Changes in the Recreational Built Environment and Youth Body Mass Index.

Objective: Many cities have implemented programs to improve the recreational built environment. We evaluated whether neighborhood recreational built environmental changes are associated with change in body mass index (BMI).

Methods: We performed a longitudinal assessment of association between the recreational built environment and BMI percent of 95th percentile (BMIp95). Patient data from 2012 to 2017 were collected from electronic medical records including height, weight, sex, race/ethnicity, insurance type, and address. BMIp95 was calculated. Environmental data including sidewalks, trails, Healthy Mile Trails, and parks were collected. Patients' neighborhood environments were characterized using proximity of features from home address. Multilevel linear regressions with multiple encounters per patient estimated effects of recreational features on BMIp95 and stratified models estimated effect differences.

Results: Of 8282 total patients, 27.7% were non-Hispanic White, half were insured by Medicaid, and 29.5% changed residence. Median BMIp95 was 86.3%. A decrease in BMIp95 was associated with park proximity in the full cohort (-2.85; 95% CI [confidence interval]: -5.47, -0.24; P = .032), children with obesity at baseline (-6.50; 95% CI: -12.36, -0.64; P = .030) and privately insured children (-4.77; 95% CI: -9.14, -0.40; P = .032). Healthy Mile Trails were associated with an increase in BMIp95 among children without obesity (1.00; 95% CI 0.11, 1.89; P = .027) and children living in higher income areas (6.43; 95% CI: 0.23, 12.64; P = .042).

Conclusions: Differences in effect indicate that built environment changes may improve or exacerbate disparities. Improving obesity disparities may require addressing family-level barriers to the use of recreational features in addition to proximity.