Current soda taxes don’t curb teen obesity: Study

Debate has been heated about whether soda taxes could be an effective tool to help fight obesity, which has become a public health crisis in the US, with more than two-thirds of the population now overweight or obese. This raises the likelihood of a host of obesity-related diseases, including hypertension, diabetes and stroke.

This new study from the University of Chicago, called Associations between State-level Soda Taxes and Adolescent Body Mass Index​, compared state-level taxes on soda sold in grocery stores and from vending machines with adolescent body mass index data collected through the nationally representative ‘Monitoring the Future’ surveys carried out between 1997 and 2006.

The authors wrote: “Current state-level tax rates are not found to be significantly associated with adolescent weight outcomes. It is likely that taxes would need to be raised substantially to detect significant associations between taxes and adolescent weight.”​

Weak link to weight​

Currently 34 states levy a tax on soda sold in grocery stores at an average rate of 3.43 percent, and 39 states tax soda sold through vending machines at an average rate of 4.02 percent. However, the primary goal of these taxes has not been to change behavior but to generate revenue.

The authors said their results only showed a “small and weakly statistically significant” ​association between vending machine soda tax rates and weight among teenagers who were at risk of overweight. But they added that small findings were not surprising considering that they would expect the relationship between soda taxes and BMI to be less strong than a link between taxes and soda consumption, for which they did not have data.

While this study focused on the effects of tax on adolescent weight, a previous study investigating the relationship between tax and obesity among adults did find a link, saying that “states that had repealed a soft drink or snack food tax were 13 times more likely to have had a high relative increase in obesity prevalence.”​

In addition, lower fruit and vegetable prices have been associated with lower adolescent weight, the authors said.

Recently considered taxes​

Several governments have considered soda taxes as part of their public health strategy recently, including the US Congressional Budget Office, which has considered a three-cent per 12-ounce tax on sweetened beverages; the governor of Massachusetts who proposed applying the state’s five percent tax to candy and soft drinks; and the governor of New York who proposed an 18 percent tax on sweetened beverages. None of these proposals has gone ahead.

Source: Journal of Adolescent Health​

45 (2009) S57–S63

“Associations between State-level Soda Taxes and Adolescent Body Mass Index”​

Authors: Lisa M. Powell, Jamie Chriqui, and Frank J. Chaloupka.