Does the racial composition of the school environment influence children's body mass index?

Purpose: This study investigates the degree to which the racial composition of the school environment may influence the body mass index (BMI) of children aged 10 to 18 years. This research may be viewed as extending prior work that has found that the prevalence of risk behaviors among nonwhite adolescents is influenced by exposure to white adolescents.

Methods: This research used data from the Survey of Adults and Youth, which was conducted as part of the evaluation of the Robert Wood Johnson Foundation's Urban Health Initiative. The study population for this analysis is comprised of parent and child respondents in the 2004 to 2005 survey wave who lived in one of the five program cities: Baltimore, Detroit, Oakland, Philadelphia, and Richmond. We constructed two-level school random effects models and added school and census tract-level variables that describe the racial composition of the residential community and the school attended.

Results: Black and Hispanic adolescent girls who attend schools with a mostly nonwhite student body have higher BMIs than do their white counterparts. However, black girls in predominately white schools do not have higher BMIs than white girls. Further, black and Hispanic girls whose schoolmates are predominately white have significantly lower BMIs than black and Hispanic girls in schools where fewer than half the students are white. These associations are not found among boys, and are net of a broad variety of individual, household, and group level characteristics.

Conclusions: Our findings suggest that the BMI of minority adolescent girls is influenced by the norms of the social environment.