Effects of a healthy checkout ordinance on the sale of soft drinks and confectionery in Berkeley, CA, USA: a quasi-experimental study.

Abstract

Placing products in prominent locations such as store checkouts can promote impulse purchases of foods and beverages high in added sugars. On March 1, 2021, Berkeley, CA, USA, implemented the world's first mandatory healthy checkout ordinance (HCO), prohibiting the display of foods high in added sugars and sweetened beverages, including soft drinks (known as soda in the USA) and confectionery (known as candy in the USA), at store checkouts. The HCO was enforceable on Jan 1, 2022. We aimed to evaluate the association of the HCO with sales of soda (sweetened with sugar or non-sugar sweeteners) and candy in the city. In this quasi-experimental study, we analysed Circana retail scanner data (March 3, 2019, to Dec 31, 2023) from 71 stores in Berkeley and three other comparison cities in California, restricted to chains operating in Berkeley. Data were point-of-sale records for selected food and beverage categories, which were aggregated by store and year-quarter for analysis. Primary outcomes were quarterly volume sales of soda and candy overall and by package size, using thresholds based on products commonly sold at checkouts. Using difference-in-differences regressions with store and year-quarter fixed effects, we estimated the association of the HCO with outcomes after its implementation and after it became enforceable. Circana data included 71 (39%) of 183 identified standalone chain locations across the four cities: 19 (20%) of 93 supermarkets, 42 (59%) of 71 drugstores (ie, retail shops that combine a pharmacy with a general convenience store), and ten (53%) of 19 mass merchandisers. The analytical sample comprised more than 9 million product-store-month soda observations (1·0 million in Berkeley) and more than 52 million product-store-month candy observations (5·6 million in Berkeley), aggregated to 1420 store-quarter observations per outcome. After implementation, the estimated difference in mean soda sales was -2478 L per store-quarter (95% CI -5228 to 272; -23·4%), relative to comparison cities. After enforcement, soda sales were -3891 L per store-quarter (-7774 to -7; -39·5%). Estimates indicated reduced sales of large packages of soda after enforcement (-3800 L, -7571 to -30; -42·5%) and varied by store type. Overall candy sales increased after implementation (220 kg per store-quarter, 95% CI 21 to 420; 10·4%); after enforcement, the estimated difference was 156 kg (95% CI -78 to 390; 7·8%), with the 95% CI including the null. Supermarket sales of small packages of candy decreased by 132 kg after implementation (95% CI -212 to -51; -34·9%) and 156 kg after enforcement (-233 to -78; -43·2%). Berkeley's mandatory HCO was found to be associated with decreased soda sales but not decreased overall candy sales after its enforcement. Estimates varied by product category, package size, and store type. Mandatory checkout standards can influence purchases, but implementation and enforcement strategies might need tailoring. US National Institute of Diabetes and Digestive and Kidney Diseases and Bloomberg Philanthropies.