A Longitudinal Study of Income Differences in the Height-BMI Relation among U.S. Children Ages 6 to 14

摘要

Previous work has shown a positive height-obesity association in U.S. children that is more pronounced in those from lower-income families than in those from higher-income families. That work has been limited to cross-sectional analysis. This study evaluates income differentials in the inter-temporal associations between childhood height and obesity in U.S. children ages 6 to 14. Pooled samples of 9,670 female and 10,110 male children from the U.S. Early Childhood Longitudinal StudyKindergarten Cohort (ECLS-K) were evaluated in multilevel mixed effects models. The results indicated a modest height-income interaction such that the concurrent height-obesity association was weaker at higher incomes. This strengthened into adolescence for females and weakened for males. With respect to height growth, for lower-income males, being shorter before the typical start of the growth spurt (approximate to 9years) and experiencing faster later growth (between 11 and 14years) were attributes less strongly associated with subsequent obesity. There were no indicated income interactions with height growth in females.