title: Inadequate sleep as a risk factor for obesity: analyses of the NHANES I.
abstract: OBJECTIVE
  Sleep deprivation has been hypothesized to contribute toward obesity by decreasing leptin, increasing ghrelin, and compromising insulin sensitivity. This study examines cross-sectional and longitudinal data from a large United States sample to determine whether sleep duration is associated with obesity and weight gain.
  
  
  METHODS
  Longitudinal analyses of the 1982-1984, 1987, and 1992 NHANES I Followup Studies and cross-sectional analysis of the 1982-1984 study.
  
  
  METHODS
  Probability sample of the civilian noninstitutionalized population of the United States.
  
  
  METHODS
  Sample sizes of 9,588 for the cross-sectional analyses, 8,073 for the 1987, and 6,981 for the 1992 longitudinal analyses.
  
  
  RESULTS
  Measured weight in 1982-1984 and self-reported weights in 1987 and 1992. Subjects between the ages of 32 and 49 years with self-reported sleep durations at baseline less than 7 hours had higher average body mass indexes and were more likely to be obese than subjects with sleep durations of 7 hours. Sleep durations over 7 hours were not consistently associated with either an increased or decreased likelihood of obesity in the cross-sectional and longitudinal results. Each additional hour of sleep at baseline was negatively associated with change in body mass index over the follow-up period, but this association was small and statistically insignificant.
  
  
  CONCLUSIONS
  These findings support the hypothesis that sleep duration is associated with obesity in a large longitudinally monitored United States sample. These observations support earlier experimental sleep studies and provide a basis for future studies on weight control interventions that increase the quantity and quality of sleep.
authors.affiliation: Mailman School of Public Health, Department of Epidemiology, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA. jeg64@columbia.edu
authors.forename: James E
authors.initials: JE
authors.lastname: Gangwisch
authors.forename: Dolores
authors.initials: D
authors.lastname: Malaspina
authors.forename: Bernadette
authors.initials: B
authors.lastname: Boden-Albala
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003710:Demography; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D012892:Sleep Deprivation / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires