DIAAS stands for “Digestible Indispensable Amino Acid Score” and is a method for assessing protein quality proposed by the Food and Agriculture Organization of the United Nations. It measures how well the essential amino acids of a food can actually be absorbed in the small intestine, instead of only looking at the digestibility of the protein as a whole.
In practice, DIAAS is mainly used in food research and by specialists, less on packaging in shops. In general, the values published so far show that many animal proteins and milk protein tend to reach high DIAAS values, while individual plant protein sources can be lower. Combining different plant sources can, however, balance out this difference.
In science, DIAAS is regarded as a further development of the older method PDCAAS. The entry Biological value also offers an introduction to the topic of protein quality.
