I know there’s a bunch of you sitting at work right now with nothing to read because we haven’t been posting workouts every day. Naked windmills can only take you so far… Our apologies for not providing entertainment for your coffee break, however, Coach Melisa dug up this article on sleep and weight management for your reading pleasure. Enjoy…
Can more sleep really help us control our weight?
Three top experts explore the possibilities.
By Colette Bouchez
Lose weight while you sleep. It sounds like something you’d hear on a late night infomercial — just around the time you are reaching for that bag of cookies because, well, you can’t sleep.
But as wild as the idea sounds, substantial medical evidence suggests some fascinating links between sleep and weight. Researchers say that how much you sleep and quite possibility the quality of your sleep may silently orchestrate a symphony of hormonal activity tied to your appetite.
“One of the more interesting ideas that has been smoldering and is now gaining momentum is the appreciation of the fact that sleep and sleep disruption do remarkable things to the body — including possibly influencing our weight,” says David Rapoport, MD, associate professor and director of the Sleep Medicine Program at the New York University School of Medicine in New York City.
While doctors have long known that many hormones are affected by sleep, Rapoport says it wasn’t until recently that appetite entered the picture. What brought it into focus, he says, was research on the hormones leptin and ghrelin. First, doctors say that both can influence our appetite. And studies show that production of both may be influenced by how much or how little we sleep.
In fact, have you ever experienced a sleepless night followed by a day when no matter what you ate you never felt full or satisfied? If so, then you have experienced the workings of leptin and ghrelin.
Foods That Help or Harm Your Sleep and How Hormones Affect Your Sleep
Leptin and ghrelin work in a kind of “checks and balances” system to control feelings of hunger and fullness, explains Michael Breus, PhD, a faculty member of the Atlanta School of Sleep Medicine and director of The Sleep Disorders Centers of Southeastern Lung Care in Atlanta. Ghrelin, which is produced in the gastrointestinal tract, stimulates appetite, while leptin, produced in fat cells, sends a signal to the brain when you are full.
So what’s the connection to sleep? “When you don’t get enough sleep, it drives leptin levels down, which means you don’t feel as satisfied after you eat. Lack of sleep also causes ghrelin levels to rise, which means your appetite is stimulated, so you want more food,” Breus tells WebMD.
The two combined, he says, can set the stage for overeating, which in turn may lead to weight gain.
How the hormones leptin and ghrelin set the stage for overeating was recently explored in two studies conducted at the University of Chicago in Illinois and at Stanford University in California.
In the Chicago study, doctors measured levels of leptin and ghrelin in 12 healthy men. They also noted their hunger and appetite levels. Soon after, the men were subjected to two days of sleep deprivation followed by two days of extended sleep. During this time doctors continued to monitor hormone levels, appetite, and activity.
The end result: When sleep was restricted, leptin levels went down and ghrelin levels went up. Not surprisingly, the men’s appetite also increased proportionally. Their desire for high carbohydrate, calorie-dense foods increased by a whopping 45%.
It was in the Stanford study, however, that the more provocative meaning of the leptin-ghrelin effect came to light. In this research — a joint project between Stanford and the University of Wisconsin — about 1,000 volunteers reported the number of hours they slept each night. Doctors then measured their levels of ghrelin and leptin, as well as charted their weight.
The result: Those who slept less than eight hours a night not only had lower levels of leptin and higher levels of ghrelin, but they also had a higher level of body fat. What’s more, that level of body fat seemed to correlate with their sleep patterns. Specifically, those who slept the fewest hours per night weighed the most.
One theory also says that it may not be the level of this hormone that matters so much as a person’s individual response to it. In much the same way that obese people can become resistant to insulin, some folks may be resistant to the fullness signal that leptin sends to the brain.
“It’s like the body is trying to tell them to stop eating, but their brain just isn’t getting the message,” says Breus.
Another theory: The overall response to leptin may be more individual than we think. Experts say our environment, dietary habits, exercise patterns, personal stress levels, and particularly our genetics may all influence the production of leptin and ghrelin, as well as our response to them.
The fact that we don’t know all the factors causes at least some experts to view all the research on sleep and weight with a cautious or skeptical eye.
“There is a serious challenge to the closing of the loop. That isn’t to say that what we know about leptin and ghrelin is not important, or that when we finally do understand it that it won’t be crystal clear — but right now it just isn’t,” Rapoport tells WebMD.
Breus agrees: “I think we are likely to find that bad sleep matters but that it’s likely to be bad sleep plus some other problems. I don’t think we know what they are yet.”
Sleep: You Can’t Lose
Until doctors do know more, most experts agree that if you are exercising and following a sound nutrition plan, logging in a few extra hours of sleep a week is not a bad idea, particularly if you get six hours of sleep or less a night. You may just discover that you aren’t as hungry, or that you have lessened your craving for sugary, calorie-dense foods.
“One thing I have seen is that once a person is not as tired, they don’t need to rely on sweet foods and high carbohydrate snacks to keep them awake — and that automatically translates into eating fewer calories,” says Breus.
Says Roca: “As research continues, more and more data comes to the forefront to suggest that you simply can’t cut back on sleep without paying some price.”