By Michael Breus, PhD, ABSM
Are you keeping an eye on your weight this holiday season, hoping to avoid adding the extra pounds that often result from the excesses and indulgences of the season? Here’s a weight-control strategy you may not have considered, but absolutely should: get a good night’s sleep.
Sleep is a powerful tool for weight management. Getting sufficient sleep—for most of us that means 7-8 hours a night—can help keep your appetite in check, curb cravings, and reduce late-night noshing. The problem is that many of us just aren’t getting that much sleep on a regular basis. And sleep deficiency can make controlling weight much more difficult.
A comprehensive new review of research related to sleep and weight gives us some perspective on what we’ve learned about the complicated relationship between the two. Researchers examined studies from the past 15 years on the possible influence of partial sleep deprivation and weight control. They emerged with a broad consensus: partial sleep deprivation appears to have a significant impact on weight—how easily it is gained, lost, and maintained. Partial sleep deprivation, in this case, is defined as sleeping fewer than six hours per night. The Centers for Disease Control estimates that nearly one-third of working adults in the U.S. are sleeping no more than 6 hours per night, an indication of just how broadly lack of sleep may be contributing to our culture’s problems with weight.
This review revealed consensus among multiple studies about some of the ways that sleep can influence weight. Partial sleep deprivation disrupts the normal levels of two hormones that are critical to regulating hunger and appetite: ghrelin and leptin. I’ve written before about the role that these hormones play in the sleep-weight connection. Studies show that even mild and short-term sleep deprivation can result in imbalances to these hormones that govern appetite.
Ghrelin is a fast-acting hormone, produced in cells of the stomach, which spurs appetite and drives us to eat. Ghrelin may particularly increase appetite for high-calorie foods. There’s evidence that ghrelin may also direct fat towards the midsection of the body, where it is most dangerous to health. When the body is deprived of sleep, production of ghrelin increases. Research shows that even a single night of sleep deprivation can elevate ghrelin levels—and appetite.
Leptin is a hormone that suppresses appetite by communicating to receptors in the brain that the body has the energy it needs to function, and doesn’t need to take on more. Leptin is produced in white fat cells throughout the body. The amount of fat in the body, then, influences the amount of leptin produced. When leptin levels are lower than normal, we’re less likely to feel full after eating. Food also appears more enticing to people with low leptin levels, according to research. Low sleep suppresses leptin production, making us more likely to feel ongoing pangs of hunger. Even short-term sleep deprivation has been shown to reduce leptin levels.
With these hormonal imbalances at work, it’s little surprise that sleep-deprived people are more likely to gain weight and to have difficulty maintaining a healthy weight. More than a third of adults in the US are obese, as are 17 percent of children, according to the Centers for Disease Control. Obesity, with its increased risks for many serious health problems—including diabetes, heart disease, stroke, and some types of cancer—is arguably our nation’s leading public health problem. A recent study by the CDC projects that half of all adults in the U.S. will be obese by the year 2030. Our collective weight problem endangers millions of lives and costs billions of dollars.
Researchers found that many studies conducted over the past 15 years reached similar conclusions about the influence of sleep on appetite hormones, and the consequences for weight. Their findings also suggest other areas of sleep-weight study that merit additional investigation:
The influence of sleep deprivation on energy expenditure: Does sleep deprivation diminish the effectiveness of our body to burn calories?
The effect of sleep deprivation on the quality of weight loss: Does sleep deprivation have an effect on the type of weight we lose? Does going without sufficient sleep make us more inclined to hang on to fat and shed non-fat soft tissue, like muscle?
One thing is certain: with the numbers of people currently overweight and obese—and the millions more expected to join their ranks in the coming years—we can’t afford to overlook any treatment or lifestyle adjustment that could make a difference in our battle against the bulge. Getting enough sleep on a regular basis continues to prove a challenge for millions of people. Millions, too, are struggling to lose weight or to maintain a healthy weight. In order to make a real difference in the fight against obesity, we’re going have to get a lot more serious about improving our sleep.
So when you’re strategizing to keep the pounds off through the holidays, why not make 8 hours of sleep a night part of your plan?
Michael J. Breus, PhD
The Sleep Doctor™