A large-scale quasi-experimental evaluation of added sugar warning labels in restaurants
Summary
In August 2023, New York City (NYC), NY became the first jurisdiction in the US to adopt an added sugar warning label policy, which requires restaurants to display a warning label on menus next to items high in added sugar. The adoption of this policy has the potential to reduce disparities in total sugar consumption and the burden of nutrition-related chronic diseases, including type 2 diabetes, obesity, and heart disease. However, almost no real-world studies have examined whether added sugar warning labels affect purchases of restaurant foods. Moreover, no real-world studies have examined for whom these warning effects are largest. Also unknown are the psychological mechanisms that could explain how added sugar warning labels change behavior. To address these critical gaps and evaluate NYC's first-of-its-kind added sugar warning label policy, we will partner with MFour, an innovative mobile phone application with whom we have completed a rigorous pilot test. Using MFour's ability to send location-based surveys to a panel of participants, we will prospectively collect four repeated cross-sections of receipt data from customers exiting chain restaurants (2 before and 2 after implementation, n=10,000 customers) in NYC and comparison cities from 2023-2026. In addition to receipts, we will collect survey data from the participants, including their demographic characteristics and attitudes, risk perceptions, thoughts, and feelings related to added sugar warnings. This will allow us to examine whether the effect of added sugar warning labels on total sugar purchased from chain restaurants differs by customers' education, income, race, or ethnicity. It also allows us to examine the effects of the warning labels on psychological responses that could explain how labels influence chain restaurant purchases. In a separate analysis, we will use a dataset of all purchases made at Taco Bell restaurants nationwide (including >3 million transactions per year in NYC alone) from 2023-2028 and examine total sugar purchased per transaction in NYC and comparison cities before and after added sugar warning labels are implemented. Our central hypothesis is that added sugar warning labels will reduce total sugar purchased from restaurants in NYC relative to comparison cities, with larger effects among customers with lower education, lower income, and Black or Hispanic identities. Completion of these Aims could lay the groundwork for the adoption of added sugar warning labels across the US to reduce obesity, diabetes, and other nutrition-related diseases (NOSI DK-20-035).