Thank you for saying this. The PDCAAS shows the digestible properties of different protein sources. It would be a good multiplicative factor for the X-Axis to make the sources comparable, since Cow's Milk, Chicken, Egg, Whey, Casein, Tuna and Soy Protein (Isolate) have a score of 1 while Lentils, Tofu, Rice and Wheat have roughly 0,5.

That means you need to eat (and buy and cook) twice the amount of the latter to gain roughly the amount of actionable protein of the former.