Translating nutrition science into national policy: comparative assessment of the 2025–2030 U. S. Dietary Guidelines and the Italian Mediterranean-based guidelines

provides an opportunity to reassess how evolving nutrition science is translated into policy in a context characterized by high burdens of obesity and cardiometabolic disease. This review presents a comparative qualitative policy analysis of the 2025-2030 DGA and the Italian Dietary Guidelines for Healthy Eating (2018), aiming to identify structural differences and explore potential policy implications. The analysis examines governance mandates, macronutrient targets, protein sourcing, treatment of ultra-processed foods, alcohol guidance, sustainability integration, and cultural framing. Although both countries draw upon a largely shared body of scientific evidence and converge on core dietary principles, notable divergences emerge in policy emphasis and communication strategies. The DGA 2025-2030 adopt a more prescriptive approach focused on chronic disease prevention, with greater emphasis on protein intake, and explicit reference to ultra-processed foods, while sustainability remains outside the policy scope. In contrast, Italian guidelines are framed within a Mediterranean dietary pattern, emphasize plant-based protein sources and integrate environmental sustainability, food waste reduction, and cultural dimension. These differences may reflect national epidemiological and institutional contexts and variations in policy priorities. This policy review identifies policy trade-offs in guideline development and proposes actionable recommendations to enhance coherence between public health priorities, environmental sustainability, and implementation feasibility in future revisions.