title: Television, sleep, outdoor play and BMI in young children: the GECKO Drenthe cohort.
abstract: In this study, we investigated the interplay between screen time, sleep duration, outdoor play, having a television in the bedroom and the number of televisions at home and their association with body mass index (BMI) in preschool children. All participants, 3-4 years of age (n = 759), were part of the Groningen expert center for kids with obesity (GECKO) Drenthe birth cohort. Weight and height were measured. Total screen time, number of televisions at home, a television in the bedroom, sleep duration and time of outdoor play were self-reported by parents in a questionnaire. Ordinary least square (OLS) regression-based path analysis was used to estimate direct and indirect effects on BMI in mediation models. A television in the bedroom or more televisions at home gave a higher screen time, which were associated with decreased sleep duration and resulted in higher BMI (indirect effect = 0.0115, 95% bootstrap interval = 0.0016; 0.0368 and indirect effect = 0.0026, 95% bootstrap interval = 0.0004; 0.0078, respectively). In contrast to the direct effect of screen time, sleep duration and a television in the bedroom on BMI, no direct effect was found for outdoor play and number or televisions at home on BMI.
  
  
  CONCLUSIONS
  Short sleep duration, long screen time and a television in the bedroom were associated with the presence of overweight in preschool children.
authors.affiliation: Department of Epidemiology (FA40), University of Groningen, University Medical Center Groningen, P.O. Box 30.001, 9700 RG, Groningen, The Netherlands, a.sijtsma@umcg.nl.
authors.forename: Anna
authors.initials: A
authors.lastname: Sijtsma
authors.forename: Marjory
authors.initials: M
authors.lastname: Koller
authors.forename: Pieter J J
authors.initials: PJ
authors.lastname: Sauer
authors.forename: Eva
authors.initials: E
authors.lastname: Corpeleijn
mesh_terms: D015992:Body Mass Index; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D050177:Overweight; D057185:Sedentary Behavior; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires; D013690:Television