We’re pretty poorly adapted to be herbivores. We can’t eat most plants at all, and we can’t eat most parts of most plants we do eat; because we can’t digest cellulose. Some staple foods require cooking; potatoes and beans for example. Many other plants, like spinach, are much easier to digest when cooked.

We are biologically omnivores. We can digest raw meat, however Homo sapiens has always had access to fire - unflavoured, blue, fillet steak is my favourite meal - delicious!