Soda taxes, obesity, and the perils of complexity

Obesity rates continue to steadily rise in the United States, with nine states having more than 30% of adults reporting body mass indices in the obese range. Despite widespread attention and millions of dollars spent in researching, preventing, and treating obesity, every state experienced a significant increase between 1999 and 2009, with an overall increase of 1.1% between 2007 and 2009. Although there are numerous ideas on what might work, we do not have a single real world–tested example of a state reversing the obesity trend. Tobacco control is often held up as an example of a public health success story in changing health behaviors. A comprehensive approach with a focus on policy change helped to greatly reduce tobacco use rates in numerous states. However, the tobacco policy landscape (i.e., smoking bans, taxes, and sales to minors) is much smaller than the potential policy changes for physical activity and nutrition. As Chaufan et al. point out in their thoughtful accompanying article, there is no clear data that taxes on sugar-sweetened beverages will have an impact on obesity rates. Although this is probably true, it is unclear what polices, if any, will have an effect on obesity rates. For physical activity, more than 150 jurisdictions have passed complete street policies. These policies mandate that any new street accommodate all types of users including pedestrians, bicyclists, and mass transit. Although this is a desirable goal for numerous reasons, the effect on obesity may not be seen for some time or at all. Chaufan et al. argue that increases in taxes on sugarsweetened beverages would not greatly reduce consumption or move it to other unhealthy beverages based on price elasticity. However, as seen in tobacco and hard alcohol, children and young adults are often the most sensitive to changes in price. Because obesity often starts in childhood, prevention at this age may be influenced by reductions in sugar-sweetened beverage consumption; however, the effects on adults might be nonexistent. Given the experience with other consumable substances, this is at least a plausible model that can really only be tested once communities start adopting these taxes. Chaufan et al. finish their article by supporting the idea of taxes on sugar-sweetened beverages as a means of revenue generation for public health programs, including those dedicated to obesity and dental hygiene. Although this is a noble and rationale argument, it is not often how legislative bodies operate. Elected officials are much more likely to support these types of taxes if the funds go into the general fund to help balance the budget or pay for other needed services. Earmarking of tax funds often leads to supplanting of current general funded programs or changes to the statute when the budget gets tight. For example in fiscal year 2010, the 46 states that settled with the tobacco companies received more than $25 billion in payments but spent only 2.3% of that on tobacco prevention and control, Given this track record, it is hard to believe that any significant portion of revenues generated by taxes on sugar-sweetened beverages will be used for public health programs at least until public health advocates become more effective in protecting public health resources.