Researchers at the University of Illinois at Chicago have revealed that obesity is more prevalent in areas with lower educational attainment and certain ethnic profiles than in areas of suburban sprawl.
Researchers at UIC's Urban Transportation Center revisited their 2005 analysis of data from about 7 million northern Illinois drivers licenses, which found that body-mass index scores in most city neighborhoods differ little from those in the farthest outlying areas.
The 2005 findings contradicted the conventional wisdom that city dwellers are thinner because their dense, centralized environment encourages walking, while suburbanites and rural residents tend to drive to widely scattered destinations.
The new analysis expanded the data set by comparing personal and environmental attributes at the zip-code level throughout the 2005 study area: Cook, DuPage, Kane, Lake, McHenry and Will counties in the Chicago metropolitan area, and the more rural DeKalb, Kendall, Grundy and Kankakee counties.
The data confirmed that sprawl is not significantly associated with obesity, the researchers said, although drivers living in most neighborhoods closer to downtown Chicago have slightly lower body-mass indexes than those living very far from the city.
Within zip codes, body-mass indexes increased with age and male gender, and also with the percentage of zip-code residents who commute by car, are African American or Latino, or own their homes.
The prevalence of obesity decreases in zip codes with higher median income and more residents who have attended college.
Paul Metaxatos, UIC research assistant professor, said the results of the study can inform urban planning initiatives.
"Ambitious land use policies to address obesity may have little success with the low-income ethnic minorities who are most in need of assistance," Metaxatos said.
"Those in marginal, transportation-disadvantaged communities would benefit from better access to medical help, better food markets, and information about lifestyle modifications."