OK...I've always been under the impression that the brain can only use glucose for fuel...so that even when the rest of the body uses ketone bodies (when in ketosis...doing atkins, or during starvation) there still needs to be a modicum of gluconeogenesis (to produce glucose) in order for the brain to function...
My physiology professor begs to differ...in fact basically called me an idiot in front of the class for suggesting it...but this is what i remember from my undergrad nutrition degree...am i forgetting something?? or am i just an idiot? (don't answer that second one)