DIAAS is a new method for determining protein quality of human nutrition. DIAAS stands for Digestible Indispensable Amino Acid Score. The DIAAS method has been issued by the Food and Agriculture Organization (FAO) of the United Nations in 2013 and replaces the old method from 1991, called PDCAAS (Protein Digestible Amino Acid Score).
The DIAAS method better reflects the true nutritional value of dietary protein for humans than does the PDCAAS method. The DIAAS method also allows a more accurate assessment of protein quality of a mixture or blend of different dietary protein sources than does the PDCAAS method. Both result from the fact that the DIAAS method generates 9 values per protein or protein blend whereas the PDCAAS only gives 1 value per protein source. Out of the 9 values, the lowest one reflects the DIAAS of the dietary protein (blend).
FAO experts have recommended to implement the DIAAS method for protein quality scoring of foods. The following protein quality claims are recommended:
– DIAAS <75% = No protein quality claim. A protein or protein blend with a DIAAS of less than 75% is considered suboptimal, hence no protein quality claim is allowed. - DIAAS ≥75% - <100% = Good protein quality. A protein or protein blend with a DIAAS of 75%-99% is considered good, but still does not provide an optimal (100%) supply of essential amino acids. - DIAAS ≥100% = Excellent or High protein quality. A protein or protein blend with a DIAAS of 100% or more is considered to be an optimal provider of dietary essential amino acids, hence the claim excellent or high protein quality is allowed.