Sleep deprivation may cause weight gain

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.

The research conducted in Uppsala University in Sweden found that 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 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.

Although research data is inadequate to prove the link between sleep loss and weight gain, evidence is quite sufficient to suggest it. 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.

Source: http://www.reuters.com/article/2011/05/16/uk-health-sleep-idUSLNE74F02320110516

Kids who get recommended sleep least likely to be obese

Scientists at the University of Chicago and the University of Louisville compared the sleep patterns of 308 children, ages 4-10, with their body mass index, a number that considers height and weight. The children wore special wrist-band devices for a week to track the amount they slept.

Some of the kids had blood work done to look at their glucose, insulin, triglycerides and cholesterol levels, which are markers for the risk of type 2 diabetes and future cardiovascular disease.

The study, out online today in Pediatrics, shows:

•Kids slept an average of eight hours a night. This is far less than the nine or more hours recommended for this age group.

•Kids who slept at least 9½ to 10 hours were the least likely to be obese or to have unhealthy blood work.

•The children who slept the least and had the most irregular sleep schedule (they didn't go to bed at a set time) had a substantially greater risk of being obese and having unhealthy blood work.

•Those who got caught up on sleep on the weekends somewhat reduced their risk of being obese or having unhealthy blood work.

•Obese children were less likely to get caught up on their sleep on the weekends.

"Good sleep routines and sleeping the right amount is the best healthy proposition," says lead author David Gozal, chair of the department of pediatrics at the University of Chicago.

Previous research shows that not getting enough sleep may contribute to weight gain partly because it affects hormones that control hunger and feeling full.

Source: USA today. http://www.usatoday.com/printedition/life/20110124/sleepandweight24_st.art.htm