The Effect of Fast Food Restaurants on Obesity

We investigate the health consequences of changes in the supply of fast food using the exact geographical location of fast food restaurants. Specifically, we ask how the supply of fast food affects the obesity rates of 3 million school children and the weight gain of over 1 million pregnant women. We find that among 9 grade children, a fast food restaurant within a tenth of a mile of a school is associated with at least a 5.2 percent increase in obesity rates. There is no discernable effect at .25 miles and at .5 miles. Among pregnant women, models with mother fixed effects indicate that a fast food restaurant within a half mile of her residence results in a 2.5 percent increase in the probability of gaining over 20 kilos. The effect is larger, but less precisely estimated at .1 miles. In contrast, the presence of non-fast food restaurants is uncorrelated with obesity and weight gain. Moreover, proximity to future fast food restaurants is uncorrelated with current obesity and weight gain, conditional on current proximity to fast food. The implied effects of fast-food on caloric intake are at least one order of magnitude smaller for mothers, which suggests that they are less constrained by travel costs than school children. Our results imply that policies restricting access to fast food near schools could have significant effects on obesity among school children, but similar policies restricting the availability of fast food in residential areas are unlikely to have large effects on adults. The authors thank John Cawley and participants in seminars at the NBER Summer Institute, the 2009 AEA Meetings, the ASSA 2009 Meetings, the Federal Reserve Banks of New York and Chicago, The New School, the Tinbergen Institute, the Rady School at UCSD, and Williams College for helpful comments. We thank Cecilia Machado, Emilia Simeonova, Johannes Schmeider, and Joshua Goodman for excellent research assistance. We thank Glenn Copeland of the Michigan Dept. of Community Health, Katherine Hempstead and Matthew Weinberg of the New Jersey Department of Health and Senior Services, Craig Edelman of the Pennsylvania Dept. of Health, Rachelle Moore of the Texas Dept. of State Health Services, and Gary Sammet and Joseph Shiveley of the Florida Department of Health for their help in accessing the data. The authors are solely responsible for the use that has been made of the data and for the contents of this article.