Getting regular, uninterrupted sleep might help those who are trying to lose weight, according to a new, small-scale study.
The preliminary research was presented this week at the American Heart Association’s Epidemiology, Prevention, Lifestyle & Cardiometabolic Health Scientific Sessions 2023 in Boston.
In the study, researchers looked at 125 adults who were enrolled in a year-long weight-loss program, and measured their sleep habits to see if there was any correlation between maintaining a healthy sleep schedule and meeting their weight goals.
“Focusing on obtaining good sleep — seven to nine hours at night with a regular wake time, along with waking refreshed and being alert throughout the day — may be an important behaviour that helps people stick with their physical activity and dietary modification goals,” Christopher E. Kline, Ph.D., an associate professor in the department of health and human development at the University of Pittsburgh, said in a news release. “A previous study of ours reported that better sleep health was associated with a significantly greater loss of body weight and fat among participants in a year-long, behavioural weight loss program.”
The vast majority of the participants were women, comprising 91 per cent of the sample, and the average age was 50 years old.
Sleep habits were measured at the beginning of the program, the halfway mark of six months, and finally at 12 months. Participants filled out patient questionnaires and a sleep diary, but sleep data was also recorded in seven day stretches, during in which participants wore a device around their wrist that recorded their sleep and their waking activity.
The quality of their sleep was scored as “good” or “poor” on regularity, satisfaction, alertness, timing, duration and efficiency – meaning the percentage of time spent in bed where the participant was actually asleep.
In order to contrast sleep with the participant’s progress in the weight loss program, researchers looked at the percentage of group sessions that each participant attended, the percentage of days in which the participants reported meeting their dietary goals, and the changes in their duration of moderate to vigorous physical activity.
Researchers adjusted for sex, age, race and whether the participant was sharing a bed with a partner, which can impact sleep quality.
After controlling for these factors, researchers found that better sleep health was associated with a higher rate of attendance in group sessions, closer adherence to caloric intake goals and participants’ physical exercise duration increasing over time.
Essentially, those who got a better night’s sleep may have been more energized to exercise and to attend sessions to meet their goals, the research suggests.
There was a drop in participants’ engagement with the program across the board in the latter six months of the program, which researchers say is common with these programs, but the pattern still persisted.
“There are over 100 studies linking sleep to weight gain and obesity, but this was a great example showing how sleep isn’t just tied to weight itself, it’s tied to the things we’re doing to help manage our own weight,” Michael A. Grandner, director of the Sleep and Heath Research Program at the University of Arizona, said in the release.
“Studies like this really go to show that all of these things are connected, and sometimes sleep is the thing that we can start taking control over that can help open doors to other avenues of health.”
The study is limited by its size and lack of diversity among participants, as well as the fact that most participants had relatively good sleep health at the beginning of the program. To get results that can be applied more broadly, more research is needed.
“It remains unclear whether it would be best to optimize sleep prior to, rather than during, attempted weight loss,” Kline said. “In other words, should clinicians tell their patients to focus on getting better and more regular sleep before they begin to attempt weight loss, or should they try to improve their sleep while at the same time modifying their diet and activity levels?”