Food desert or mirage: Obesity prevalence in preschool-aged children and the neighborhood environment in extremely low-income census tracts of Los Angeles County

Studies have reported differences in obesity risk and food environments by neighborhood income. However, few studies have investigated these relationships in only low-income neighborhoods. Do extremely low-income neighborhoods differ from low-income neighborhoods that are less deprived? Data on low-income preschool-aged children who participated in the WIC program in Los Angeles County in 2009 was used to determine if child obesity rates and number and type of food stores differ between very low-income (defined as having a median household income in the lowest 25th percentile of the study population tracts, <$5,095 per year) and low-income census tracts (having a median household income between $25,095 and $67,321 per year). Income of WIC families, expressed as a percent of the Federal Poverty Level, averaged 57.1% in very low-income tracts and 63.8% in low-income tracts. Preliminary analysis indicates an inverse relationship between child obesity rates and neighborhood median income (p<0.001) in this study population; the child obesity rate in very low-income tracts was 21.3% compared to 18.3% in low-income tracts. A similar percentage of very low- and low-income neighborhoods had one or more supermarkets. However, very low-income tracts were more likely to have independent grocery stores than low-income tracts (88% versus 59%, respectively) and less likely to have chain convenience stores (2.0% versus 11.7%, respectively). Future steps will include an investigation of the mechanisms which may influence the observed disparity in obesity rates of preschool aged children living in low-income neighborhoods.