Relationships Between Measures of the Physical Activity-Related Built Environment and Excess Weight in Preschoolers: A Retrospective, Population-Level Cohort Study.

Background: The built environment can impact health outcomes. Our purpose was to examine relationships between built environment variables related to physical activity and excess weight in preschoolers. Methods: In this retrospective, population-level study of 4- to 6-year-olds, anthropometric measurements were taken between 2009 and 2017 in Calgary and Edmonton, Alberta, Canada. Based on BMI z-scores (BMIz), children were classified as normal weight (-2 ≤ BMIz <1) or excess weight (BMIz ≥1; overweight and obesity). Physical activity-related built environment variables were calculated (distances to nearest playground, major park, school; street intersection density; number of playgrounds and major parks within an 800 m buffer zone). Binomial logistic regression models estimated associations between physical activity-related built environment variables and excess weight. Results: Our analysis included 140,368 participants (females: n = 69,454; Calgary: n = 84,101). For Calgary, adjusted odds ratios (aORs) showed the odds of excess weight increased 1% for every 100-intersection increase [1.010 (1.006-1.015); p < 0.0001] and 13.6% when there were ≥4 playgrounds (vs. 0 or 1) within an 800 m buffer zone [1.136 (1.037-1.243); p = 0.0059]. For Edmonton, aORs revealed lower odds of excess weight for every 100 m increase in distances between residences to nearest major park [0.991 (0.986-0.996); p = 0.0005] and school [0.992 (0.990-0.995); p < 0.0001]. The odds of excess weight decreased as the number of major parks within the 800 m buffer zone increased from 0 to 1 [0.943 (0.896-0.992); p = 0.023] and from 0 to ≥3 [0.879 (0.773-0.999); p = 0.048]. Conclusion: The physical activity-related built environment was associated with excess weight in preschoolers, although relationships varied between cities that differed demographically and geographically.