Experimental Studies of Front-of-Package Nutrient Warning Labels on Sugar-Sweetened Beverages and Ultra-Processed Foods: A Scoping Review

Policies that require front-of-package nutrient warnings are becoming increasingly common across the globe as a strategy to discourage excess consumption of sugary drinks and ultra-processed foods. However, a better understanding of the pathway through which front-of-package nutrient warnings work, as well as a review of how outcomes being measured in recent studies map onto this pathway, are needed in order to inform policy on the most effective front-of-package label design for reducing purchases of ultra-processed foods. This scoping review described a conceptual model for how front-of-package nutrient warnings affect consumer behavior, examined which of these outcomes are currently being measured, and summarized evidence from randomized controlled experiments. Twenty-two studies that experimentally tested nutrient warnings against a control label or other labeling systems were included for full-text review.