title: A cross-sectional examination of school characteristics associated with overweight and obesity among grade 1 to 4 students.
abstract: BACKGROUND
  Excessive weight gain among youth is an ongoing public health concern. Despite evidence linking both policies and the built environment to adolescent and adult overweight, the association between health policies or the built environment and overweight are often overlooked in research with children. The purpose of this study was to examine if school-based physical activity policies and the built environment surrounding a school are associated with weight status among children.
  
  
  METHODS
  Objectively measured height and weight data were available for 2,331 grade 1 to 4 students (aged 6 to 9 years) attending 30 elementary schools in Ontario, Canada. Student-level data were collected using parent reports and the PLAY-On questionnaire administered to students by study nurses. School-level policy data were collected from school administrators using the Physical Activity Module of the Healthy School Planner tool, and built environment data were provided by the Enhanced Points of Interest data resource. Multi-level logistic regression models were used to examine the school- and student-level characteristics associated with the odds of a student being overweight or obese.
  
  
  RESULTS
  There was significant between-school random variation in the odds of a student being overweight [σ²(μ0) = 0.274(0.106), p < 0.001], but not for being obese [σ²(μ0) = 0.115(0.089)]. If a student attended a school that provided student access to a variety of facilities on and off school grounds during school hours or supported active transportation to and from school, he/she was less likely to overweight than a similar student attending a school without these policies. Characteristics of the built environment were not associated with overweight or obesity among this large cross-sectional sample of children.
  
  
  CONCLUSIONS
  This new evidence suggests that it may be wise to target obesity prevention efforts to schools that do not provide student access to recreation facilities during school hours or schools that do not support active transportation for students. Future research should evaluate if school-based overweight and obesity prevention programming might be improved if interventions selectively targeted the school characteristics that are putting students at the greatest risk.
authors.affiliation: School of Public Health and Health Systems, University of Waterloo, 2000 University Avenue, Waterloo, ON N2L 3G1, Canada. sleather@uwaterloo.ca.
authors.forename: Scott T
authors.initials: ST
authors.lastname: Leatherdale
mesh_terms: D002648:Child; D003430:Cross-Sectional Studies; D004779:Environment Design; D005260:Female; D006291:Health Policy; D006293:Health Promotion; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009765:Obesity / Q000517:prevention & control*; D009864:Ontario; D050177:Overweight; D010290:Parents; D011998:Recreation; D012572:School Health Services; D012574:Schools; D013334:Students / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014186:Transportation