This is my first post. I read your site a few days. I noticed there are a lot of topics about protein. Now, from my research, I think one would either have to eat mostly heavily refined foods or starve to have a protein deficiency but some thing that really opened my eyes on this question was an article by Dr. McDougall where he raised a point about human milk's protein content.
The stage in our lives, where our bodies grow the most rapidly (and therefore would likely be at our peak of protein needs) is our infant stage. And the exclusive food at that point in life is human milk.
Human milk has less than 7% of its calories from protein.
Here is its breaks down:
Now with its no iron content and heavy fat content I doubt that nutrient breakdown should be an adult's nutritional goal but on the protein content, if an infant, with its rapidly growing body, needs only 7% of its calories as protein, how can adult's need so much, especially non-actvie ones.
Sorry if these topic has been over-written, I just found the human milk protein content angle very interesting and saw much interest in this topic here. So, I wanted to share it, as my first post.