Outdoor advertising, obesity, and soda consumption: a cross-sectional study.

Background: 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 on adults, aged 18-98, 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: The higher the percentage of outdoor advertisements promoting food or non-alcoholic beverages within a 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<0.03) greater odds of being overweight or obese, controlling for other factors. Given these predictions, compared to an individual living in an area with no food ads, those living in areas in which 30% of ads were for food 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.