Omnivores (not meat-only carnivores) - with the gathering part of hunter-gatherer making up the most of it. Take note of how much effort hunting takes up in tribal, indiginous populations and often without much result.
Of course farming changed all that but with animals taking up much precious resource compared to crops, and their usefulness (you'd loose your fertiliser, vegetation-striper, tilling machines and dairy produce) they again weren't eaten often by the majority until the industrialisation of farming in the last 150 years or so. The same 150 years that represent the marked change in CO2 production by the human race.
I don't mean to pick on you corporeal_v001 - you have a good attitude - only the canine comment I hear repeated and repeated until it becomes true in people's minds and then used as an "I am what I am" excuse to dissolve self-responsibility.
Meat is on the menu if you choose it to be. We have the ability to choose.
Once the quasi-religious (or genuinely religious) notion of I am human therefore I eat meat is removed from the equation - I'd argue that this is solely based on culture as differing cultures to me proove - the idea that one shouldn't or can't give up meat is no different to giving up smoking. All the same attitudes and emotions to persist are there yet some manage to do so with ease.