Columbia study links mild sleep loss to weight gain and metabolic risks

A study conducted by researchers at Columbia University’s Vagelos School of Medicine indicates that chronic, mild sleep deprivation leads to weight gain and increased health risks. The research involved 95 adults with cardiovascular and metabolic risks who had their sleep reduced by approximately 80 minutes per night for six weeks. During the sleep-restricted period, participants gained an average of 0.45 kilograms and increased their sedentary time by 17 minutes per day. The study also found that insulin resistance increased in women, particularly postmenopausal women, and that immune cells became more prone to migrating to sites of inflammation.

Previous studies on sleep deprivation and obesity have largely focused on severe restrictions, such as limiting sleep to four hours a night, which have limited practical utility as few people can endure such restrictions for more than a few days. Chronic mild sleep deprivation, defined as getting five to six hours of sleep per night, is estimated to affect approximately 30 percent of adults. The original report was published in WIRED Japan and subsequently translated.

The study challenges previous assumptions that mild sleep deprivation increases appetite via hormone disruption; leptin levels, which suppress appetite, were actually higher during the sleep-restricted period. Extrapolating the six-week results suggests that chronic sleep deficits could lead to significant weight gain over a year. The effect on insulin resistance was particularly pronounced in postmenopausal women.

The findings suggest that even small, daily sleep deficits pose measurable health risks, challenging modern lifestyles that prioritise other activities over sleep. The study does not fully clarify the mechanisms by which mild sleep deprivation leads to weight gain, particularly given the unexpected rise in leptin levels. Further research is required to determine the extent to which reassessing daily sleep duration can help with weight management and the prevention of lifestyle-related diseases.

The long-term health benefits for individuals who are chronically sleep-deprived but improve their sleep duration remain to be fully understood. Marie-Pierre St-Onge, a professor at Columbia University specialising in nutritional medicine, noted that the findings suggest insufficient sleep increases the risk of obesity-related conditions like type 2 diabetes and heart disease. The team plans to investigate what health benefits people who are chronically sleep-deprived can gain by improving their sleep duration.