Short objective sleep duration was associated with weight regain and attenuated improvements in body composition one year after weight loss, independent of intervention allocation, age, and sex.
Signe S. Torekov, PhD, MSc
Recently published findings from a randomized, controlled, 2-by-2 factorial study showed that short sleep duration and worse sleep quality were associated with less weight loss, indicating that insufficient sleep predicts weight regain during interventional efforts to maintain weight loss.
Led by Signe S. Torekov, PhD, MSc, professor in clinical and translational metabolism, Kobenhavns University, the trial featured 195 adults with obesity who completed an 8-week low-calorie diet and were thus randomly assigned to 1-year weight loss maintenance with or without exercise and liraglutide 3 mg/day or placebo. The wrist-worn GENEActiv accelerometers and the Pittsburgh Sleep Quality Index (PSQI) were used to measure sleep duration and quality before and after initiating the diet.
Participants randomized to exercise were encouraged to attend 2 weekly supervised sessions of 45 min duration along with 2 weekly sessions of 30 min performed individually. The supervised sessions involved interval-based spinning and circuit training. To support weight maintenance after weight loss, all participants attended monthly consultations with weighing and dietetic support in accordance with recommendations from Danish authorities. The cohort of adults were between the ages of 18 and 65 years and had body mass index between 32 and 43 kg/m2.
In total, 166 (85%) participants attended the final assessment of body weight 52 weeks after randomization, for which valid accelerometer data were available for 119 participants and a PSQI global score was available for 161 participants. Prior to the low-carlorie diet, the overall mean sleep duration was 6.07 (±0.83) h/night as measured by accelerometer, mean self-reported sleep duration was 6.60 (±1.05) h/night, and self-reported sleep quality was 6.1 (±3.1), indicating poor sleep quality on average.
Following the 8-week low-calorie diet, investigators observed a mean weight loss of 13.1 kg (95% CI, 12.4-13.7) and a mean decrease in fat percentage of 2.3 points (95% CI, 2.1-2.6). Additionally, self-reported sleep duration increased by 9 min/night, sleep efficiency increased by 2.1%, and PSQI global score decreased by –0.8 (95% CI, –1.2 to –4.0), indicating improved sleep quality.
At randomization, immediately after the diet-induced weight loss, 48 participants were identified with short sleep duration, defined as accelerometer-measured mean sleep duration of less than 6 h/night, with the remaining 111 having more than 6 h/night, considered normal sleep. At the 52-week weight maintenance phase, short sleepers regained body weight whereas normal sleepers maintained weight loss. Linear regression analyses showed that for each hour increase in mean sleep duration following weight loss, the change in body weight after 52 weeks was –1.7 kg (P = .073) while change in body fat percentage was –0.80 points (P = .026).
On PSQI, between poor sleepers (mean PSQI global score of 8.2; n = 73) and good sleepers (mean PSQI global score of 3.3; n = 114), the difference in weight change during weight maintenance was 1.5 kg (P = .27) and fat percentage by 0.1 percentage points (P = .91) in favor of the good quality sleepers. A worse global PSQI score after diet-induced weight loss tended to be associated with weight regain (P = .052) and increased fat percentage (P = .087) during weight maintenance.
Findings also showed that good quality sleepers identified before the low-calorie diet had a larger decrease in body weight (–3.5 kg; P = .010) and body fat percentage (–1.3 percentage points; P = .018) during the study period as a whole compared with poor quality sleepers. Additionally, when assessing the effects of weight loss maintenance with exercise on sleep, investigators observed that exercise groups had maintained self-reported sleep quality increments attained from the low-calorie diet at week 52, whereas the non-exercise groups relapsed. Factors that improved with exercise as compared with controls were daily disturbances (P <.001) and perceived sleep quality (P = .05).