Does change in the neighborhood environment prevent obesity in older women?

Neighborhood environment is consistently associated with obesity; changes to modifiable aspects of the neighborhood environment may curb the growth of obesity in the US and other developed nations. However, currently the majority of studies are cross-sectional and thus not appropriate for evaluating causality. The goal of this study was to evaluate the effect of a neighborhood-changing intervention on changes in obesity among older women. Over the past 30 years the Portland, Oregon metropolitan region has made significant investments in plans, regulatory structures, and public facilities to reduce sprawl and increase compact growth centers, transit-oriented development approaches, and green space. We used geocoded residential addresses to link data on land-use mix, public transit access, street connectivity, and access to green space from four time points between 1986 and 2004, with longitudinal data on body mass index (BMI) from a cohort of 2003 community-dwelling women aged 66 years and older. Height and weight were measured at clinic visits. Women self-reported demographics, health habits, and chronic conditions, and self-rated their health. Neighborhood socioeconomic status was assessed from census data. Neighborhood walkability and access to green space improved over the 18-year study period. On average there was a non-significant mean weight loss in the cohort between baseline (mean age 72.6 years) and the study's end (mean age 85.0 years). We observed no association between neighborhood built environment or change in built environment and BMI. Greater neighborhood socioeconomic status at baseline was independently associated with a healthier BMI at baseline, and protected against an age-related decline in BMI over time. BMI decreases with age reflect increased frailty, especially among older adults with complex morbidities. Future research should consider the influence of the neighborhood environment on additional relevant health outcomes and should include measures of the social environment in conjunction with built environment measures.