Getting just a little less sleep each night can have a bigger impact on your health than you think. Researchers at Columbia University Vagelos College of Physicians and Surgeons found that adults who cut their sleep time by about 80 minutes each night over a six-week period gained an average of 1 pound and spent more time inactive.
The findings add to the evidence that consistently getting enough sleep may play an important role in preventing weight gain and lowering the risk of obesity-related diseases.
“Our study shows that getting enough sleep may help reduce weight gain and the risk of obesity-related diseases such as heart disease and diabetes,” said study leader Marie-Pierre St-Onge, professor of nutritional medicine at Columbia University School of Medicine and the Institute of Human Nutrition. “People tend to gain weight as they reach adulthood, and obesity is a major risk factor for heart disease. But focusing on eating healthier and doing more physical activity to offset weight gain can be naive and difficult to maintain.”
Overcoming extreme sleep deprivation
Much of the previous research linking sleep deprivation and obesity focused on severe sleep deprivation, where people were often limited to just four hours of sleep. These studies show that extreme sleep deprivation increases appetite and overeating, which can be a contributing factor to weight gain.
However, such severe sleep restrictions are difficult for most people to tolerate for more than a few days.
“These studies only show what happens under the most extreme conditions; they don’t tell us whether people who are mildly sleep-deprived, like many Americans who get five or six hours of sleep a night, will gain weight,” St. Onge says.
To better reflect real life, researchers looked at the effects of chronic mild sleep deprivation, which is experienced by about 30% of adults.
Six weeks of sleep deprivation brought about visible changes
The study involved 95 adults who typically slept seven to eight hours a night. During the six-week study period, participants delayed their usual bedtime by 90 minutes. For another six weeks, they followed a normal sleep schedule.
During both phases, participants wore wrist monitors that tracked their sleep and physical activity. The researchers also measured fasting levels of several hormones involved in regulating weight, waist circumference, body composition, and appetite.
“While the 1-pound weight gain observed with moderate sleep restriction is not surprising, it is important to remember that this is occurring over just six weeks,” says Faris Zuraikat, assistant professor of nutritional medicine at Columbia University School of Medicine and the Institute of Human Nutrition and lead author of the study. “Our study was designed to mimic the sleep patterns most adults experience chronically. Extrapolating over a full year, we would expect that losing less than 1.5 hours of sleep each night could result in clinically meaningful weight gain.”
Less sleep means more time sitting
The researchers found that participants became less active during the sleep restriction phase. On average, sedentary time increased by 17 minutes per day. In men and postmenopausal women, physical inactivity increased by nearly 30 minutes each day.
“When they got less sleep, participants spent more time inactive than when they got enough sleep, even accounting for the fact that they were awake longer,” Zuraikat says. “This is noteworthy because sedentary people are at higher risk of chronic disease.”
Previous research suggests broader health effects
The same group of participants was also investigated in a related study. One previous study reported that women at high cardiometabolic risk who reduced their sleep by about 80 minutes each night over a six-week period increased insulin resistance, an important risk factor for type 2 diabetes. This effect was particularly pronounced in postmenopausal women.
Another study found that men and women at high risk for heart disease develop an influx of inflammatory cells into their hearts after undergoing mild sleep restriction.
“While further research is needed to better understand how sleep restriction leads to weight gain, both of our findings suggest that sleep deprivation increases the risk of obesity-related diseases such as type 2 diabetes and heart disease,” Professor St. Onge said.
“Now we need to understand the health implications of improving sleep for people who don’t get enough sleep on a regular basis.”
The study, titled “Sleep Skimming and its Effects on Weight and Body Composition: A Pooled Analysis of Randomized Trials,” was published July 6 in the journal Science. Annual report of internal medicine.
Authors are Faris Zuraikat, Samantha Scaccia, Justin Cochran, Bin Cheng, Keith Diaz, Seth Creasy (University of Colorado), Brooke Aggarwal, Sanja Jelic, and Marie-Pierre St-Onge.
The authors report no conflicts of interest.
This study was supported by the American Heart Association (16SFRN27950012) and the National Institutes of Health (R01 HL128226, UL1 TR001873, P30 DK026687, R01 HL173190, R01 HL155190, R01 HL153642, K01 HL145023, R01) received support. HL169991, R01 HL106041, R35 HL155670, R01 AG071032, R56 DK136601, P30 DK048520, and R01 DK128154).
