Dropping excess pounds may not only improve your physical health, it might also help you feel more awake and happy, a new study shows.
The research, presented this week at the joint meeting of the International Society of Endocrinology and the Endocrine Society in Chicago, included 390 obese women and men who were assigned to one of three programs meant to help them lose weight through diet and exercise.
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One group received usual care, in which they were given printed educational materials during visits every three months with their primary care provider. The second group saw their primary care provider every three months, and also had brief meetings with lifestyle coaches. The third group met with their primary care providers and lifestyle coaches, and also received meal replacements and weight-loss medications.
Changes in the participants' weight, amount and quality of sleep and mood were assessed after six and 24 months. The average weight loss in the usual care group was 4.4 pounds, compared with about 8 pounds in the second group and close to 15 pounds in the third group.
However, no matter which group they were in, participants who lost at least 5 percent of their weight after six months slept an average of nearly 22 minutes more each night than they had before, the study found.
People who lost less than that gained only about one more minute of sleep a night, the researchers added.
Those who lost at least 5 percent of their weight also had greater improvements in the quality of their sleep, as well as their overall mood, compared to those who lost less weight, the study found.
Not all of the benefits were sustained over time, however: After two years, only improvements in mood remained statistically significant for patients.
"This study confirms several studies reporting that weight loss is associated with increased sleep duration," lead investigator Dr. Nasreen Alfaris, a fellow in the department of medicine at the Perelman School of Medicine at the University of Pennsylvania, said in an Endocrine Society news release.
She believes more research is needed to see whether gaining back the lost weight might reverse the benefits to sleep and mood.
Experts note that findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
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