Is There a Link Between Sleep Deprivation and Obesity?
For decades, we’ve been trained to think about weight as it relates to physical activity—as in, regular workouts are key to maintaining a healthy body weight. Yet as scientists’ understanding of obesity has evolved, it’s become clear that the relationship between exercise and weight isn’t quite so straightforward (nor is weight loss as simple as “calories in, calories out”). In fact, research shows that, as counterintuitive as it might sound, inactivity might be just as important as hitting the gym when it comes to achieving a healthy body weight and preventing obesity. More specifically, we’re talking about the importance of getting a good night’s sleep.
A growing body of evidence is exploring powerful links between sleep deprivation and the prevalence of obesity. In fact, many people increasingly view sleep deprivation and obesity as parallel epidemics, says clinical sleep educator Terry Cralle, RN, a Better Sleep Council representative. The relationship between sleep and weight is complex, but a few things are clear: “Sleep deprivation will lead to a decrease in metabolism, an increase in appetite, and a decrease in physical activity,” Cralle says.
Now, before you say, “Sleep deprivation—that’s not about me,” this term doesn’t just apply to people who routinely stay up until 2 a.m. watching TV and then wake at 6 a.m. for work (although that definitely counts). It can also just mean that you chronically fall short of the seven to nine hours of sleep recommended for adults. While going to bed an hour or two later might not feel like a huge deal the next day, falling just one or two hours short on sleep over the course of weeks or months has been shown to have a measurable impact on our waistlines.
Studies have shown that people who sleep less than seven hours a night (about one third of Americans, according to the Centers for Disease Control and Prevention) are more likely to have a higher body mass index (BMI) and are at higher risk of obesity than people who sleep the recommended number of hours. Other research has shown that people who sleep less than six hours a night are at increased risk for type 2 diabetes. Also important to note: Sleep deprivation isn’t just about the amount of sleep you get; it can also mean that the quality of your sleep is poor because, for example, you wake up frequently due to a partner’s snoring, or because of work stress, or because you’re a parent of little kids.
Whatever the reasons that someone isn’t clocking enough Zs, there are several ways in which sleep deprivation makes weight management more challenging. For starters, “Chronic sleep deprivation can reduce the body’s resting metabolic rate, meaning we burn fewer calories at baseline,” explains Dr. John Carter, director of the Center for Sleep Medicine at MetroHealth in Cleveland. Yet tired people typically have a higher caloric intake than people who sleep for a longer stretch. As you might have noticed, the day after a late night out, disrupted sleeping patterns often lead to nonstop snacking and cravings for high-calorie foods loaded with carbohydrates, which make us feel (temporarily) more upbeat. “When we’re tired, we’re more likely to reach for sugary foods and beverages to get a quick boost of energy,” says Dr. Christine Ren-Fielding, Professor of Surgery at NYU School of Medicine, Director of the NYU Langone Weight Management Program and Chief of the Division of Bariatric Surgery. Despite this increased food intake, our energy expenditure on tired days can be lower; when our energy balance is out of sync, this can lead to excess calories stored as fat.
