Its all in your mind.
You tell your mind to remind you of a time you feel good and stimulated through some part of your senses.
When this happens and you are then hungry, your mind triggers the thought process that you wish to experience in order to full fill this satisfaction. Your mind doesn't know if its good or bad, it just computes. Its your body that will give you signs as to whether it is good or not when you get sick. So if you know you have been eating it too much and you know you want to stop, then stop. Replace the hunger stimulation with something else. Find a completely different taste for lets say... a vegtable they you like. Try spinach, asparagus, carrots, or nuts, fruits sandwiches. If you are over eating.. then replace that wanting to feel good feeling with a hobby, like everytime you want to eat.. play a video game. That will turn things around.