist circumference, body composition, and fasting levels of hormones involved in regulating appetite.
Although participants gained only about one pound during the six-week period of reduced sleep, researchers say the long-term implications could be significant.
"While the 1-pound weight gain observed with modest sleep curtailment is not overwhelming, it is important to remember this is occurring over just six weeks," says Faris Zuraikat, assistant professor of nutritional medicine in Columbia's Department of Medicine and Institute for Human Nutrition. "Our study was designed to mimic sleep patterns that most adults experience chronically. When extrapolated to a full year, we would expect that losing less than an hour and a half of sleep per night could result in clinically meaningful weight gain."
The study also found that participants spent more time being inactive when they were sleep deprived. On average, sedentary time increased by 17 minutes per day, with men and postmenopausal women becoming inactive for nearly 30 additional minutes each day.
"Even when we accounted for the fact that they were awake longer when sleep was shortened, participants spent more time being inactive than when they got adequate sleep," Zuraikat says. "This is notable, as people who are more sedentary have an elevated risk for chronic diseases."
The findings build on earlier research involving many of the same participants. In one previous study, women with elevated cardiometabolic risk who reduced their sleep by about 80 minutes each night for six weeks developed greater insulin resistance, a key risk factor for type 2 diabetes. The effect was especially pronounced among postmenopausal women.
