2023 Volume 10 Issue 1 Pages 39-49
Objectives: The aim of this study was to elucidate the effects of sleep habits on obesity in Japan.
Methods: We analyzed data from healthy people who underwent the “Ningen Dock” examination between 2012 and 2020. A total of 5,518 subjects (age: 57.5±13.1 years) were included in a cross-sectional analysis, and 1,515 (age: 58.2±11.9 years) were followed for 6 years in a longitudinal analysis.
Results: The mean sleep duration was 6.4±1.0 hours and was significantly longer in young and elderly people than in middle-aged people. Obesity prevalence was 25.6%, and 11.5% had obesity onset during the follow-up period. In both univariate and cross-sectional multivariate analyses, sleep was significantly associated with obesity. Other significant factors were age, current smoking in males, and habitual drinking and exercise in females. Compared to the 6-hour group, the odds ratio for obesity was significantly higher in males in the <6-hour sleep group and lower in the 7-hour and ≥8-hour groups. In females, there were tendencies towards higher obesity rates in the <6-hour group, and lower rates in the 7-hour group. In the longitudinal multivariate analysis, the odds ratio for sleep in relation to obesity onset tended to be higher in the <6-hour group and lower in the 7-hour group.
Conclusions: Short sleep duration was significantly correlated with obesity in males, and a similar tendency was found in females. Therefore, a sleep duration of approximately 7 hours may be advantageous in terms of obesity prevention in adults.
