Abstract PL01-04: Impact of the built environment on obesity.
Authors: Keegan Theresa H.M. , Shariff-Marco Salma , Yang Juan , Gomez Scarlett Lin 
Published: August 2014

The prevalence of overweight and obesity has reached epidemic levels in the United States. This poses a significant public health problem given that obesity is a risk factor for many chronic conditions and certain cancers. With these high levels of overweight/obesity in the United States, researchers have begun to search for neighborhood factors, including the social and built environment, which may influence overweight/obesity. The built environment comprises the physical attributes of a person's surroundings, including the existence and condition of sidewalks and trails for walking and other types of recreation, the spatial configuration of street networks, availability of health-promoting resources, and the number of walkable destinations. The social environment, which is often considered together with the built environment, includes the social and economic aspects of a neighborhood.

The built and social environment could affect body size by shaping opportunities or barriers to physical activity or adherence to dietary recommendations. However, studies assessing the association between the built environment and obesity have produced mixed results among adult samples. Recent reviews have identified two measures of the built environment that have been consistently associated with overweight/obesity outcomes across studies. Obesity/overweight has been found to be more prevalent among residents of counties where increasing sprawl makes it more difficult to walk to destinations, while obesity/overweight has been found to be less prevalent in communities with more mixed land use. However, other measures, including population density, density of fast and other food stores, walkability indices, and the number of recreational facilities have not consistently shown associations with overweight/obesity outcomes. The heterogeneity of findings may be due to different measures and operationalizations of the built environment, the geographic buffers and scales used, or the cross-sectional, observational design of most studies.

Focusing on publicly available databases (e.g., Census) obtained at minimal cost (with the exception of business listing data), we compiled the California Neighborhoods Data System (CNDS), an extensive set of geospatial data to characterize the social and built environment in California. We compiled data available at the census tract or finer level for estimating neighborhood effects. Analyses of the CNDS data have found that built environment characteristics of Census-defined neighborhoods vary by neighborhood socioeconomic status. Utilizing CNDS data linked to study data with individual-level sociodemographic and health-related information, we have not found any specific measures of the built environment to be associated with overweight/obesity after adjusting for a composite measure of neighborhood socioeconomic status, but found associations with this measure of neighborhood socioeconomic status. In our recursive partitioning analyses linking CNDS data with a large cohort study in California, we found that the relationship between neighborhood socioeconomic status and overweight/obesity was not uniform across racial/ethnic groups. Specifically, the probability of being overweight/obese was highest for African-American women, regardless of neighborhood socioeconomic status, while for women of other race/ethnicities, living in lower socioeconomic status neighborhoods was associated with a higher probability of being overweight/obese. Similarly, in women diagnosed with breast cancer in two population-based studies in the San Francisco Bay Area, we found the odds of being overweight/obese to be associated with both African American and Hispanic race/ethnicity and living in a lower socioeconomic status neighborhood. The relationship between neighborhood socioeconomic status and overweight/obesity highlights the importance of socioeconomic status and underscores the need for improving our understanding of the social and built environment factors associated with neighborhood socioeconomic status.

Citation Format: Theresa H.M. Keegan, Salma Shariff-Marco, Juan Yang, Scarlett Lin Gomez. Impact of the built environment on obesity. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr PL01-04.