Impact of new octagonal front-of-pack labeling on purchasing probability of processed and ultra-processed foods in Colombia

Front-of-pack labeling (FOPL) has emerged as a key public health tool to inform consumers about the nutritional quality of foods and encourage healthier purchasing decisions. Among the various FOPL systems implemented worldwide, warning labels have gained prominence in Latin America due to their effectiveness in discouraging the consumption of unhealthy products. This study evaluates the impact of black octagonal front-of-pack warning labels (FOPL), introduced by Resolution 254 of 2023 in Colombia, on consumer purchasing intentions for processed and ultra-processed foods. Through an online experimental survey involving 490 food shoppers, 22 commercially available products were evaluated with and without the new labeling. The research examines the relationship between the number of warning labels and purchase probability, as well as the role of individual factors. The findings demonstrate a significant reduction in purchase probability for 20 of the 22 evaluated foods, with an additive effect of the number of labels. Products with four labels showed the largest impact (Cohen's d = 0.34), while those with a single label exhibited minimal changes (Cohen's d = 0.17). Greater label sensitivity was observed among participants with higher education levels and greater familiarity with nutritional labeling. Additionally, a marginally significant inverse relationship was found between product price and the change in purchase probability. These findings offer early evidence on the effectiveness of the Colombian FOPL policy under ecologically valid conditions, and highlight the importance of complementary strategies to enhance its impact across different consumer segments.