Taxing soda as a way to reduce obesity rates has been a topic of strong debate recently, with several states, including New York and Mississippi, putting forward the idea. A federal tax on soda fell off the agenda in February, however, after a key congressional committee chose not to consider such a levy.
This latest study, conducted by the non-profit health policy research organization RAND Corporation, examined taxes on soda that existed in certain states in 2004 and compared childhood obesity rates among 7,300 fifth-graders at the time, and how often the children said they drank soda over a two-year period. Existing taxes that differentiated soda from other foods and beverages were small, averaging 3.5 percent, with none larger than seven percent, the researchers wrote.
They found that the taxes made no significant difference to children’s weight overall, but that there was a difference for some at-risk groups, such as those from low-income families, African-Americans, and those who watched a lot of television. Extrapolating from these results, the researchers said a tax of 18 percent could reduce excess BMI (body mass index) gain by 20 percent.
The study's lead author and a senior economist at RAND Roland Sturm said: “If the goal is to noticeably reduce soda consumption among children, then it would have to be a very substantial tax. A small sales tax on soda does not appear to lead to a noticeable drop in consumption, led alone reduction in obesity."
The study was funded by the federal government and the Robert Wood Johnson Foundation.
However, the American Beverage Association said that taxing soft drinks will not reverse the obesity trend.
The association’s president and CEO Susan Neely said: "We understand that governments are facing tough budget challenges. But singling out one item for taxation completely misses the mark in having an effect on the national challenge of obesity."
She added that the effect of a soda tax on obesity would be trivial and that the industry is “stepping up to do its part”.
Sturm said: "Soda taxes do have the potential to help reduce children's consumption of empty calories and have an impact on obesity, but both their size and how they are structured are key to whether they create measurable impact.”
The full study is available online here.