Neighborhood Influences on Obesity Disparities in Early Childhood

Background: Young, low socio-economic status (SES), black and Hispanic children suffer a disproportionate burden of obesity compared to their white peers. Being obese or experiencing unhealthy weight gains over early childhood confers risk of poor future health outcomes and is a critical period for obesity prevention. Neighborhood environments may contribute to energy imbalance and unhealthy weight gain in childhood and these relationships may differ among low-SES, black and Hispanic children. Methods: The goal of this dissertation was to investigate the relationship between the neighborhood environments of low-SES, black and Hispanic children and weight trajectories over early childhood. This was accomplished by systematically reviewing the literature linking neighborhood exposures to cardiovascular disease risk in urban low-SES black and Hispanic children to identify risk factors. Based on this review, two empirical studies were conducted evaluating the influence of neighborhood disadvantage and neighborhood food environments on weight (body-mass index z-score) trajectories from age 2 to 5 years. These studies were conducted in a retrospective cohort of children previously developed from electronic health records at two pediatric clinics in Baltimore, Maryland from 2007-2012. Results: The systematic review evaluated 38 studies (3% of the 1,310 studies identified). The best evidence supported relationships between increased body-mass index (BMI) and living in a high poverty neighborhood or one with ready corner/convenience store access. However, many neighborhood characteristics were not examined across multiple studies and there were inconsistent patterns of association across studies for all neighborhood characteristics studied. The second study found that high neighborhood crime was associated with average decreasing BMI z-score trends compared to low crime. The relationship between neighborhood poverty and BMI z-score trajectories differed by race/ethnicity. In low poverty neighborhoods black children had increasing BMI-z trajectories, but white children had decreasing BMI z-score trajectories compared to peers of their same race/ethnicity living in higher poverty neighborhoods. Neighborhood poverty was not related to BMI z-scores or trajectories in Hispanic children. The third study found that children in neighborhoods with many stores accepting Special Supplemental Nutrition Program for Women, Infants and Children (WIC) benefits had higher BMI z-scores at age 2, but more rapidly decreasing BMI z-score trajectories and lower predicted BMI z-scores by age 6, compared to peers with no or few stores in their neighborhood. No relationship was found between healthy or fast food availability and BMI z-scores or trajectories. Conclusions: The results of this dissertation suggest understudied and complex relationships between neighborhood environments and weight in young, low-SES, black and Hispanic children. Further research is needed to expand upon findings of racial/ethnic differences in the relationship between neighborhood poverty and weight trajectories and of the protective effect of WIC store availability among these sub-populations of children