Gracile Chimps (bonobos) eat "fruits, nuts, shoots, stems, pith, leaves, roots, flowers and tubers. Mushrooms are occasionally eaten, and invertebrates such as

Gracile Chimps (bonobos) eat "fruits, nuts, shoots, stems, pith, leaves, roots, flowers and tubers. Mushrooms are occasionally eaten, and invertebrates such as termites, worms and grubs make up a small proportion of their diet." - their brains are JUST AS BIG as their carnivorous cousin species. So we have a direct comparison between two very closely related great apes that strongly indicates no evolutionary brain growth advantage of carnivorous diet. This theory seems to have a single example of an exceptionally large brained predator to claim that predation enables exceptionally large brains - humans. Humans are omnivores - traders, cookers, testers, diversifiers - some human cultures don't eat any meat - and they don't all have little heads as a result. Ive always liked butter and fatty cuts btw, (from well treated hence healthy livestock) but I'm not buying into this pop-sci that eating extra will feed my brain, or that this is what separates our kind from the dumb herbivores - meat fat feeds almost exclusively my paunch ! :]