How Much Do Front-Of-Pack Labels Correlate with Food Environmental Impacts?

**Background:** Non-communicable diseases cause 42 million deaths annually worldwide, and food systems account for 34% of global anthropogenic GHG emissions. Front-of-pack labels (FOPLs) have been developed to promote healthier food choices, but their alignment with environmental sustainability has not been thoroughly investigated. This study examines correlations between various FOPLs and food environmental impact indicators.

**Methods:** The study used a stepwise design. First, a literature search identified 182 food commodities from three life cycle assessment (LCA) papers. Eight environmental indicators were collected: global warming potential (GWP), greenhouse gas emissions (GHG), carbon footprint, water withdrawal, water footprint, land use, acidification, and eutrophication. Four FOPLs were selected: Nutri-Score (NS), Health Star Ratings (HSR), NutrInform Battery (NIB), and Israeli food labels (IFLs), plus the Health Canada Surveillance Tool (HCST). Three healthy and sustainable diets were included as positive controls: Mediterranean diet (MD), Italian Dietary Guidelines (ITA-GL), and EAT-Lancet diet. Food ranks were calculated for each scale. A composite index (Food Sustainability Mazziotta-Pareto Index, FS-MPI) was developed to summarize environmental indicators. Spearman correlations and hierarchical cluster analysis were performed.

**Key Results:** The eight food scales showed correlations ranging from 0.030 to 0.824 (absolute values). Healthy diets showed the strongest correlations with environmental indicators (MD: R=0.738 with FS-MPI; EAT-Lancet: 0.705; ITA-GL: 0.676). Among FOPLs, portion-based scales performed better: NIB (R=0.497 with FS-MPI) and HCST (R=0.431), compared to 100 g-based scales: IFLs (R=0.379), NS (R=0.353), and HSR (R=0.185). Cluster analysis revealed four subgroups: healthy diets, portion-based FOPLs (NIB, HCST), 100 g-based FOPLs (NS, IFLs), and HSR alone. Within-category analysis found no solid evidence explaining these differences.

**Clinical Implications:** Current FOPLs, particularly those based on 100 g standards, show weak-to-moderate correlations with environmental sustainability indicators. Portion-based FOPLs demonstrate better alignment with environmental metrics, suggesting that incorporating serving size and frequency into algorithms may better integrate health and sustainability messaging. The findings support calls to redesign FOPLs using a multidisciplinary approach that includes environmental sustainability as a key component, rather than focusing solely on healthiness.