An Expert Consensus Framework for a Database on Ileal Amino Acid Digestibility and Protein Quality Scoring From Foods Consumed by Humans

Overview & Synopsis

Objectives: Food Protein Quality is best measured by the amino acid scoring that relates their indispensable amino acid content to a reference profile after correction for digestibility. Digestibility is measured at the terminal ileum for calculation of the ileal Protein Digestibility Corrected Amino Acid Score (ileal-PDCAAS) and the Digestible Indispensable Amino Acid Score (DIAAS). In 2022, the Food and Agriculture Organisation (FAO) and the International Atomic Energy Agency (IAEA) decided to create a database on amino acid oro-ileal digestibility for protein quality scoring of human foods. Methods: The 2022 FAO/IAEA Technical Meeting recommended the collection of protein and amino acids oro-ileal digestibility data obtained in vivo in humans, pigs and rats. A systematic review was carried out using bibliographic databases (Scopus, Web of Science, PubMed Central) to end of November 2024. An FAO/IAEA technical advisory group was held in March 2024, and an expert meeting held in November 2024 to guide the database construction and architecture and define the inclusion criteria. Results: A total of 5,313 published articles were identified, of which 1,088 were eligible after title and abstract screening, and a final ~550 full text articles were included for data extraction. The database included food description (name, food group, origin, seasonality, processing etc.), protein and amino acid content (per 100g food and per g of protein), moisture content, protein and amino acid ileal digestibility, and ileal score calculations (ileal-PDCAAS, DIAAS) by age groups. Data on the metabolic availability of amino acids, measured by indicator amino acid oxidation (IAAO), were separately included, considering that they are a different measurement. Conclusions: The literature is sufficiently advanced to support a database on ileal digestibility of amino acids in human foods. Standardised protocols should be used, animal data should be validated against human data, and in the future in vitro data could be included after validation. A final goal of the database is to help in the development of dietary guidelines to best ensure the protein needs of human populations.