311 is that 97% number based on PDCAAS, which incidentally is given in fractions of 1 (the highest). That's the only way I can figure someone could come up with a number of 97. It's certainly not BV, NPU, or even PER.If you look at the PDCAAS (Protein Digestibility Corrected Amino Acid Score) then someone may be tempted to average out all the different values for beef, chicken and fish to somewhere around 97 (.97). The only way beef can actually get as high as 97, however, is with powdered, defatted beef. That's because fat and other factors affect absorption. In fact, there are different values for different cuts of meat, white and dark meat, different types of fish, etc. So, I'm just wondering where one simple number like that came from. Absorption and utilization of any nutrient, including protein, is never a simple thing. You need a Phd to even begin to understand it.I don't want to debate how much protein can be utilized at once, because quite frankly, I don't know. When I look at primary sources I continually get different answers. But I haven't found any data about how many grams of protein can or cannot be utilized at once. I have read, more than once, that smaller amounts of food are utilized more effeciently by the body than higher amounts. If there are studies (not just articles) supporting the statements about 97% efficiency, etc. I'd be interested to know, because I've never read anyone make such a simple blanket statement about protein utilization.