Investigating the relationship between built environment characteristics and obesity among primary school children in selected urban areas of Tehran

Abstract The evidence on the relationship between built environment factors and obesity in primary school children is limited, and this study is the first to investigate this relationship in Iran. This study utilizes Geographical Information Systems (GIS) techniques to assess built environment indices for geographical addresses based on the street network. A school-based survey was conducted in ten neighborhoods in Tehran from January to April 2019, collecting socio-demographic information and home addresses from 2,677 primary school children (6–13 years). School nutrition experts measured children's height and weight, and their obesity status was calculated based on the BMI z-score adjusted for age and gender. Logistic regression analysis showed that higher accessibility to parks within 2 km was associated with lower odds of obesity, even after adjusting for age, gender, family income, and parental educational level in the model (OR = 0.919, 95% CI = 0.848–0.996). Living in an area less than 400 m from a park was also associated with lower odds of obesity (OR = 0.811, 95% CI = 0.665–0.989). Access to sports facilities and the percentage of major streets were inversely associated with childhood obesity (highest vs. lowest tertile OR = 0.766; 95% CI = 0.597, 0.985 and OR = 0.739, 95% CI = 0.582, 0.938 respectively). However, no significant relationships were identified for residential density, intersection density, land-use diversity, and the effective walkable area index. Similar to findings from other international studies, these results suggest that addressing spatial disparities in access to parks and sports facilities as an amenable environmental factor is important for reducing children's obesity. This information is valuable for creating local policies and intervention programs. Further investigations with a longitudinal design may provide a better understanding of these relationships.