A Large Prospective Investigation of Sleep Duration, Weight Change, and Obesity in the NIH-AARP Diet and Health Study Cohort

The relationship between sleep and obesity or weight gain in adults, particularly older populations, remains unclear. In a cohort of 83,377 US men and women aged 5172 years, we prospectively investigated the association between self-reported sleep duration and weight change over an average of 7.5 years of follow-up (19952004). Participants were free of cancer, heart disease, and stroke at baseline and throughout the follow-up. We observed an inverse association between sleep duration per night and weight gain in both men (P for trend 0.02) and women (P for trend 0.001). Compared with 78 hours of sleep, shorter sleep (5 hours or 56 hours) was associated with more weight gain (in kilograms; men: for 5 hours, 0.66, 95 confidence interval (CI): 0.19, 1.13, and for 56 hours, 0.12, 95 CI: 0.02, 0.26; women: for 5 hours, 0.43, 95 CI: 0.00, 0.86, and for 56 hours, 0.23, 95 CI: 0.08, 0.37). Among men and women who were not obese at baseline, participants who reported less than 5 hours of sleep per night had an approximately 40 higher risk of developing obesity than did those who reported 78 hours of sleep (for men, odds ratio 1.45, 95 CI: 1.06, 1.99; for women, odds ratio 1.37, 95 CI: 1.04, 1.79). The association between short sleep and excess weight gain was generally consistent across different categories of age, educational level, smoking status, baseline body mass index, and physical activity level.