Sleep and Your Weight: Interesting New Research

It’s 2 am and you are wide awake. You’re overworked, stressed and are being pulled in too many directions. And this economy is making things even worse!  You’re lucky if you can clock in 5 hours of sleep a night. And now, despite being careful with your diet, the scale isn’t budging.  What is going on?

You may or may not have heard about the relationship between lack of sleep and increased risk of obesity (as well as heart disease and diabetes). More and more research is showing how your snooze habits affect your weight. Here is the newest study on sleep and your weight:

Sunday, May 17, 2009
Sleep May Be Factor in Weight Control: New Research
Newswise — Could sleep be a critical component to maintaining a healthy body weight? According to new research to be presented on Sunday, May 17, at the American Thoracic Society’s 105th International Conference in San Diego, body mass index (BMI) is linked to length and quality of sleep in a surprisingly consistent fashion.

As part of the Integrative Cardiac Health Project at Walter Reed Army Medical Center, researchers analyzed the sleep, activity and energy expenditures of 14 nurses who had volunteered for a heart-health program at the Walter Reed, where the nurses were employed. The program included nutritional counseling, exercise training, stress management and sleep improvement.

Each participant wore an actigraphy armband that measured total activity, body temperature, body position and other indices of activity and rest.

“When we analyzed our data by splitting our subjects into ‘short sleepers’ and ‘long sleepers,’ we found that short sleepers tended to have a higher BMI, 28.3 kg/m2, compared to long sleepers, who had an average BMI of 24.5. Short sleepers also had lower sleep efficiency, experienced as greater difficulty getting to sleep and staying asleep,” said lead investigator Arn Eliasson, M.D.

Surprisingly, overweight individuals tended to be more active than their normal weight counterparts, taking significantly more steps than normal weight individuals: 14,000 compared to 11,300, a nearly 25 percent difference, and expending nearly 1,000 more calories a day—3,064 versus 2,080.

However, those additional energy expenditures did not manifest in reduced weight.
“We found so many interesting links in our data. It opens up a number of possibilities for future investigation,” said Dr. Eliasson. “Primarily, we want to know what is driving the weight differences, and why sleep and weight appear to be connected.”

He postulates that getting less sleep might disrupt natural hormonal balances—for example, reducing the amount of leptin, otherwise known as the satiety hormone—and could thereby cause those individuals to eat more. Stress may also play a role in both reducing the length and quality of sleep and increasing eating and other behaviors that may result in weight gain.

“Higher perceived stress may erode sleep. Stress and being less rested may cause these individuals to be less organized than normal weight individuals, meaning they would have to make more trips and take more steps to accomplish the same tasks. This might add to their stress and encourage other unhealthy behaviors like stress eating,” said Dr. Eliasson.

“It would be fascinating to know the results of a carefully designed study that controlled for the many influences on weight gain, while varying sleep parameters and measuring hormonal mediators of appetite and metabolism,” said Dr. Eliasson. “We are planning further studies to evaluate the role of stress in sleep and metabolism.” 

My thoughts:
1. I found it interesting that the group of nurses who got less sleep but were more active  (burned off an extra 1000 calories a day!) than the other group, actually weighed more.  You would think that burning off an extra 1000 calories a day would make them leaner than the group that was less active. Sleep seems to play a major role in weight control.

2. This study didn’t address what the participants ate during the day. It is likely that sleep deprivation caused an increased appetite due to the hormonal imbalance (decreased leptin). This in turn, contributed excess calories and weight gain.

3. Bottom line – make getting adeqate sleep a priority! I will be posting tips on how to improve sleep in the next few weeks.