Impact of nutrient warning labels on choice of ultra-processed food and drinks high in sugar, sodium, and saturated fat in Colombia: A randomized controlled trial

BackgroundFront-of-package nutrient warning labels are one promising policy to inform healthier food choices and purchasing decisions. This study aimed to identify the impact of nutrient warning labels on product selection and the ability to correctly identify products with an excess of critical nutrients, among other outcomes in Colombia.MethodsWe conducted an online randomized experiment among 8,061 Colombian adults in October 2020. Participants were randomly assigned to a front-of-package label condition: nutrient warning, guideline daily amounts (GDA), Nutri-Score, or a no-label condition. First, they viewed a fruit drink with added sugar that was labeled per their assigned condition and one without added sugar, which was only labeled in the GDA and Nutri-Score conditions, and completed selection tasks. The primary outcomes were 1) selection of the fruit drink with added sugar as the fruit drink they would rather buy and 2) correctly identifying which fruit drink was higher in sugar. Next, they viewed four food products (cookies, yogurt, sliced bread, and breakfast cereal) with their assigned condition and answered a series of questions. Finally, they selected which of the three label types would most discourage them from consuming a specified ultra-processed food.ResultsFewer participants in the nutrient warning condition (20%) selected the added sugar fruit drink as the product they would rather buy compared to 24% in the GDA condition (p<.01), 29% in the no-label condition, and 33% in the Nutri-Score condition (both, p<.001). More participants in the nutrient warning condition (88%) correctly identified the fruit drink higher in sugar compared to the no-label condition (68%) and the Nutri-Score condition (65%) (both, p<.001). More participants in the GDA condition (91%) correctly identified the fruit drink higher in sugar compared to the nutrient warning condition (p<.01). Most participants (72%) selected the nutrient warning label as most discouraging, while only 20% selected the GDA label and 9% selected the Nutri-Score label.ConclusionsNutrient warning labels are a promising policy strategy to prevent obesity and diet-related non-communicable diseases in Colombia. Future research is needed to understand the impact of nutrient warning labels on actual ultra-processed food purchases in Colombia. Trial Registration: NCT04567004