The reason I'm asking this has to do with something called PDCAAS—the Protein Digestibility Corrected Amino Acid Score. This is a little-known but important part of nutrition labeling in the United States, and especially if you're nutrition-conscious. The % Daily Value (%DV) that you see on nutrition labels tells you the protein content in grams out of the recommended daily amount of 50 grams. Simple enough, right? It's simple in theory, but the reality is that the %DV is graded by the bioavailability of the protein. This means that if something says 30 grams of protein, it might actually have 20 that are bioavailable. If it's a high-quality protein source, then that 30 grams of protein will be 60% of the recommended value, but if it's low-quality, and thus not very bioavailable, it'll be a smaller percentage. To figure out how this is calculated, we have to turn to the Code of Federal Regulations. If you'd like to follow along, please turn to 21 CFR 101.9(c)(7)(ii). It reads: "The 'corrected amount of protein (gram) per serving' for foods represented or purported for adults and children 1 or more years of age is equal to the actual amount of protein (gram) per serving multiplied by the amino acid score corrected for protein digestibility. If the corrected score is above 1.00, then it shall be set at 1.00." The method for determining this protein bioavailability measure is detailed in the "Report of the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation" and the bioavailability is scaled relative to casein protein. Now, unfortunately, companies are not required to list the %DV even if they have to list the protein content—as assessed by nitrogen analysis— if the product does not claim to be "high protein" or it's not marketed for infants or children ages 1-3. So, OK, why am I asking for the %DV? Why can't I just use the provided grams of protein? I'm asking for the %DV because it's not listed on the product—a serious red flag—and I'm not able to use the grams of protein listed on the label, because I don't know how high-quality the protein in the product is. Consider Beyond Meat as an example. Beyond Meat 3.0 had high-quality protein: a 20g serving was 40% of the recommended daily amount and a 40g serving was 80%. Simple enough! But Beyond Meat 4.0 is worse. Where 21g of protein should be 42% of the Daily Value, it's 34% instead, and that 34% is rounded up—42 grams of the protein in Beyond Meat 4.0 is really only 67% of the Daily Value, because the protein is not very high-quality! Now it should be clear why I'm asking. Tons of companies hype their products as high-protein, when the reality is that the protein in their products is not very high-quality and the bioavailability could be poor. I want to know, and customers deserve to know, what the protein quality is like in every product they're presented with. If these thirty grams of protein in a delicious sparkling water are not high-quality, then I'm going to be a lot less happy about this product than I would be otherwise. But even though I might end up unhappy about the product, I feel I still deserve to know the truth. Sources: P.S. The 50 grams of protein thing is for adults and children four and older. It's 11 grams for infants through twelve months, 13 grams for children 1-3, and 71 grams for pregnant and lactating mothers.