. Author manuscript; available in PMC: 2009 Aug 7.

Published in final edited form as: Obesity (Silver Spring). 2008 Jan 17;16(3):643–653. doi: 10.1038/oby.2007.118

Table 3.

Prospective cohort studies of sleep duration and weight.

Author Country Year Follow-up Time	Sample Size	Baseline Age	Population source	Measure of weight	Measure of Sleep	Potential Confounders Addressed	Cross-sectional Relationship	Longitudinal Relationship
Agras³⁷ USA 2004 6.5 years	150	3	Birth cohort from San Francisco	Measured BMI	1 sleep question to parents each year over 3 years	Age, ethnicity, SES, physical activity, TV viewing, diet, breastfeeding, eating behaviors, birthweight, parental obesity, parental attitudes towards eating and weight, temperatment, parental age	Not assessed.	Short SD associated with increased overweight risk.
Hasler³⁸ Switzerland 2004 13 years	496	27	Zurich Cohort Study	Reported BMI	3 sleep questions (bedtime, wake-time, and sleep latency) at 4 time points	Age, sex, smoking, SES, physical activity, eating behaviors, parental obesity, depression	Short SD associated with increased obesity risk.	Short SD associated with increased obesity risk.
Gangwisch⁶ USA 2005 9 years	9,588	32–86	NHANES	Measured & reported BMI	1 sleep question	Age, sex, ethnicity, smoking, alcohol, SES, physical activity, depression, insomnia, sleepiness	U-shaped association between SD and obesity risk.	Short SD associated with increased obesity risk.
Reilly³⁶ UK 2005 4 years	8,234	3	ALSPAC	Measured BMI	1 sleep question to parents	Age, sex, maternal smoking, SES, TV viewing, diet, birthweight, parental obesity	Not assessed.	Short SD associated with increased obesity risk.
Patel³ USA 2006 16 years	68,183	45–65	Nurses Health Study	Reported BMI	1 sleep question	Age, sex, smoking, alcohol, caffeine, SES, physical activity, diet, medical disorders, OSA, shiftwork, menopause, medications	U-shaped association between SD and obesity risk.	Short SD associated with increased obesity and weight gain risk.

All estimates provided with 95% confidence intervals in parentheses. BMI: body mass index; SD: sleep duration; OR: odds ratio; HR: hazard ratio; NHANES: National Health and Nutrition Examination Survey; ALSPAC: Avon Longitudinal Study of Parents and Children; SES: socioeconomic status; TV: television; OSA: obstructive sleep apnea.