Association Between Weekend Catch-up Sleep and Lower Body Mass: Population-Based Study

Study Objectives: To determine if weekend catch-up sleep (CUS) impacts body mass index (BMI) in the general population. Methods: A stratified random sample (2156 subjects; age 19-82 years old, 43.0 +/- 14.5; 1183 male) from the general population was evaluated, in 2010, using face-to-face interviews about sociodemographic characteristics, height, weight, habitual sleep duration, and time-in-bed at night on weekdays and weekend, sleep-related profiles, mood and anxiety scales, and comorbid-medical conditions. Weekend CUS was identified when nocturnal sleep extension occurred over the weekend, and this was quantified. Average sleep duration, BMI, and chronotype were determined. The association of BMI with the presence and the amount of weekend CUS was analyzed, independent of average sleep duration, chronotype, and sociodemographic factors. Results: BMI and average sleep duration was 23.0 +/- 3.0 kg/m(2) and 7.3 +/- 1.2 hours, respectively. The weekend CUS group consisted of 932 subjects (43.1%) who slept longer on weekend than weekdays by 1.8 +/- 1.1 hours. Weekend CUS subjects had a significantly lower BMI (22.8 +/- 0.19 kg/m(2)) than the non-CUS (23.1 +/- 0.19 kg/m(2)) group, after adjustment for age, sex, average sleep duration, chronotype, other sociodemographic factors, and anxiety/mood status (p = .01) The relationship between weekend CUS and BMI was dose-dependent (p = 0.02): Every additional hour of weekend CUS was associated with a decrease of 0.12 kg/m(2) in BMI (95% confidence interval, -0.23 to -0.02). Conclusions: Weekend sleep extension may have biological protective effects in preventing sleep-restriction induced or related obesity. The results suggest a simple population-level strategy to minimize effects of sleep loss.