Rural-Urban Disparities in Obesity Prevalence Among Working Age Adults in the United States: Exploring the Mechanisms.

PURPOSE: Higher prevalence rates of overweight and obesity in rural America have been consistently reported, but sources of these disparities are not well known. This study presented patterns and mechanisms of these disparities among working age Americans.

DESIGN: Cross-sectional study.

SETTING: United States of America.

PARTICIPANTS: The study included 10 302 participants of the 2003-2008 National Health and Nutrition Examination Survey (NHANES) who were 20 to 64 years old, not pregnant, and with a body mass index ranging from 18.5 to 60.

MEASURES: Individual-level data were from NHANES including age, gender, race/ethnicity, immigrant status, education, and family income. The outcomes were prevalence of obesity and prevalence of overweight and obesity combined. Neighborhood data were constructed from the 2000 US Census providing tract-level information on family median income and built environmental features and from the 2006 ESRI ArcGIS 9.3 Data DVD providing tract-level park location information.

ANALYSIS: Geographic information system (GIS) methods were used to create a measure of spatial distance to local parks capturing park accessibility. Random intercept logistic and ordinal logit regression analyses were performed.

FINDINGS: Multivariate regression results showed that the odds of obesity was higher in rural areas compared to urban areas (odds ratio = 1.358, P < .001) net of demographic controls and that this gap was largely attributable to individual educational attainment and neighborhood median household income and neighborhood built environmental features. After controlling for these hypothesized mediators, the elevated odds associated with rural residence was reduced by nearly 94% and rendered statistically insignificant.

CONCLUSIONS: In this nationally representative cross-sectional sample, rural-urban obesity disparities were large and explained by rural-urban educational differences at the individual level and economic and built environmental differences at the neighborhood level.