Sleep gets better as waistlines shrink

JOHNS HOPKINS (US) — Losing weight helps overweight and obese people sleep better, a study shows.

The improvement in problems like fatigue, insomnia, sleep apnea, and restlessness occurs whether the patient sheds pounds through diet and exercise or through dietary changes alone, the researchers found.

“We found that improvement in sleep quality was significantly associated with overall weight loss, especially belly fat,” says Kerry Stewart, professor of medicine and director of clinical and research exercise physiology at the Johns Hopkins University School of Medicine.


Stewart is the senior author of the study, which was presented November 6 at the American Heart Association Scientific Sessions by lead author Soohyun Nam, now at the Yale University School of Nursing.

The study involved 77 overweight or obese people with either type 2 diabetes or pre-diabetes. The participants were randomly split into two groups. One group went on a weight-loss diet and had supervised exercise training, while the other only had the diet. A total of 55 participants completed the six-month study.

The participants filled out a survey at the beginning and end of the study to identify sleep problems, including sleep apnea, daytime fatigue, insomnia, restless sleep, excessive sleep or sleepiness, and use of sedatives to aid sleep. Body mass index and abdominal fat were also measured at the start and end of the study.

Both groups lost about 15 pounds, on average. They also lost about the same amount of belly fat, about 15 percent.

Although the participants reported a variety of sleep problems, no issue stood out as being the most common, so the researchers analyzed a composite score, which reflects overall sleep health. What they found was that both groups improved their overall sleep score by about 20 percent with no differences between the groups.

“The key ingredient for improved sleep quality from our study was a reduction in overall body fat, and, in particular belly fat, which was true no matter the age or gender of the participants or whether the weight loss came from diet alone or diet plus exercise,” says Stewart.

Good sleep quality is important in general for good physical and mental health, as well as for a healthy cardiovascular system, notes Stewart. Depending on the cause, chronic sleep disruptions increase the risk of high blood pressure, heart attack, stroke, and irregular heartbeats. Obesity increases the risk of sleep problems.

The study was funded by the National Heart, Lung, and Blood Institute and the National Center for Advancing Translational Sciences.

Source: Johns Hopkins University