title: Sleep duration and body mass index in 0-7-year olds.
abstract: OBJECTIVE
  To determine in children aged 0-7 years (1) cross-sectional relationships between body mass index (BMI) and sleep duration, and whether (2) sleep duration predicts later BMI and/or (3) BMI predicts later sleep duration.
  
  
  METHODS
  Longitudinal Study of Australian Children, Waves 1 and 2.
  
  
  METHODS
  Infants aged 0-1 years (Wave 1), followed at age 2-3 years (Wave 2); children aged 4-5 years (Wave 1), followed at age 6-7 years (Wave 2).
  
  
  METHODS
  BMI, sleep duration by time-use diary, parent-reported sleep problems (none/mild vs moderate/severe).
  
  
  METHODS
  Cross-sectional, ANOVA (sleep duration) and χ(2) (sleep problems); longitudinal, linear regression.
  
  
  RESULTS
  3857 (76%) infants and 3844 (77%) children had BMI and sleep data. At every wave, approximately 15% and 5% of children were overweight and obese, respectively. Obesity was not associated with sleep duration at 0-1, 2-3 or 4-5 years, though obese 6-7-year olds slept approximately 30 min less (p<0.001). Sleep problems were similar across BMI categories at all ages. Wave 1 sleep duration did not predict Wave 2 BMI, nor did Wave 1 BMI predict Wave 2 sleep duration.
  
  
  CONCLUSIONS
  In these large child population cohorts, sleep duration did not predict obesity up to age 6-7 years. Current trials of sleep interventions to prevent or manage obesity in young children may be premature.
authors.affiliation: Centre for Community Child Health, Royal Children's Hospital, Flemington Road, Parkville, Vic 3052, Australia. harriet.hiscock@rch.org.au
authors.forename: Harriet
authors.initials: H
authors.lastname: Hiscock
authors.forename: Katherine
authors.initials: K
authors.lastname: Scalzo
authors.forename: Louise
authors.initials: L
authors.lastname: Canterford
authors.forename: Melissa
authors.initials: M
authors.lastname: Wake
mesh_terms: D000886:Anthropometry / Q000379:methods; D001315:Australia / Q000453:epidemiology; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D050177:Overweight / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D012890:Sleep / Q000502:physiology; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D013997:Time Factors