Columbia study links 90 minutes of lost sleep to half-kilogram gain over six weeks

Researchers at Columbia University have found that sleeping about 90 minutes less per night leads to an average weight gain of roughly half a kilogram over a six-week period. Participants who had their sleep reduced showed lower physical activity compared with periods when they rested normally, according to the study. The researchers said sleep deprivation pushed people toward a more sedentary lifestyle, lowering daily calorie expenditure. On average, participants sat for about 17 extra minutes per day during sleep-restricted phases, a figure that climbed to roughly 30 minutes for men and some postmenopausal women. The study also noted that insufficient sleep affects hormones that regulate appetite, increasing cravings for high-fat and high-sugar foods. Researchers warned that chronic sleep loss is linked to higher risks of insulin resistance, type 2 diabetes, high blood pressure and heart disease. The team recommended basic sleep hygiene measures, including regular sleep schedules and reduced exposure to blue light in the evening. Scientists emphasized that while the link between sleep and weight gain is strong, it should be considered alongside factors such as diet and overall lifestyle.