The film begins to weave in another narrative fallacy. The fallacy being that plant protein and animal protein are really no different and if anything, plant protein is better. That is a flat out misrepresentation of scientific data. There are several reasons why plant protein may be inferior to animal protein. The first being that most plant proteins are far less bioavailable than animals proteins on the average of about 10-40% depending upon the source. [21] Further, most plant proteins are limiting in various essential (meaning we need to get them from the diet) amino acids. Rice protein is deficient in lysine, pea contains about half of the minimum methionine content, and soy, while low in methionine, has just enough not to be considered deficient. [22] Further, most plant proteins are low in leucine, the essential amino acid responsible for stimulating muscle protein synthesis. [23] Now, if you eat enough total protein from a variety of plant sources you can make up for these limitations. For example, in my PhD thesis, we found that consuming a diet containing 30% of calories from wheat protein was sufficient to maximize protein synthesis, whereas at 10% & 20% of calories from wheat protein, animal protein was superior compared to wheat. [24][25] So you CAN get maximal anabolism from vegan protein sources, but you will need more total protein, and a much more well thought out diet to do so. However, keep in mind that on average, vegans only get about 14% of their calories from protein. At these low levels of protein, the quality of protein becomes even more important. Do we need animal protein? No. But is it a superior source of essential amino acids? No question, especially when total protein in the diet is low.