Association between body mass index and individual characteristics and the school context: a multilevel study with Portuguese children

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.

Inter-individual variability in children's physical growth and body composition: Findings of longitudinal ELOS-Pré study

BACKGROUND

Children's physical growth (PG) and body composition (BC) can be influenced by birth weight and type of delivery.

AIM

To longitudinally analyze the dynamics of PG and BC of children from 5 to 9 years; to investigate the inter-individual differences according to age, sex, BW, and type of delivery across the following years of the study.

SUBJECTS AND METHODS

A total of 1236 children (597 boys) were evaluated at 5-years of age and followed annually until 9-years. PG and BC measurements were evaluated. Multilevel modeling was used.

RESULTS

Annual increments were observed (p < .001). Girls presented lower height and fat-free-mass but higher %BF (p < .001). Distinct trajectories between the sexes were observed for height (p < .001). Low-birth-weight children presented lower height, body mass, and fat-free-mass (p < .001), but the interaction between velocity of growth and BC was significant only in height (p < .05). Children born by had lower height, body mass, and %BF, and gained less body mass per year than those born by vaginal delivery (p < .05). Significant inter-individual differences were observed at 5-years of age and in their trajectories, except for fat-free-mass (p < .01).

CONCLUSION

There are differences in the dynamics of PG and BC, low-birth-weight and type of delivery influence the dynamics of PG during this interval of ages.