When I have an impulse to eat, or a craving I snap my wrist with the large rubber band that I wear 24/7. I snap the inside of my left wrist because it's more sensitive than the back of my wrist and because I am right handed.
This is a little trick taught to me when I was under the care of a bariatric specialist. (Aversion Therapy!) I got my rubber band off of a bunch of greens. The ones on asparagus work well too!