Sleep Loss Limits Fat Loss

Cutting back on sleep reduces the benefits of dieting, according to a study published October 5, 2010, in the Annals of Internal Medicine. When dieters in the study got a full night’s sleep, they lost the same amount of weight as when they slept less. When dieters got adequate sleep, however, more than half of the weight they lost was fat. When they cut back on their sleep, only one-fourth of their weight loss came from fat. They also felt hungrier. When sleep was restricted, dieters produced higher levels of ghrelin, a hormone that triggers hunger and reduces energy expenditure.

“If your goal is to lose fat, skipping sleep is like poking sticks in your bicycle wheels,” said study director Plamen Penev, MD, PhD, assistant professor of medicine at the University of Chicago. “Cutting back on sleep, a behavior that is ubiquitous in modern society, appears to compromise efforts to lose fat through dieting. In our study it reduced fat loss by 55 percent.”

The study, performed at the University of Chicago’s General Clinical Resource Center, followed 10 overweight but healthy volunteers aged 35 to 49 with a body mass index ranging from 25, considered overweight, to 32, considered obese. Participants were placed on an individualized, balanced diet, with calories restricted to 90 percent of what each person needed to maintain his or her weight without exercise. Each participant was studied twice: once for 14 days in the laboratory with an 8.5-hour period set aside for sleep, and once for 14 days with only 5.5 hours for sleep. They spent their waking hours engaged in home- or office-like work or leisure activities. During the two-week, 8.5-hours-in-bed phase, volunteers slept an average of 7 hours and 25 minutes each night. In the 5.5-hour phase, they slept 5 hours and 14 minutes, or more than two hours less. The number of calories they consumed, about 1,450 per day, was kept the same.

The volunteers lost an average of 6.6 pounds during each 14-day session. During weeks with adequate sleep, they lost 3.1 pounds of fat and 3.3 pounds of fat-free body mass, mostly protein. During the short-sleep weeks, participants lost an average of 1.3 pounds of fat and 5.3 pounds of fat-free mass.

Getting adequate sleep also helped control the dieters’ hunger. Average levels of ghrelin did not change when dieters spent 8.5 hours in bed. When they spent 5.5 hours in bed, their ghrelin levels rose over two weeks from 75 ng/L to 84 ng/L.

Higher ghrelin levels have been shown to “reduce energy expenditure, stimulate hunger and food intake, promote retention of fat, and increase hepatic glucose production to support the availability of fuel to glucose dependent tissues,” the authors note. “In our experiment, sleep restriction was accompanied by a similar pattern of increased hunger and … reduced oxidation of fat.”

The tightly controlled circumstances of this study may actually have masked some of sleep’s benefits for dieters, suggested Penev. Study subjects did not have access to extra calories. This may have helped dieters to “stick with their lower-calorie meal plans despite increased hunger in the presence of sleep restriction,” he said.

The message for people trying to lose weight is clear, Penev said. “For the first time, we have evidence that the amount of sleep makes a big difference on the results of dietary interventions. One should not ignore the way they sleep when going on a diet. Obtaining adequate sleep may enhance the beneficial effects of a diet. Not getting enough sleep could defeat the desired effects.”

The National Institutes of Health funded this study. Additional researchers include Dale Schoeller, PhD, of the University of Wisconsin, Madison, WI; plus Jennifer Kilkus, MS, and Jacqueline Imperial, RN, of the University of Chicago’s General Clinical Resource Center; and Arlet Nedeltcheva, MD, at the University of Chicago at the time of the study but now at the U.S. Food and Drug Administration.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Chicago Medical Center. http://www.sciencedaily.com /releases/2010/10/101004211637.htm

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Comments

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  3. ? This information is really good and I will say will always be helpful if we try it risk free… So if you can back it up ? That will really help us all. And this might bring some good repute to you. The diet of human beings prior to the arrival of agriculture, technology and civilization is known as the Paleolithic Diet , This Stone Age diet, in short, consisted of mainly lean red meat and vegetables. In this type of diet animal meat is consumed in large quantities and 45 to 65% of the energy needed by the body is derived from it. Over and over again, life expectancy studies related to diet, including by the World Health Organization (WHO), have concluded that Americans and Europeans would do better to eat more like third world peoples as the options provided by their additional wealth have most often lead to poor nutritional choices. This is the same basis for the USDA based their popular food pyramid in 1992 ? Researchers at Harvard have only suggested perhaps tweaking the food pyramid by replacing some dairy products and read meat with more fruits, vegetables, and fish while also emphasizing the importance of improving the ratio of “good” to “bad” cholesterol.. Plus, exercise not only makes weight loss much easier, but also lowers blood glucose levels, decreases blood pressure, improved circulation, and increases one’s metabolism. Good regular sleep patterns are also just as important. Diets based on USDA recommendations include DASH, American Diabetic Assoc, Weight Watchers, and Jenny Craig? When children understand how important “real food” is and where the natural ingredients of our food come from, they will increase the general population’s appreciation for preserving our natural environment and limiting toxins and polluting processes in our world. We may even trend back to the time when people stepped outside their homes to interact with family and neighbors in home and community gardens and block-party barbeques! Does anybody even remember how nice those days were?

  4. Hello! I just wanted to take the time to make a comment and say I have really enjoyed reading your blog. Thanks for all your work.

  5. While we’re dabbling in the area of Sleep Loss Limits Fat Loss | ASK In Your Face, A recent survey found that more people are sleeping less than six hours a night, and sleep difficulties visit 75% of us at least a few nights per week. A short-lived bout of insomnia is generally nothing to worry about. The bigger concern is chronic sleep loss, which can contribute to health problems such as weight gain, high blood pressure, and a decrease in the immune system’s power.

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