Have inequities in BMI widened in a nationally represented cohort of kindergarteners?

Abstract

Objective: The primary objective of this study was to determine if inequities in growth trajectories measured by BMI between white and non-white groups have widened in school-aged children. Methods: Data from the 1998 and 2010 kindergarten cohorts of the Early Longitudinal Childhood Study were analyzed for differences in growth rates by race/ethnicity. Sex-stratified, linear regression models that included a three-way interaction term between race/ethnicity, age, and cohort and controlled for age and socioeconomic status to determined whether inequities have changed significantly over time. Results: Black/African American boys had an overall higher change in BMI per year of 1.04 kg/m2 compared to their white peers (CI:0.08,2.0;p<0.05) in the 2010 cohort. This higher slope in BMI per year was also the case for boys of two or more race/ethnicities [2.9 kg/m2 (CI:1.2,4.6;p<0.001)], Hispanic girls [0.95 kg/m2 (CI:0.3,1.6;p<0.01)], and Native Hawaiian/Pacific Islander girls [5.17 kg/m2 (CI:0.6,9.8;p<0.05)]. Conclusion: Inequities in BMI have widened in multiple non-white race/ethnicity groups of children compared to white children, specifically black/African American boys, boys of two or more race/ethnicities, Hispanic girls and Native Hawaiian/Pacific Islander girls. For other non-white groups, inequities have persisted from the 1998 to the 2010 cohort. Overall, we find that these differences in BMI between white and non-white groups should be cause for public health concern.