SANTA MONICA, Calif.—Existing taxes on soda, which are typically not much higher than 4 percent in grocery stores, do not substantially affect overall levels of soda consumption or obesity rates, according to a study published in Health Affairs (doi: 10.1377/hlthaff.2009.0061).
Researchers did find, however, that subgroups of at-risk children—children who are already overweight, come from low-income families, or are African American—may be more sensitive than others to soda taxes, especially when soda is available at school. They noted the greater impact of these small taxes could come from the dedication of the revenues they generate to other obesity prevention efforts rather than through their direct effect on consumption.
In this study, the researchers used data on state sales taxes for soda and individual-level data on children to examine whether small taxes are likely to change consumption and weight gain or whether larger tax increases would be needed. According to the Associated Press, they used information from a 2004 national survey of about 7,300 fifth-graders and observed children's height and weight changes during the previous two years, as well as how often the kids said they drank soda and sports drinks. They compared that data with taxes on carbonated drinks that were in effect in 2004. The AP said two-thirds of the children lived in states that had a tax on soda greater than on other food items. The highest was 7 cents tax on each dollar's worth of soda. The average was about 4 cents.