(RxWiki News) Want to lose weight? Then exercise more, right? No doubt physical activity is important for weight loss. But so is laying down, closing your eyes and getting enough sleep.
A recent editorial by two obesity researchers discusses how important a good night's sleep is to helping people lose weight or simply avoid gaining it in the first place.
"Get at least 8 hours of sleep."
The editorial, written by Jean-Philippe Chaput, PhD, and Angelo Tremblay, PhD, discusses the increasing evidence that sleep plays an important part in achieving or maintaining a healthy weight.
Dr. Chaput is a part of the Healthy Active Living and Obesity Research Group at the Children’s Hospital of Eastern
Ontario Research Institute in Canada, and Dr. Tremblay is from the Department of Kinesiology at Laval University in Québec.
"Chronic sleep restriction is pervasive in modern societies, and there is robust evidence supporting the role of reduced sleep as contributing to the current obesity epidemic," they write early on in their commentary.
Among the evidence they cite is research showing that not getting enough sleep can interfere with the reward centers of the brain. This interference may increase a person's desire to eat more.
The authors also mention research on sleep deprivation's impact on several important hormones: leptin, ghrelin and cortisol.
Leptin is the hormone that helps the body know when it has had sufficient food. Not having enough leptin will prevent a person from feeling satisfied.
Ghrelin is the "hunger hormone." If you have higher levels of ghrelin in your body, you will feel hungrier.
Cortisol is popularly called the "stress hormone" because its levels are higher when a person is under more stress.
Higher levels of cortisol activates the body's "fight or flight" response. This "alarm system" of your body shifts you into more of a survival mode of sorts, which increases your blood sugar.
If you're not getting enough sleep, the balance of these hormones in your body can get out of whack, and that makes it harder to regulate your food intake.
The editorial also describes a recent study looking at how well two groups of people did in losing weight on the same diet — one group got enough sleep and the other did not.
The study participants were given 5.5 hours or 8.5 hours to sleep each night for two weeks. At the same time, they were eating a lower calorie diet, with an average 680 calories less than they would normally eat.
The people who slept 5.5 hours a sleep lost 55 percent less body fat and 65 percent more muscle mass than the people who slept 8.5 hours a night.
Overall, the people who got 8.5 hours of sleep burned about twice as many calories each day as those only getting 5.5 hours of sleep.
The shorter sleepers were also hungrier than the ones who got up to 8.5 hours to sleep.
The authors said that the findings of this study might explain why it's harder for people to follow a good diet if they're not getting enough sleep.
They discussed other studies that showed a link between sleep deprivation and lower success with weight loss, and they mentioned one study that used behavioral interventions to help people sleep more.
The result? The people who starting sleeping a healthier amount then craved fewer sweet and salty foods and were more willing to exercise.
The ways that poor sleep can interrupt otherwise positive dietary programs is important to consider, according to William Kohler, MD, the director of the Florida Sleep Institute in Spring Hill, Florida.
"You have patients who are going through various dietary programs to lose weight and the programs are being interfered with because of insufficient sleep," he said.
"This article points out one of the potential causes for difficulty with losing weight and contains important information that is accumulating on the need for sufficient quantity and quality of sleep," Dr. Kohler added.
However, the authors stopped short of saying that sleeping more is a simple way to avoid obesity.
"Successful weight management is complicated, and a good understanding of the root causes of weight gain and barriers to weight management is essential to success," they wrote. "The solution is not as simple as 'eat less, move more, sleep more.'”
But they do say that lifestyle changes intended to get someone to a healthy weight should be sure to include getting a sufficient amount of sleep every night.
The editorial was published September 17 in the Canadian Medication Association Journal. The paper required no funding, and the authors had no disclosures.