Potentially modifiable mediators for socioeconomic disparities in childhood obesity in the United States

Objective: The aim of this study was to examine modifiable mediators for socioeconomic disparities in childhood obesity in the United States. Methods: This study used the data of 1,211 mother-child dyads from a US national birth cohort from pregnancy to 6 years post partum. Socioeconomic status was indicated by maternal education (college graduate vs. less) and family income (>185% vs. ≤185% of the poverty line). Single- and multiple-factor mediation analyses were conducted for socioeconomic disparities in childhood obesity at 6 years, adjusting for demographics. Results: The confounder-adjusted relative risk of childhood obesity was 1.79 for low maternal education and 1.42 for low family income. Low-maternal-education-related obesity was individually mediated by maternal preconception BMI (percentage of indirect effect, 8.8%), smoking during pregnancy (7.0%), infant weight gain (14.4%), child sleep duration (11.4%), and TV viewing during weekdays at 6 years (4.9%). Low-family-income-related obesity was mediated by maternal preconception BMI (18.5%), smoking during pregnancy (6.3%), child sleep duration (12.8%), and the home learning environment at 6 years (26.2%). In multiple-mediator analysis, significant mediators together mediated 54.0% of maternal-education-related or 39.4% of family-income-related disparities. Conclusions: Maternal preconception BMI, smoking during pregnancy, infant weight gain, child sleep, TV viewing, and the home learning environment substantially mediated socioeconomic disparities in childhood obesity in the United States.