Taxes on sugary drinks have been linked to lower purchases in grocery stores, but a new study suggests that effect may not carry over to fast-food restaurants. Researchers analyzing millions of transactions found no meaningful change in beverage calories ordered at fast-food locations in cities with soda taxes compared with similar areas without them.
The study, published in PLOS Medicine, examined six years of sales data from more than 7,300 Taco Bell locations across the U.S. and found no significant association between sugary drink taxes and beverage calories per transaction. The analysis compared restaurants in five jurisdictions with taxes — Albany, California; Cook County, Illinois; Oakland, California; Philadelphia, Pennsylvania; and Seattle, Washington — with matched locations in areas without such policies.
“Using millions of transactions from six years of sales data, we found that sugary beverage taxes did not influence beverage calories when implemented in five cities in the U.S.,” said study author Pasquale Rummo.
The findings differ from previous research showing that sugary drink taxes are associated with roughly a 15% drop in purchases in grocery store settings. The new study suggests that consumer behavior in fast-food environments may be less responsive to price changes alone.
Researchers point to several possible reasons. In fast-food settings, purchases are often bundled into combo meals, and decisions may be driven more by convenience, habit or value than by the price of individual items like drinks.
“These results suggest that sugary drink taxes may not be effective in reducing beverage calorie consumption in fast food restaurants, as compared to supermarkets,” Rummo said. “This could be because the sizes of sugary drink taxes in the U.S. are too small for consumers or that they just aren’t responsive to price changes in these settings, among other reasons.”
The study was observational and focused on one restaurant chain, which may limit how broadly the findings apply. It also measured beverage calories per transaction rather than total daily intake, meaning it does not capture how people may adjust their consumption elsewhere.
Still, the results highlight an important nuance in how food environments shape behavior. Policies that influence purchasing in one setting may not translate to others, particularly when eating decisions are tied to routine or bundled choices.
Rather than pointing to a single solution, the findings suggest that reducing added sugar intake may require a combination of approaches, including changes in pricing, product offerings and the environments where food decisions are made.
This study was funded by the National Heart, Lung, and Blood Institute. Taco Bell provided data access but did not fund or influence the study.