A recent study published in the journal BMC Public Health, “Outdoor advertising, obesity, and soda consumption: a cross sectional study,” investigating the relationship between obesity and outdoor advertising, found that areas with more outdoor advertising had higher rates of obesity than those with fewer ads. Researchers concluded that if this association was further proven with additional research, it could be used to inform policy related to “obesity generating” advertising.
However, in an op-ed published in The New York Times, a pair of science journalists point out the inherent flaws in these conclusions. They note that the journal study generated data which cannot be used to assert a cause-and-effect; in fact, one might also conclude that food vendors are more likely to advertise in areas with higher obesity rates because those individuals are more likely to buy their products. They also highlight that “the fact that the causal conclusion may coincide with a moral belief – that it is wrong to tempt people who overeat by showing them ads for food – does not make it valid.”
Instead, the NYT op-ed suggests that in the absence of a randomized controlled trial in which people or places are randomly assigned to receive different treatments – amount of outdoor food advertising – another alternative would be to restrict outdoor food ads temporarily in certain areas and then compare prevalence of obesity over time. They caution that using the results of the original study could lead to “erroneous and even harmful policies, and ultimately the deprecation of science as a guide to wise government.”
On a related note, ACSH’s Dr. Ruth Kava did an interview with a local New York radio station, WNYC, discussing Mayor Bloomberg’s recently-invalidated sugary beverage ban. Her takeaway message: Although the ban may have served as an educational tool for consumers, the fact that there was no research that this kind of ban could at all be effective in reducing obesity rates negates that point and supports the Judge’s decision to overrule the ban.