Associations of Cumulative and Point-in-Time Neighborhood Poverty and Walkability with Body Mass from Age 30 to 39

Few studies examining the effects of neighborhood exposures have accounted for longitudinal residential history. This study examined associations of body mass index (BMI, kg/m²) with neighborhood-level walkability and poverty, both assessed concurrently and cumulatively in the years leading up to BMI assessment. Participants (N = 808) were from a cohort study of individuals originally recruited from public schools in Seattle, Washington, in fifth grade in 1985. Height and weight for BMI were obtained at four assessments at ages: 30 (in 2005), 33, 35, and 39. Participants also completed residential timelines listing each address where they lived from ages 28 to 39, creating a continuous record of addresses and moves. Neighborhood-level walkability and poverty were based on census block groups of each address. Generalized estimating equation models estimated associations of standardized neighborhood variables, both at point-in-time concurrently with assessment of BMI and cumulatively up to the time of BMI assessment. Mean BMI across observations was 28.8 (SD = 7.1). After adjusting for covariates, cumulative walkability was associated with lower BMI (b =  − 0.28; 95% CI: − 0.55, − 0.02), and cumulative neighborhood poverty was associated with higher BMI (b = 0.35; 95% CI: 0.09, 0.60). When examining point-in-time concurrent walkability and poverty with BMI, adjusted associations were close to the null and non-significant. This study provides evidence for a significant role of cumulative exposure to neighborhood built and socioeconomic environments predicting BMI. It underscores the relative strength and importance of cumulative assessments to capture neighborhood exposure not captured through point-in-time assessments.