MAASTRICHT, Netherlands — Poor sleep may be keeping you from reaching your weight loss goals, a new study suggests. Researchers from the University of Copenhagen say that dieters are more likely to experience weight gain if they don’t get enough sleep.
However, study authors also found that two hours of vigorous exercise a week boosts sleep quality.
“It was surprising to see how losing weight in adults with obesity improved sleep duration and quality in such a short time, and how exercising while attempting to keep the weight off preserved improvements in sleep quality,” says lead author Adrian Bogh in a media release.
“Also, it was intriguing that adults who aren’t sleeping enough or getting poor quality sleep after weight loss appear less successful at maintaining weight loss than those with sufficient sleep.”
Previous studies have shown that poor sleep can increase the risk of high blood pressure, high cholesterol, and hardening of the arteries. Sleep deprivation also contributes to obesity, diabetes, and inflammation — all of which can worsen cardiovascular disease, the world’s number one cause of death.
The latest findings add to evidence that poor sleep is also a key reason why many people regain weight after losing it. The results come from an analysis of data from a study called S-Lite involving 195 obese individuals in Denmark with BMIs (body mass indexes) ranging from 32 to 43.
The weight comes back without exercise
Participants followed a very low-calorie diet (800 kcal/day) for eight weeks and lost an average of 12 percent of their body weight. Researchers randomly assigned the group to participate in four exercise sessions a week, take a daily weight loss drug, take a placebo, or a combination of both. Scientists then tracked the participants for a year.
The exercisers had supervised 45-minute sessions, twice a week, doing spinning and circuit training, and two unsupervised sessions of 30 minutes. Researchers measured sleep duration using data from accelerometers worn before and after the diet and at 13, 26, and 52 weeks during follow-up.
The participants also assessed sleep quality with a self-rated questionnaire, with scores ranging from 0 for the best to 21 for the worst. Any score over five is considered poor.
Study authors grouped the dieters according to their average sleep duration (below or above six hours per night) or sleep quality (below or above a score of five) to identify associations with weight gain. Results show sleep quality and duration improved in all participants after the diet. However, after a year the exercise group maintained the benefits while the others relapsed by an average of one point.
6 hours of sleep is key to keeping off unwanted weight
The study also showed those who slept on average less than six hours per night at the start increased their BMI by 1.3 compared to their peers getting more rest. The weight loss drug Liraglutide had no significant effect on sleep compared to the placebo. Similarly, the BMIs of poor sleepers with a score of five or higher went up by 1.2 compared to good sleepers.
“The fact that sleep health was so strongly related to weight loss maintenance is important since many of us don’t get the recommended amount of sleep needed for optimal health and functioning,” concludes study co-author Professor Signe Torekov.
“Future research examining possible ways of improving sleep in adults with obesity will be an important next step to limit weight regain. Weight loss maintained with exercise seems promising in improving sleep.”
The researchers presented their findings at the European Congress on Obesity in Maastricht in The Netherlands.
South West News Service writer Mark Waghorn contributed to this report.