Your answer to why are we eating so much makes so much sense. I remember reading somewhere that we as humans weren't designed to eat meat, and if you think about it we have nothing in our bodies that lets us hunt, I mean our bodies cant even process raw meat.

I remember while traveling in Ecuador I visited the Pululahua Vulcano where there's actual people living inside its crater. They in their majority live in a raw fruits and vegetables diet, I remember an old man (he told us to be 90 years old) going up trough the ladder of the vulcano with his harvest on his back, he looked healthier than me.

I'll start investigating fasts after this post.