Err, since when do obeasts eat anything plant based? Common foods, fast foods usually have a high saturated fat (from animal source) content. If you mean sugar and processed crap that isn't animal based, that's not proper nutrition either, even if it's "plant based". When I think plant based, I actually think of fruit, vegetables, legumes, nuts/seeds, whole grains but probably less of that. Anyone can include some salmon/turkey in there as well (not plant based anymore). The brain needs fat, but for the sake of the rest of the body, let that fat be good fat.