Anyone that has done a water fast for several days can vouch that you are not perpetually hungry. On a long fast the stomach basically shuts down. Hunger pangs do occur, but they subside after an hour or so. In my experience, three or four days or so into the fast the hunger pangs no longer occur unless you start thinking of eating. I've read that once fat reserves become exhausted then hunger pangs come back with an vengeance, as this is true starvation.