Relationship between outdoor food and beverage advertising and obesity

INTRODUCTION: Recent research has shown that neighborhood characteristics are associated with obesity prevalence. While food advertising in periodicals and television has been linked to overweight and obesity, it is unknown whether outdoor advertising is related to obesity. METHODS: To test the association between outdoor food advertising and obesity, we analyzed telephone survey data collected from 220 census tracts in Los Angeles and Louisiana. We linked self-reported information on BMI and soda consumption with a database of directly observed outdoor advertisements. RESULTS: Census tracts with a higher percentage of low-income minority populations were more likely to have food advertising compared to high-income, predominantly white census tracts (OR 2.63, 95% CI: 1.12-6.18, p<0.03). The higher the percentage of outdoor advertisements promoting food or non-alcoholic beverages within the census tract, the greater the odds of obesity among its residents, controlling for age, race and educational status. For every 10% increase in food advertising, there was a 1.05 (95%CI 1.003 -1.093, p<0.04) greater odds of being overweight or obese, controlling for other factors. A similar relationship was also present between advertising and soda consumption (IRR 1.06, 95% CI: 1.03-1.09, p<0.01). Given these predictions, compared to an individual living an area with no food ads, those living in areas with 30% food ads would have a 2.6% increase in the probability of being obese. CONCLUSIONS: There is a relationship between the percentage of outdoor food advertising and overweight/obesity. Public health officials may want to test whether reducing food advertising in a community helps to reduce the obesity rate.