Comment by XorNot

I won't call it common sense, but humans with highly limited technology lived and reproduced to build sophisticated civilizations in almost every biome on the planet.

Our biology is immensely adaptable, so anyone declaring you absolutely need some finely decided very specific thing in order to be "be healthy" should be treated skeptically.

With regards to protein specifically: your body doesn't trade in proteins as inputs, it trades in amino acids which cracked off the protein chains you eat. Everything else is just trying to keep the crowd of gut bacteria from making you feel uncomfortable.