Types and spatial patterns of neighborhood greenery matter in associations with weight status in women across 28 U.S. communities
Excess body weight is a risk factor for many chronic diseases. Studies have identified neighborhood greenery as
supportive of healthy weight. However, few have considered plausible effect pathways for ecosystem services (e.
g., heat mitigation, landscape aesthetics, and venues for physical activities) or potential variations by climate.
This study examined associations between weight status and neighborhood greenery that capture ecosystem
services most relevant to weight status across 28 U.S. communities.
Weight status was defined by body mass index (BMI) reported for 6591 women from the U.S. Sister Study
cohort. Measures of greenery within street and circular areas at 500 m and 2000 m buffer distances from homes
were derived for each participant using 1 m land cover data. Street area was defined as a 25 m-wide zone on both
sides of street centerlines multiplied by the buffer distances, and circular area was the area of the circle centered
on a home within each of the buffer distances. Measures of street greenery characterized the pedestrian environment
to capture physically and visually accessible greenery for shade and aesthetics. Circular greenery was
generated for comparison. Greenery types of tree and herbaceous cover were quantified separately, and a
combined measure of tree and herbaceous cover (i.e., aggregate greenery) was also included. Mixed models
accounting for the clustering at the community level were applied to evaluate the associations between neighborhood
greenery and the odds of being overweight or obese (BMI > 25) with adjustment for covariates selected
using gradient boosted regression trees. Analyses were stratified by climate zone (arid, continental, and
temperate).
Tree cover was consistently associated with decreased odds of being overweight or obese. For example, the
adjusted odds ratio [AOR] was 0.92, 95% Confidence Interval [CI]: 0.88–0.96, given a 10% increase in street tree
cover at the 2000 m buffer across the 28 U.S. communities. These associations held across climate zones, with the
lowest AOR in the arid climate (AOR: 0.74, 95% CI: 0.54–1.01). In contrast, associations with herbaceous cover
varied by climate zone. For the arid climate, a 10% increase in street herbaceous cover at the 2000 m buffer was
associated with lower odds of being overweight or obese (AOR: 0.75, 95% CI: 0.55–1.03), whereas the association
was reversed for the temperate climate, the odds increased (AOR: 1.19, 95% CI: 1.05–1.35).
Associations between greenery and overweight/obesity varied by type and spatial context of greenery, and
climate. Our findings add to a growing body of evidence that greenery design in urban planning can support
public health. These findings also justify further defining the mechanism that underlies the observed
associations.