title: Short sleep duration and weight gain: a systematic review.
abstract: OBJECTIVE
  The recent obesity epidemic has been accompanied by a parallel growth in chronic sleep deprivation. Physiologic studies suggest sleep deprivation may influence weight through effects on appetite, physical activity, and/or thermoregulation. This work reviews the literature regarding short sleep duration as an independent risk factor for obesity and weight gain.
  
  
  METHODS
  A literature search was conducted for all articles published between 1966 and January 2007 using the search "sleep" and ("duration" or "hour" or "hours") and ("obesity" or "weight") in the MEDLINE database. Additional references were identified by reviewing bibliographies and contacting experts in the field. Studies reporting the association between sleep duration and at least one measure of weight were included.
  
  
  RESULTS
  Thirty-six publications (31 cross-sectional, 5 prospective, and 0 experimental) were identified. Findings in both cross-sectional and cohort studies of children suggested short sleep duration is strongly and consistently associated with concurrent and future obesity. Results from adult cross-sectional analyses were more mixed with 17 of 23 studies supporting an independent association between short sleep duration and increased weight. In contrast, all three longitudinal studies in adults found a positive association between short sleep duration and future weight. This relationship appeared to wane with age.
  
  
  CONCLUSIONS
  Short sleep duration appears independently associated with weight gain, particularly in younger age groups. However, major study design limitations preclude definitive conclusions. Further research with objective measures of sleep duration, repeated assessments of both sleep and weight, and experimental study designs that manipulate sleep are needed to better define the causal relationship of sleep deprivation on obesity.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University Hospitals Case Medical Center and Case Western Reserve University, Cleveland, OH, USA. srp20@case.edu
authors.forename: Sanjay R
authors.initials: SR
authors.lastname: Patel
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000209:etiology* / Q000503:physiopathology; D050177:Overweight / Q000209:etiology* / Q000503:physiopathology; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012892:Sleep Deprivation / Q000150:complications / Q000503:physiopathology*; D013997:Time Factors; D015430:Weight Gain