Yeah, I can’t imagine eating nothing but red meat. I mean, I like a good steak, but……
I’m not a nutritionist, but I imagine it might lead to some deficiencies or something, possibly.
Not enough fiber, for one.
My grandma always said you need your fiber.
I learned about it from Quaker Oats commercials. 
Note the origin of the word ‘limey’. Subsisting on an all meat diet leads to serious nutritional deficiencies. Humans are designed to be omnivores.
I think that’s true, but are those proven facts? Serious question. I don’t know what an all meat diet will do to you. It sounds like a bad idea for sure.
I remember reading about some Arctic expeditions that suffered from trying to survive on meat rations and later perished. Not the only factor but a major one.