Adults with obesity who lost weight while dieting struggled to maintain their weight loss if they slept less than 6 hours per night, according to findings presented at the European Congress on Obesity.

Adrian F. Bogh, a medical student at the University of Copenhagen, and colleagues also found that exercise during weight loss maintenance may help preserve sleep quality but not duration.

In a randomized, placebo-controlled, two-by-two factorial study, Bogh and colleagues evaluated 195 adults with obesity (BMI, 32 to 43 kg/m²). During an 8-week, low-calorie diet period, the participants lost an average of 12% body weight. The participants were then randomly assigned to 1 year of weight loss maintenance with placebo; exercise (4 times per week) and placebo; Saxenda 3 mg (liraglutide, Novo Nordisk) daily; or exercise and liraglutide.

The researchers measured participants’ sleep duration and efficiency with accelerometers and the Pittsburgh Sleep Quality Index (PSQI) before the diet period, after the diet period (baseline) and after 26 and 52 weeks of maintenance. A global score of five or more on the PSQI was considered poor sleep and less than five was good sleep.

Overall, sleep quality, efficiency and duration increased for all participants after the diet period. However, participants who got less than 6 hours of sleep per night at baseline increased their BMI by an average of 1.3 kg/m² (P = .02) by week 52 compared with participants who slept 6 to 7 hours each night, according to Bogh and colleagues. Moreover, poor sleepers at baseline increased their BMI by 1.2 kg/m² (P = .01) compared with good sleepers.

Participants who were randomly assigned to some or only exercise maintenance achieved sustained sleep quality improvements from diet by one global score point (P = .02), the researchers reported. Maintenance with liraglutide had no significant effect on any sleep measure.

“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 of preserved improvements in sleep quality,” Bogh said in a press 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.”

Signe S. Torekov, MSc, PhD, a professor in the department of biomedical sciences at the University of Copenhagen, added that the findings demonstrate the importance of sleep “since many of us don’t get the recommended amount of sleep needed for optimal health and functioning.”

“Future research examining possible ways of improving sleep in adults with obesity will be an important next step to limit weight regain,” she said. “Weight loss maintained with exercise seems promising in improving sleep.”

References:

Bogh A, et al. Presentation PO3.26. Presented at: European Congress on Obesity; May 4-7, 2022; Maastricht, Netherlands.