Brazilian front-of-package labeling: a choice-based conjoint and eye-tracking study on the role of the magnifying glass symbol versus all-text warnings

Abstract

Front-of-package labeling (FoPL) systems often use text and visuals to help communicate information about nutrients potentially linked to chronic diseases. While systems like the European Nutri-Score and the Latin black octagon emphasize clear warnings, the magnifying glass, adopted in Brazil and Canada, lacks clarity in its semiotic interpretation, warranting further study. This research conducted two experiments to assess the magnifying glass's impact on consumer choices: one with eye-tracking (n = 30) and another without (n = 408). Fot this, mock packages of dulce de leche were developed for the study. These packages featured statements such as “High in added sugar,” “High in saturated fat,” and “High in added sugar and saturated fat,” presented with or without the magnifying glass symbol. Results showed that combining “High in (…)” warnings with the magnifying glass had a weaker effect on reducing product choice than text-only labels. Additionally, dual-nutrient warnings (sugar and saturated fat) consistently had a stronger negative effect on choices than single-nutrient warnings, regardless of the symbol.