A new study from Columbia University reveals that losing just 80 minutes of sleep per night can lead to a weight gain of one pound every six weeks, along with increased sedentary behavior. The research, published in Annals of Internal Medicine, suggests that about a third of adults who get five to six hours of sleep nightly may be at risk.
Study Design and Findings
The study recruited 95 adults who typically slept seven to eight hours per night. Participants were instructed to delay their bedtime by 90 minutes for six weeks, then return to their usual sleep schedule for another six weeks. Wrist monitors tracked sleep, while researchers recorded changes in body weight, waist circumference, body composition, and fasting hormone levels related to appetite.
Results showed that during the sleep-restricted phase, participants gained an average of one pound. Sedentary time increased by 17 minutes per day overall, and by nearly 30 minutes per day for men and postmenopausal women.
Expert Commentary
Study leader Marie-Pierre St-Onge, professor of nutritional medicine at Columbia, said: “Our study shows that getting adequate sleep may help reduce the risk of weight gain and obesity-related conditions like heart disease and diabetes.” She added that “people tend to gain weight over the course of their adulthood, and obesity is a major risk factor for heart disease.”
First author Faris Zuraikat, assistant professor of nutritional medicine at Columbia, noted: “While the one-pound weight gain observed with modest sleep curtailment is not overwhelming, it is important to remember this is occurring over just six weeks. 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.”
Health Implications
Previous studies on the same participants found that women with increased cardiometabolic risk who shortened sleep by around 80 minutes nightly over six weeks had increased insulin resistance, a risk factor for type 2 diabetes. Effects were more pronounced in postmenopausal women. Another study found that men and women with elevated heart risk had an influx of inflammatory cells in the heart after losing sleep.
Prof St-Onge concluded: “Though more research is needed to further understand how sleep restriction leads to weight gain, all of our findings suggest that insufficient sleep increases the risk of obesity-related conditions like type 2 diabetes and heart disease. Now we need to understand the health effects of improving sleep in those who fail to get adequate sleep on a regular basis.”
