Stress affects sleep, mood and body weight: Study

By Dr. Ananya Mandal, MDMar 29 2011

In a new study appearing in the International Journal of Obesity, researchers have found that stress may affect sleep, mood and ultimately body weight. The study found that people with high stress and poor sleep were less likely to achieve a 10-lb. weight loss goal.

The study, led by Dr. Charles Elder of the Kaiser Permanente Center for Health Research in Portland, Ore., involved 472 obese adults (with BMIs between 30 and 50) over age 30. Of these 83% were women and a quarter were senior citizens over 65. The participants were included in a weight-loss program that included attending weekly group counseling sessions, keeping a food diary, exercising at moderate intensity most days of the week (for at least three hours per week), reducing daily consumption by 500 calories and sticking to a low-fat, low-salt diet high in fruits, veggies, whole grains and lean proteins. At the beginning of the study and again six months later, the researchers looked at certain lifestyle measures, like the participants' stress levels, nightly sleep quality, and depression.

Results showed 60% of participants lost at least 10 lbs. As expected, researchers found that factors like exercise, keeping a food diary and attending behavioral counseling sessions were highly correlated with successful weight loss. On average, participants lost nearly 14 lbs.

But the researchers also found some other influential predictors of success: sleep quality and stress. Participants who reported sleeping less than 6 hours, or more than 8 hours, per night at the start of the study were less likely to meet the 10-lb. weight loss goal, compared with people who slept 6-8 hours. Those that reported high levels of stress were only half as likely to make it to the second phase of the study as people who got 6-8 hours of sleep and had low stress. “Clinicians and investigators might consider targeting sleep, depression and stress as part of a behavioral weight loss intervention,” the authors concluded.

“This study suggests that when people are trying to lose weight, they should try to get the right amount of sleep and reduce their stress…Some people may just need to cut back on their schedules and get to bed earlier. Others may find that exercise can reduce stress and help them sleep. For some people, mind/body techniques such as meditation also might be helpful,” said the study's lead author, Dr. Charles Elder

In the last week’s American Heart Association meeting, researchers from Columbia University released data from a study of 26 healthy men and women, showing that when people are sleep-deprived (4 hours of sleep a night for six nights), they eat significantly more calories than when they're well rested (9 hours of sleep a night for six nights). In the study, sleep-deprived women ate 329 more calories per day, and men ate 263 more calories - and most of those excess calories came from foods like ice cream and fast food.

Researchers speculate that disruptions to the sleep cycle stimulate a hormone called ghrelin, which in turn stimulates appetite. Also chronic stress can trigger overeating as a coping behavior.

The study authors as well as experts recommend cutting down to 500 calories a day to lose 0.5 to two pounds each week, eating a low-fat diet rich in fruits, vegetables and whole grains and adding exercise time to reach 30 to 60 minutes every day and at least 180 minutes a week. A holistic view of health that considers diet, exercise, smoking, sleep, and controlling stress is important, said Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine in New Haven, Conn. “Anyone who has ever tried to lose weight probably could have said much the same from personal experience. Similarly, weight loss reduced stress and depression. This, too, is suggested by sense and common experience, as it is affirmed by the science reported here,” Katz said.

A second part of the study is now looking at how the participants maintained their weight loss for another six months. The study was funded by the U.S. National Institutes of Health's National Center for Complementary and Alternative Medicine.