Nutrient profile systems: a review of applications, validation and emerging developments

Nutrient profile systems (NPSs) are algorithm-based frameworks that classify or score the nutritional value of foods to support consumer guidance and to operationalise nutrition policy. This state-of-the-art review summarises widely used NPS (e.g. Nutri-Score, Health Star Rating, traffic light and warning labels, Food Compass, Nordic Keyhole and NutrInform Battery), highlighting core design features, front-of-pack formats and applications including claims and marketing regulation, procurement and fiscal measures, and reformulation. We synthesise validation evidence from cohort studies and recent meta-analyses linking diets characterised by more favourable NPS scores with lower risks of cardiometabolic disease, cancer and all-cause mortality, while noting ongoing challenges in interpretability, cross-system comparability and governance. Recent developments, including algorithm updates and emerging approaches to incorporate processing (ultra-processing) and environmental sustainability metrics, are discussed. Priorities for next-generation NPS include transparent governance, broader criterion validation across diverse populations, empirically calibrated processing dimensions, and practical, clear communication of nutrition-sustainability trade-offs in real-world settings.