Sprawl-Obesity Link Questioned

Over the last several years there have been numerous studies that suggest a linkage between the types of neighborhoods where people live and rates of obesity.  A whole subfield of “Active Living Research” has emerged to understand the reasons why obesity has skyrocketed in recent years.  The idea that living in suburban areas might increase the likelihood to be obese is logical.  Generally North American suburbs are built and organized around facilitating automotive mobility at the expense of pedestrian mobility.  Since suburbanites are forced to drive everywhere they may not be getting as much exercise as people dwelling in a more density-rich environment.

Smart Growth America published a report in 2003 that suggested people living in counties with a higher sprawl index had higher problems with obesity.  They linked census data on sprawl with national health data from the CDC’s Behavioral Risk Factor Surveillance System to substantiate their claims.

Their findings were not without controversy. The Ottawa Citizen is reporting on a new study questioning these claims.  A team led by University of Toronto economist Matthew Turner have written a paper [pdf] suggesting the absence of a link between sprawl and obesity.  Unlike the Smart Growth America study, Turner’s research stems from a longitudinal health data set following the same people from 1988-1994.  With this data, Turner and his colleagues had the luxury of seeing changes in body mass index in specific people as they moved to different environments.  Their analysis indicates that there is no relationship between changes in BMI and sprawl.

The study is still a “working paper,” meaning that it has not gone through the standard process of peer review.  But, nevertheless, the preliminary results are undoubtedly provocative and will probably be scruitinized by the many scholars who have been arguing the opposite for the last several years.