New healthy checkout policy cuts soda sales and boosts snack choices

The checkout lane has long been retail’s most reliable trap. Engineered with bright lighting, vivid packaging, and shelf placement exactly at eye level, the final meters of a supermarket trip are deliberately designed to convert waiting time into impulse purchases of candy, chocolate, and soda. In March 2021, the city of Berkeley, California decided to disarm that trap, becoming the first city in the world to ban the display of sugary beverages and snacks in checkout aisles of large retail stores. A new study published in The Lancet Public Health now provides the most comprehensive evidence yet that this first-of-its-kind healthy checkout ordinance (HCO) changed what shoppers actually bought—and, just as importantly, reveals where the policy’s design falls short of its full public health potential.

Researchers at Boston University School of Public Health (BUSPH) and the University of California, Davis (UC Davis) analyzed retail scanner data from 71 stores across Berkeley and three comparison cities—Davis, Oakland, and Sacramento—covering quarterly sales of candy and soda by volume, along with healthier items such as nuts, seeds, and bottled water. The study window stretched from March 2019 through December 2023, a period deliberately chosen to capture sales both before and after the ordinance took effect and before it became enforceable on January 1, 2022. That two-phase timeline proved crucial. Because the policy was implemented in 2021 but only became enforceable in 2022, the researchers could separately estimate the effects of voluntary adoption and of active enforcement, offering a rare natural experiment in how the teeth of a regulation shape its outcomes.

The headline finding is striking: soda sales decreased substantially in Berkeley after the HCO was both implemented and enforced. The decline in sugary drink purchases was consistent across the study period, suggesting that removing soda from checkout displays—combined with the city’s ability to penalize noncompliance—genuinely curbed impulse buying of sugar-sweetened beverages. For a country in which, according to the Centers for Disease Control and Prevention, six in ten young people drink a sugar-sweetened beverage on any given day, even modest shifts at the point of sale carry meaningful implications for population health.

The picture for candy proved more nuanced. Sales of small-packaged candy—the format most typically stocked in checkout aisles—decreased significantly in supermarkets after enforcement began. This detail matters because the researchers deliberately examined sales by package size to test whether the ordinance achieved its intended goal: reducing purchases of the snack-sized items most associated with checkout displays. The drop in small-format candy in supermarkets, which were among the store types with the highest compliance, indicates that the policy did influence purchasing behavior in precisely the way its designers hoped.

Yet total candy sales told a different story. Overall candy purchases increased moderately after the policy was implemented, though that increase did not persist after enforcement. At the same time, sales of healthy, lower-sugar items such as snack-sized nuts and seeds rose as well—a sign that some shoppers, denied the candy at the register, substituted toward more nutritious options. The coexistence of rising total candy sales with rising healthy snack sales suggests that the ordinance reshaped the composition of impulse purchases more than it suppressed snacking altogether.

Store type emerged as a decisive moderator of the policy’s effectiveness. Supermarkets, which complied most thoroughly with the HCO, experienced the greatest declines in sales of sugary items. Drug stores, which complied the least, showed no reduction in candy or soda sales at all. This gradient is perhaps the study’s most actionable insight: the health benefits of checkout restrictions track directly with enforcement and compliance, not merely with the existence of a law on the books. A policy that stores ignore is a policy that fails.

“Through bright lighting, colorful packaging, and eye-level placement, checkout lanes are intentionally designed to draw shoppers’ attention to snacks and beverages with high added sugar,” said study co-lead author Dr. Justin White, associate professor of health law, policy and management at BUSPH, who led the analysis with Dr. Ziyue Xu, research scientist in the same department. “Our findings suggest that healthy checkout policies can help reduce impulsive purchases and even encourage healthier snack choices, but it is critical for cities to actively enforce these policies if they aim to see meaningful and sustained decreases in sugary product sales.”

White also emphasized a structural limitation of the ordinance itself. “The healthy checkout ordinance does not prohibit stores from simply relocating sugary drinks and snacks to other areas of the store, or including them in seasonal displays,” he noted. Because the policy regulates only the checkout zone, retailers retain full freedom to promote candy and soda elsewhere—in end caps, promotional aisles, and seasonal arrangements. This likely explains why total candy sales did not fall even as checkout-specific, small-format purchases declined. The scanner data, by design, could not capture these other placement or promotional changes that stores may have made to compensate for the lost checkout exposure.

The new findings build on earlier work led by Dr. Jennifer Falbe, senior and corresponding author of the study and associate professor of nutrition and human development in the Department of Human Ecology at UC Davis. Her prior assessments of store checkouts in Berkeley and nearby cities established that candy and sugar-sweetened beverages were among the most common items found in checkout aisles, and demonstrated that the amount of added sugar in checkout foods and beverages fell by 70 percent in the first year after the HCO was implemented. The latest study extends that story from what stores stock to what shoppers buy, closing the loop between retail environmental change and consumer behavior. “No single policy alone can address the problems with our food system,” Falbe said. “However, expanding healthy checkout policies to cover other prime locations and pairing this policy with evidence-based strategies like mandatory front-of-package labeling, sweetened-beverage excise taxes, and subsidies for healthy foods, could improve diet quality.”

The stakes of these findings extend well beyond Berkeley. Overconsumption of candy and sugar-sweetened beverages contributes to type 2 diabetes, heart disease, and tooth decay, and the 2025–2030 federal Dietary Guidelines for Americans recommend that children under 11 consume no added sugar at all. As other cities in the United States and other countries consider adopting similar checkout standards, the Berkeley experience offers both a proof of concept and a cautionary tale: the policy works where it is enforced and where its scope matches the retail strategies it seeks to counter.

The study also points toward regulatory synergy on the horizon. The US Food and Drug Administration is already weighing a mandatory front-of-package labeling rule, though the final label design remains undetermined. Falbe argued that a well-designed label could make placement policies far easier to administer. “If the FDA moves forward with a well-designed front-of-package label, they could make it easier to implement healthy-product-placement policies,” she said. “Stores and city inspectors could use ‘high in added sugar’ or ‘high in sodium’ labels, to spot products that should not be placed in prime locations like checkout lanes.” In other words, a standardized label would give both retailers and enforcement officers a clear, objective criterion for determining which products belong in the checkout lane and which do not—removing much of the ambiguity that currently complicates compliance.

Methodologically, the quasi-experimental design—comparing Berkeley stores against matched stores in nearby cities before and after the policy phases—strengthens causal inference in a field where randomized trials of retail policy are rarely feasible. By including multiple product categories and package sizes, and by stratifying results by store type and compliance level, the researchers were able to disentangle effects that a simpler before-and-after analysis would have blurred. The inclusion of nuts, seeds, and bottled water as outcome measures also allowed the team to detect substitution toward healthier choices, an outcome that many food policy evaluations overlook.

The research was coauthored by investigators at the Andrew M. and Jane M. Bursky School of Public Health at Washington University in St. Louis, the University of Illinois Chicago School of Public Health, and Stanford University School of Medicine, and was supported by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health under Award Number R01DK135099.

Taken together, the findings position healthy checkout ordinances as a promising but incomplete tool in the fight against excess sugar consumption. They reduce the most impulsive, most heavily engineered sugary purchases—sodas and snack-sized candies at the register—and nudge some shoppers toward nuts and seeds instead. But as long as stores can pivot their promotional muscle to other corners of the shop, total candy sales may remain stubbornly resistant. The Berkeley experiment suggests that the future of food retail policy lies not in single interventions but in layered ones: checkout restrictions paired with taxes, labeling, and enforcement that give cities both the mandate and the means to change what shoppers see—and ultimately what they buy.