Talk:Ken Kaneki/@comment-111.68.47.161-20141130054816/@comment-10733658-20141130073746

Coffee and water are the only things Ghouls can enjoy that humans do. They cannot disgest human foods otherwise, so animals are completely out. Remember that Touka became sick from forcing herself to eat Yoriko's cooking, because not only does human food taste vile to Ghouls but their stomaches cannot digest it.

It seems the reason they have to eat human or Ghoul flesh is because these are the only things that contain RC cells. The question, obviously, is why are these the only things that have them? What exactly /are/ RC cells, and what purpose do they serve in humans who have a moderate level of them? There's definitely big questions concerning the fact that Ghouls are so reliant on these particular substance only found in humans, but no one seems to know their origin as a species.

If Ghouls could eat other things, obviously the main conflict of the series would be resolved. Given the choice between only having one dietary staple and millions of options to explore.....obviously most Ghouls would want to eat human food, with all its varieties.