Testing Ultra-processed Warning Labels and Not-Ultra-processed Labels in United States

This randomized controlled online experiment will test whether adding an ultra-processed food (UPF) warning label or a positive not-ultra-processed (Not-UPF) label, to the FDA's proposed Nutrition Information Box (NIB) changes consumer perceptions of UPFs among U.S. adults. Participants will be randomized to one of four label conditions and will evaluate UPF and Not-UPF products with different nutritional profiles of 3 food categories: yogurts, cereals, and sliced breads. The primary outcome is shelf choice and the secondary outcomes are correct identification of UPF products, perceived healthfulness, perceived usefulness, and perceived message effectiveness. This experiment aims to answer the following questions: Do UPF warning labels and Not-UPF labels shift shelf choice toward Not-UPF products compared to the NIB alone? Is a UPF warning label more effective than a Not-UPF label at shifting shelf choice, decreasing perceived healthfulness, improving correct identification of UPFs, and increasing perceived usefulness and perceived message effectiveness? Researchers will compare outcomes across the four randomized arms to estimate the independent effect of adding a UPF warning label versus a Not-UPF label beyond nutrient disclosure in the NIB alone.