Any Way You Slice It: Interaction Effects of Residence in a Smart Growth Community, Time in Residence, Physical Activity and Obesity Risk in Adults

Communities that follow smart growth planning principles are designed to promote walkability and other forms of physical activity. It appears logical to assume that residing in such a community may increase physical activity and decrease obesity risk compared to residents of other, more conventionally designed communities. As part of a large multi-city trial examining the effects of the built environment on parents and children, the present study evaluated the interaction effects of experimental group (residence in a smart growth community as intervention vs. randomized control) on the relationship between waist circumference (cm.) and physical activity (MVPA minutes measured with an Actigraph GT2M accelerometer) in 175 adults, ages 24-62; 43% Hispanic; 78% female. With or without adjusting for age, gender, and ethnicity, regression analysis showed a trend toward lower waist circumference among smart growth community residents the longer they resided in the smart growth community, whereas waist circumference did not differ by length of time in residence for controls. There was a significant interaction effect such that smart growth residents had lower waist circumferences at higher levels of MVPA compared to non-smart growth residents (B=-.024, 1-tailed p=0.04). Findings support the impact of a smart growth community environment on decreasing obesity risk by promoting physical activity. Longitudinal analyses will examine whether these relationships continue over time.