Table 3.
Summary of findings from studies examining the association between sleep and body mass index (BMI) in adults.
| Authors | Date of study | BMI range | Results | Country |
|---|---|---|---|---|
| Vioque et al, 2000 | 1994 | Mean BMI was 26.3 kg/m2 and 16.0% obese among men; mean BMI was 25.7 kg/m2 and 18.1% were obese among women. | Prevalence of obesity decreases with increasing sleep duration. Prevalence Odds Ratios adjusted for sex, age & population size:
≤6h/day: 1.00 7h/day: 0.70 (95% CI 0.48-1.01) 8h/day: 0.59 (95% CI 0.41-0.84) ≥9h/day: 0.47 (95% CI: 0.30-0.74) |
Spain |
| Shigeta et al, 2001 | 1998-1999 | Mean BMI was 23.4 (SD 3.0) kg/m2 | Odds ratio for obesity for sleeping <6 h/night: 1.98 (95% CI 1.03-3.82) versus sleeping 6 or more hours. | Japan |
| Kripke et al, 2002 | 1982 | not reported | A negative association between BMI & sleep in men; a U-shaped association in women. | US, Cancer Prevention II Study |
| Taheri et al, 2004 | 1995 | BMI Quartiles:
25th = 26.2 kg/m2, 50th = 29.7 kg/m2, 75th = 34.7 kg/m2 |
Average time in bed was associated with BMI in a U-shaped manner where lowest mean BMI was associated with 7.7 h/night. | US |
| Patel et al, 2004 | 1986-2002 | not reported | Sleep duration was associated with BMI in a U-shaped manner where the lowest mean BMI was among those sleeping 7-8 h/night. | US (Nurses Health Study) |
| Cournot et al, 2004 | 1996 | 9.8% were obese | Among women, mean BMI was higher for those reporting 6 hours or less sleep per night versus those reporting more than 6 hours (24.4 vs. 23.4 kg/m2). This difference was not observed among men. | France (VISAT study) |
| Vorona et al, 2005 | not reported | Mean BMI was 30 kg/m2 (SD 6) | Mean total sleep time was significantly shorter in the obese group relative to normal weight. The overweight and severely obese group did not differ from normal weight. | US |
| Singh et al, 2005 | not reported | Mean BMI was 27.2 kg/m2, 24.% obese. | Odds ratio for obesity was 1.7 (95% Ci 1.3-2.3) for < 5 h sleep/night and 1.4 (95% CI 1.1-1.8) for 5-6 h sleep/night relative to 7-8 h sleep/night | US |
| Gangwisch et al, 2005 | 1982-1992 | not reported | Cross-sectional analysis of sleep and obesity risk among 32-49 year olds: OR 2.35 (95% CI 1.36-4.05) for 2-4 h/night; OR 1.60 (95% CI 1.12-2.29) for 5 h/night; OR 1.27 (95% CI 1.01-1.60) for 6 h/night relative to 7 h/night. | US |
| Hasler et al, 2004 | 1978-1999 | Mean BMI was 21.2 (SD 2.5) kg/m2 in 1979 and 23.3 (SD 3.8) kg/m2 in 1999. | Prospective Study. Longitudinal analysis resulted in an odds ratio of 0.50 for sleep duration predicting obesity. | Switzerland |
| Patel et al, 2006 | 1986-2002 | Mean BMI ranged from 24.9 (SD 4.5) to 26.1 (SD 5.5) depending on sleep duration group | Prospecive Study. Those who slept ≤ 5 hours gained 1.14 kg (95% CI: 0.49, 1.79) and those sleeping 6 hours gained 0.71 kg (95% CI: 0.41, 1.00) more than those sleeping 7 hours adjusting for age and baseline BMI. | US |
| Kohatsu et al, 2006 | 1999-2004 | 29.51 (SD 5.79) | Cross-sectional analysis indicated sleep duration was negatively associated with BMI (Beta = −0.42; 95% CI: −0.77 to −0.07) after adjustment for covariates. | Rural US |