The fallacy of protein content

Just recently I saw a post where a guy said to a sick bodybuilder: “Eat a lot of amaranth and quinoa, so you won’t loose muscle while you’re sick”.

It’s not only about protein content. It’s also about protein quality and digestability.

Protein has been “quantified” in it’s “usefulness” for the body. This originates in the malnutrition of children in third-world countries where scientist found that some children don’t get enough protein to grow and they were looking to find out which protein is the best for the body and where to find it easily. So they searched for a method to give the protein quality a number. This number was the “biologic value” of the protein but now has been replaced by the PDCAAS (protein digestibility corrected amino acid score).

The closer a protein is to the actual needs of the body, combined with the digestibility, the higher is the PDCAAS. Despite some limitations, it is still a good tool to quantify the “usefulness” of a protein.

The table below is drawn from Wikipedia:

1 cow’s milk[3][2]
1 eggs[3][2]
1 casein (milk protein)[3]
1 soy protein[3]
1 whey (milk protein)[3]
0.99 mycoprotein[11]
0.92 beef[3][2]
0.91 soy[2]
0.893 pea protein concentrate (isolate)[12]
0.87 Sacha Inchi Powder
0.78 chickpeas and soybeans[13]
0.75 black beans[3]
0.74 tubercles[13]
0.73 vegetables[13]
0.70 other peas and legumes in general[13]
0.66 dehulled hemp seed[14]
0.64 fresh fruits[13]
0.59 cereals and derivatives[13]
0.597 cooked peas[12]
0.52 peanuts[3]
0.50 rices
0.48 dried fruits[13]
0.525 wheat bran[12]
0.42 wheat[2]
0.25 wheat gluten (food)[3]


As a rule of thumb: Meats, milk and soy are usually a good source, followed by leguminous plants, and finished by other plant proteins.

So, if a product contains e.g. lupin protein (like a protein bread here in Switzerland) it is actually not that high in useful protein as you might think. So, make the smart choice, and don’t fall for marketing tricks.

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