Does Sleep Help You Lose Weight?

Sleep offers many benefits for both your physical and mental well-being. A wide range of problems have been attributed to lack of sleep such as depressed immune function and decreased mental performance. Research also indicates that a lack of sleep might affect your weight. To reap the benefits of sleep for weight loss, you should get about seven to eight hours of sleep a night.

Effects on Metabolism

Getting only four hours of sleep a night produces negative changes in metabolism, according to a 1999 University of Chicago study. In healthy young men, insufficient sleep significantly impacted their body's metabolization of glucose and increased insulin levels--both of which can influence weight gain. Researchers stated the dysfunction that occurred equaled what you might see in someone already suffering from type 2 diabetes. The volunteers also produced lower levels of thyroid hormone, which can slow down metabolism.

Hormonal Changes

Your hormones influence every process in your body and lack of sleep appears to affect the production of hormones that influence body weight. The aforementioned study found that lack of sleep increased the production of the stress hormone cortisol, which has been linked with weight gain, particularly in the abdominal area. Chicago-based sleep researcher Eve Van Cauter says lack of sleep appears to alter the production of hormones that influence appetite. Gherlin, which stimulates appetite, appears to increase while leptin, which signals feelings of fullness, appears to decrease. A study she conducted in 2004 found that men who slept only four hours a night saw their gherlin levels rise by 28 percent and leptin levels fall by 18 percent.

Unhealthy Food Cravings

The hormonal changes inflicted by lack of sleep might cause you to crave foods linked to weight gain. The participants in Van Cauter's study not only reported feeling hungrier after nights they slept less, they also said they had cravings for foods such as cake, ice cream, candy, pasta and bread. While the latter two might not be as unhealthy as sugar-rich foods, eating too many starchy carbohydrates can lead to excess pounds.

Sleep and Fat Loss

More sleep equals more fat loss, according to a study published in the October 2010 issue of the "Annals of Internal Medicine." Conducted at the University of Chicago, researchers had overweight individuals sleep for 8.5 hours nightly for two weeks, followed by 5.5 hours nightly for two weeks. On average, participants slept for seven hours and 25 minutes and five hours and 14 minutes, respectively. During each session, they ate a diet of 1,425 calories a day. While weight loss in pounds was equal regardless of how much they slept--about 6.6 lbs--fat loss was significantly higher during the period of more sleep 3.1 lbs versus 1.3 lbs. While participants lost the same amount of weight in both instances, the group sleeping less lost more nonfat mass such as muscle. Less muscle will derail weight loss efforts in the long term as it slows your metabolism.