Those who try to lose weight by monitoring calories and increasing exercise may now have another weapon in their obesity-fighting arsenal — a good night’s sleep. A new European study published in the American Journal of Clinical Nutrition augments existing evidence that sleep deprivation can lead to weight gain, not only by increasing appetite, but also by slowing metabolism. Some American doctors have expressed caution against drawing definitive conclusions, however.
The research conducted in Uppsala University in Sweden suggests that habitually getting sufficient sleep is a helpful aid in the pursuit of weight loss, Reuters reports. Christian Benedict, who led the study, states the investigation found as little as a single night’s sleep deprivation can significantly lower energy expenditure in healthy men. This indicates that sleep plays a prominent role in determining daytime energy production.
Previous research has revealed an association between sleep loss and weight gain and also has found that sleep disorders affect blood levels of stress and hunger hormones. In a quest to determine the exact means by which a lack of sleep affects weight, the team of investigators induced differing degrees of sleep conditions in 14 male college students. They divided the men into three groups, consisting of no sleep, normal sleep and limited sleep. The men were then assessed in regard to alterations in factors such as metabolic rate and amount of food consumed.
The results revealed that as little as a single night of curtailed sleep reduced metabolism the following morning. The energy outlay for activities such as breathing and digestion was lessened by 5 to 20 percent. Higher levels of appetite-regulating hormones and stress hormones were also noted. Even though the appetite hormones were affected, the men did not eat more during the day.
In spite of these findings, experts say the link between sleep loss and weight gain has not been proven. Sanford Auerbach, of the Sleep Disorders Center at the Boston Medical Center, recommends the results of the new study be kept in context, as sleep is a complex condition influenced by other factors. He states that although the study’s results reveal sleep loss produces physiologic changes that could cause obesity, evidence is lacking to conclusively substantiate the proposed link.
Although research data is inadequate to prove the link between sleep loss and weight gain, evidence is quite sufficient to suggest it. According to Dr. Michael Breus of AOL Healthy Living, data collected over the past 50 years reveals an inverse relationship between obesity rates and average sleep time, with the highest obesity percentages found in adults getting the least amount of sleep. Another study cited by Dr. Breus found that women who received seven to eight hours of sleep had the lowest incidence of significant weight gain.
The optimal amount of sleep for adults recommended by The National Sleep Foundation is seven to nine hours every night.