A new study led by Brian Elbel and Pasquale Rummo from NYU Grossman School of Medicine has found that taxes on sugary drinks may not reduce the number of beverage calories people purchase at fast-food restaurants in the United States. The findings were published on April 2 in the open-access journal PLOS Medicine.

Taxes on sugary drinks have been introduced in several U.S. cities as a public health measure aimed at reducing sugar intake and encouraging healthier choices. Previous research has shown that these taxes can lead to about a 15% drop in sugary drink sales in grocery stores. However, less is known about whether the same effect occurs in restaurant settings, where purchasing habits may differ.

To explore this, researchers analysed six years of sales data, from 2015 to 2020, covering more than 7,300 Taco Bell locations across the country. The study focused on drive-through orders, which make up a large share of fast-food transactions. The researchers compared beverage calories per transaction in 60 restaurants located in areas with sugary drink taxes to similar restaurants in areas without such taxes.

The cities included in the analysis were Albany, Cook County, Oakland, Philadelphia, and Seattle. Each of these locations has implemented a tax on sugary beverages. Their results were compared with matched restaurants in places without such policies to assess any differences in consumer behaviour.

Overall, the study found no meaningful link between sugary drink taxes and the number of beverage calories purchased per order in fast-food settings. This suggests that taxes of the current size, or taxes alone, may not be enough to change how people choose drinks when ordering fast food significantly.

The researchers suggest that the nature of fast-food purchasing may explain these findings. Customers often choose bundled meals or prioritise convenience and habit over price differences. As a result, they may be less sensitive to small price increases caused by taxes. The authors also note that the taxes in place may be too modest to influence behaviour in these settings, or that consumers respond differently in restaurants compared to grocery stores.

More information: Pasquale Rummo et al, Impact of sugary drink taxes on beverage calories purchased in a national fast food restaurant chain: A quasi-experimental study, PLOS Medicine. DOI: 10.1371/journal.pmed.1004642

Journal information: PLOS Medicine Provided by PLOS