Public policy makers from around the world (e.g., United Kingdom, Ecuador, and Chile) have launched different initiatives to emphasize the importance of displaying easy-to-interpret nutritional information on food packages. This effort has resulted in new regulations requiring food manufacturers to display traffic light nutritional labels. Previous studies provide mixed results about the effectiveness of traffic light labels on influencing consumers to choose healthy products. This research explores the role of consumers' brand familiarity and attention level as factors that explain the limited efficacy of traffic light nutritional labels. Moreover, we test whether brand trust is the underlying mechanism that decreases consumers' alertness to traffic light nutritional labels. Our results suggest that brand familiarity and brand trust together create a shield that protects the product from being evaluated as unhealthy, even in the presence of warnings from traffic light nutritional labels. Data from four experiments support our findings using different label formats, food product types, and participants from countries that have implemented traffic light nutritional labels.