Cutting sleep by just 1.5 hours each night for six weeks led to meaningful weight gain in adults already at elevated cardiometabolic risk, according to a pooled analysis of two randomized trials published in the Annals of Internal Medicine. Participants who reduced their nightly sleep from at least 7 hours gained roughly 1 pound, saw waist circumference grow by half a centimeter, and spent about 17 more minutes per day sedentary compared to those who maintained normal sleep. Researchers from Columbia University note that this rate of weight gain mirrors typical annual weight trends in early and middle adulthood, suggesting chronic mild sleep loss could meaningfully drive obesity and heart disease risk over time. The findings strengthen the case for treating sleep duration as a frontline health conversation.
