Abstract
INTRODUCTION: In January 2025, the Food and Drug Administration proposed mandating Nutrition Info front-of-package labels, which would indicate whether packaged foods are low, medium, or high in saturated fat, sodium, and added sugars. This study examined whether a label similar to the Food and Drug Administration's proposal improves consumer understanding compared with positive endorsement and other proposed or adopted front-of-package labels and whether effects vary by income, education, race/ethnicity, and nutrition literacy. STUDY DESIGN: This was an online RCT conducted in October-November 2024. SETTING/PARTICIPANTS: National sample of 5,636 U.S. adults who were primary grocery shoppers. INTERVENTION: Participants were randomized to 1 of 6 front-of-package labeling systems: (1) positive (reference group), (2) Nutrition Info (the Food and Drug Administration proposal), (3) high-in nutrient (warnings for high levels of nutrients of concern), (4) positive + Nutrition Info, (5) positive + high-in, and (6) spectrum (rates products from least to most healthy). MAIN OUTCOME MEASURES: Participants viewed 6 pairs of products with their assigned labels and indicated which product they thought was healthier in each pair. Consumer understanding was measured by correct identification of the healthier product across product pairs. Analyses were conducted in 2025. RESULTS: Across product pairs, participants correctly identified the healthier option 56%-90% of the time. Compared with positive labels, Nutrition Info labels led to the greatest improvements in consumer understanding (difference: 18.4 percentage points), followed by positive + Nutrition Info (17.9 percentage points), positive + high-in (11.8 percentage points), spectrum (10.8 percentage points), and high-in (5.3 percentage points) (ps<0.001). Effects did not differ by income, education, or race/ethnicity but differed by nutrition literacy (p-interaction<0.01). Labels improved understanding more for higher-literacy than for lower-literacy participants, with the largest differences for Nutrition Info and positive + Nutrition Info labels. CONCLUSIONS: Findings support the Food and Drug Administration's initiative to implement mandatory front-of-package labels. Nutrition Info labels improved consumer understanding the most but may not serve all nutrition literacy groups equally. TRIAL REGISTRATION: NCT06516627.