Elnaz KARAMELİKLİ, Hülya GÜL
Turkish Journal of Public Health - 2026;24(1):286-298
Objective: To examine the association between the density-based and proximity-based measures obesogenic built environments-including restaurants, cafés, grocery stores, and urban parks-around students' homes and schools and BMI categories among middle school students. Method: This cross-sectional study included 905 students aged 9-15 years (grades 5-8). Geographic Information Systems (GIS) were used to geocode residential and school locations and to quantify environmental exposures. Density was assessed by counting venues within 400 m, 800 m, and 1,200 m buffers using both straight-line and network-based walking distances. Proximity was measured as the distance to the nearest venue. Ordinal logistic regression models were used to examine associations with BMI categories. Results: Among participants, 24% were overweight, and 13% were obese. Proximity-based measures were more informative than density-based measures. Greater walking distance to fast-food outlets in the home environment was associated with higher cumulative odds of being in a higher BMI category (OR=1.88 per 1 km increase), whereas no statistically significant association was observed for school-based fast-food proximity. Increased distance to urban parks was also associated with higher odds of overweight and obesity in both home (OR=1.58) and school (OR=2.43) environments. Density-based measures showed no statistically significant associations. Conclusion: Proximity to built environment features, particularly urban parks, appears to be more strongly associated with children's BMI categories than venue density. Simultaneous evaluation of home and school environments may enhance understanding of spatial determinants of childhood obesity.
