Fast Food and Obesity
| Peter Klein |
A new Australian public-service ad compares fast food to heroin: “You wouldn’t inject your children with junk. So why are you feeding it to them?” (See the ad, along with Katherine Mangu-Ward’s funny meditations on the theme.) But does fast food really contribute to health problems, particularly obesity?
Not much, according to Richard Dunn’s study, “The Effect of Fast-Food Availability on Obesity: An Analysis by Gender, Race, and Residential Location,” in the July 2010 issue of the American Journal of Agricultural Economics (it’s peer reviewed, and not funded by corporations!). Previous research finds links between the number and density of fast-food restaurants and health problems, but has difficulty identifying cause and effect (fast food could make people overweight, but fast food restaurants could be put in areas where people are overweight anyway). Dunn uses the number of interstate exits as an instrument for restaurant location to tease out the causal relations, and finds little overall effect of fast food on obesity — none at all in rural areas, a bit in medium-density areas, and only among women and minorities.