Association of individual-level and neighborhood-level social capital with changes in BMI

Background: Previous research suggests that the neighborhood social environment is associated with health outcomes including weight status and cardiovascular health. For example, lower levels of community collective efficacy have been associated with overweight and obesity. However, there has been little research examining whether the neighborhood social environment is related to longitudinal changes in health and weight status.

Methods: Data are from Waves 1 and 2 of the Los Angeles Family and Neighborhood Survey (LAFANS), a multi-level, population-based survey of individuals sampled from 65 neighborhoods in Los Angeles County administered from 2000-2002 and 2006-2008, respectively. We examine the longitudinal association of individual- and neighborhood-level social capital with adult BMI. Measures of social capital included social cohesion (an indicator of trust among neighbors), social exchange (an indicator of reciprocity among neighbors), and intergenerational ties (an indicator of connections between adults and children). Measures were constructed at the individual level and also aggregated at the neighborhood level (census tract).

Results: Longitudinal multilevel regression models adjusting for age, gender, race/ethnicity, and household income and accounting for clustering at the census tract indicated that higher neighborhood-level social cohesion, social exchange and intergenerational closure were associated with decreases in BMI. However, none of the individual-level indicators of social capital were associated with changes in BMI over time.

Discussion: Neighborhood-level indicators of social capital longitudinally predicted changes in BMI, whereas individual-level indicators did not. These findings suggest that neighborhood-level social characteristics can be an important long-term determinant of weight status among residents.