Sleep reduction linked to weight gain and metabolic changes

A study published in the Annals of Internal Medicine indicates that moderate, prolonged sleep reduction can lead to weight gain and metabolic changes. Researchers from Columbia University Irving Medical Center conducted two randomized clinical trials involving 95 adults who typically slept seven or more hours per night and faced elevated cardiometabolic risks.

Over a six-week period, participants were instructed to delay their bedtime, resulting in an average reduction of approximately 78 minutes of sleep per night. This reduction brought average sleep time down from roughly 7 hours and 26 minutes to about 6 hours and 8 minutes. The findings showed an average weight increase of 0.45 kilograms (450 grams), an average increase of 0.52 centimeters in waist circumference, and an increase in daily sedentary behavior by 17 minutes.

Medical experts note that sleep deprivation can disrupt the circadian rhythm and the balance of hormones such as ghrelin, which stimulates hunger, and leptin, which signals satiety. While the study observed weight and waist circumference changes, researchers noted that the weight gain was not accompanied by detectable changes in the ratio of body fat to muscle mass.