Effects of urban sprawl on obesity

In this paper we examine the effect of changes in population density urban sprawl between 1970 and 2000 on BMI and obesity of residents in metropolitan areas in the U S We address the possible endogeneity of population density by using a two-step Instrumental variables approach We exploit the plausibly exogenous variation in population density caused by the expansion of the US Interstate Highway System which largely followed the original 1947 plan for the Interstate Highway System We find a negative association between population density and obesity and estimates are robust across a wide range of specifications Estimates indicate that if the average metropolitan area had not experienced the decline in the proportion of population living in dense areas over the last 30 years the rate of obesity would have been reduced by approximately 13% (C) 2010 Elsevier B V All rights reserved