Association between the environment for physical activity in public schools and childhood obesity: a view in the light of complex systems.

This article aims to analyse the relationship between physical activity (PA) environment at schools, sex, age, and obesity in children, using a network approach. This is a cross-sectional study, with 1,200 children (8.1±1.0 years old) from eight public schools in the same municipality. Weight and height measurements were assessed to calculate the Body Mass Index (BMI) and classified as healthier weight or overweight. To assess the PA environment at school, a interview with the school´s manager was conducted. The association between the PA environment at school and obesity was tested using a Network Analysis performed on the Jasp software. Positive associations between BMI and Physical Education classes (0.847), physical education teacher (0.349), break duration (0.564), and indoor sports court (0.662) were observed. Negative associations were seen with sex (-0.212) age (-0.387), extracurricular PA (-0.492), and playground (-0.557). Additionally, the centrality indicators highlighted extracurricular PA (1.789) as the variables with the highest betweenness values, and BMI with the highest closeness (2.239) and strength (1.230) values. Extracurricular PA and the presence of playgrounds in school´s environment are associated with healthier weight in low-income children.