Background: An optimal dietary amino acid (AA) intake is necessary for the growth of
body proteins. A new method for protein quality evaluation called digestible indispensable AA score
(DIAAS) was established. Despite that the information about dietary AA requirements are available
for different stages of life, in practical conditions, most people deal only with the dietary proteins, if
Objective: The aim of this mini-review was to analyze the protein quality of protein sources by
DIAAS and to find AA and protein dietary requirements in human nutrition.
Methods: A literature research was performed using the keyword “amino acid”, “diet”, “nutrition”,
“human”, “muscle” and “requirement” individually or all together, in Scopus, Web of Science and
Results: The optimum amount of dietary AA is necessary for AA utilization in the body and is limited
by AA which is present in the lowest amount; the surplus of other AA is not utilized in the body. Food
and Agriculture Organization reported requirements for dietary protein and AA intake for infants,
children, however for adults (over 18) for maintenance. Most of the studies which are dealing with the
dietary AA requirements in sports nutrition are aimed at the blends of AA and for branched-chain AA.
Concerning the protein quality, at this time, there is little information about the protein quality evaluated
by DIAAS method.
Conclusion: Dietary intake of high-quality protein or a blend of different proteins will provide all AA
to the body. However, studies on protein quality evaluation by DIAAS method are necessary to perform.