By "good portion," I mean greater than 50% of calories. See Lee.

Homo first appeared about 2.5 mya.  Our diets from then until very,  
very recently (the Neolithic) consisted of animal fats, red meat,  
fish, bugs, and nuts, fruits, and vegetables in season.

Jim

>>
>>
>>
>>
>
> A "good portion" in the form of fat and meat is not so far from what  
> the
> chimpanzees get as well, it's not the same as 30%-40% every day. 2.3  
> million
> years ago I don't think we were even called humans, homo sapiens.