Serving size and consumption frequencies in food-based dietary guidelines: A global scoping review

Food-based dietary guidelines (FBDGs) shape health and nutrition policies, promoting balanced and sustainable diets. They recommend appropriate serving sizes and consumption frequencies across food groups. A clearer understanding of how serving sizes are defined globally is also essential for advancing harmonized food-labeling practices, an increasingly relevant objective for public health and industry. This study examines how these aspects are addressed globally, assessing the type and consistency of information provided. FBDGs were retrieved from the FAO database if available in English or Italian and published before March 2024. Of 100 documents, 60 were included in the final analysis. Quantitative data on serving sizes and consumption frequencies were found in 35 FBDGs, while 16 provided partial details, and 9 lacked quantitative advice. High variability emerged, particularly in serving sizes for dairy products and how consumption frequency is expressed (daily vs. weekly). While some countries provided detailed quantitative guidance, others relied on qualitative or partial recommendations. This inconsistency complicates policy development and public understanding. Standardizing serving size definitions can improve food labeling, dietary recommendations, and global health policies by enabling better comparisons of dietary data across populations. Greater harmonization at regional levels is crucial for strengthening food policy actions and promoting healthier diets.