Even Mild Sleep Deprivation May Lead to Weight Gain

Many studies examining the link between sleep deprivation and obesity have focused on severe sleep deprivation, such as restricting participants’ sleep to about four hours a night. These studies suggest that this may lead to increased appetite and overeating, which in turn could contribute to weight gain.

Because very few people can endure such severe sleep restrictions for more than a few days, though, the practical utility of this research is limited, and it hasn’t necessarily clarified whether more common and milder types of sleep deprivation, such as getting five to six hours of sleep per night, actually lead to weight gain.

This is the backdrop for a recent study by a research team at Columbia University’s Vagelos School of Medicine, which revealed that chronic, mild sleep deprivation—which is estimated to affect about 30 percent of adults—can lead to weight gain.

“Our study shows that getting adequate sleep may help reduce the risk of weight gain and obesity-related conditions like heart disease and diabetes,” explained Marie-Pierre St-Onge, a professor at Columbia University specializing in nutritional medicine, in a release.

St-Onge and her research team studied 95 adults who typically slept at least seven hours a day and had cardiovascular and metabolic risks. These participants were asked to delay their bedtime by 90 minutes for six weeks, and their sleep duration and physical activity were recorded using wrist-worn monitors.

For another six weeks, the participants maintained their usual sleep schedules. During both periods, the researchers measured the participants’ weight, waist circumference, body composition, and the fasting blood levels of several hormones involved in appetite regulation.

Analysis revealed that during the period when bedtime was delayed and sleep duration was reduced by approximately 80 minutes, participants’ average weight increased by about 0.45 kilogram—about a pound—compared to the period when they slept normally. Extrapolating these results over a year, significant weight gain could be associated with chronic sleep deprivation.

In addition, during the sleep-restricted period, the average amount of time spent sitting increased by 17 minutes per day. When limited to men and postmenopausal women, sedentary time increased by nearly 30 minutes per day. In other words, even accounting for the longer time spent awake, participants spent more time sitting than when they got enough sleep.

On the other hand, levels of leptin—a hormone that suppresses appetite—were actually higher during the period of sleep restriction. The theory put forward by studies on severe sleep restriction that disruptions in hormones leads to overeating does not apply, at least as far as leptin is concerned.