The net protein utilization (NPU) is the percentage of ingested nitrogen that is retained in the body.
Certain foodstuffs, such as eggs or milk, rate as 1 on an NPU chart.
[4] Another closely related quantity is the net postprandial protein utilization (NPPU), which is the maximum potential NPU of a dietary protein source under ideal conditions.
[1]: 12 The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is a more modern rating for determining protein quality, and the current ranking standard used by the FDA.
The Digestible Indispensable Amino Acid Score (DIAAS) is a protein quality method, proposed in March 2013 by the Food and Agriculture Organization[5] to replace the current protein ranking standard, the Protein Digestibility Corrected Amino Acid Score (PDCAAS).