Really, the Neolithic man used to increase size by getting goosebumps!?
Well yes, back in the day (wayyyy back in the day), before central heating and the harnessing of gas and electricity, we used to have far more hair mainly for the purpose of keeping warm, but also for looking bigger! The further you go back, the closer our anatomy and physiology was to that of animals.
Like a Dog, Cat or Lion, the human would get Goosebumps when adrenaline starts to flow to increase the impression of size and bulk. Goosebumps also serve to insulate us (despite having comparitively far less hair) when small muscles under the skin contract causing the hairs to stand on end forming a warm layer of air between your skin and the atmosphere. In cave man times goosebumps caused our hairy backs to rise to attention keeping us warm, as well as making us look bigger!
Who needs protein then, just grow some hair and stuff some ice down your pants, and hey presto…you’re a beast!