Soda tax may not be the solution to obesity epidemic

Is increasing taxes on sugar-sweetened beverages really the key to curbing the obesity epidemic? According to a recent study, not really.

“Some older studies suggesting taxes on sugar-sweetened beverages will reduce obesity by 20% rely on household data instead of individual consumption patterns, and they assume that individuals don’t replace the calories in the soda with calories from another source,” said Jason Fletcher, health economist at the University of Wisconsin-Madison.

“In contrast, our study found that increases in soft drink tax rates do correlate to less soda consumption, but not a reduction in calorie intake.”

Researchers from the university conducted two studies which reviewed data from the National Health and Nutrition Examination Surveys (NHANES) and data from the states of Ohio and Arkansas in the early 1990s, during which time both states substantially increased soda taxes.

The NHANES data show that increased taxes on soft drinks are unlikely to have an impact on overall caloric intake, Fletcher said. Although the increased taxes had an impact on body mass index of people in the study, Fletcher says this amount “is small in magnitude and not statistically significant”.

Weight outcomes in Ohio and Arkansas were compared with control groups from other US states. Unfortunately, the results here were not clear-cut: the apparent effects of a soda tax depended on which control group the study participants were compared to. In addition, although the tax seemed to reduce body mass index and obesity in Arkansas when compared with control states, the tax actually increased body mass index in Ohio.

“Our results cast serious doubt on the assumptions that proponents of large soda taxes make about the effects on population weight,” said Fletcher.

“Given that people substitute other calories when they give up soda, these new results suggest we need fundamental changes to policies that make large soda taxes a key element in the fight to reduce overall obesity rates.”

The study is published in the journal Health Economics