CHRISTIANITY: A Question Of Gluttony?

I have an issue with a certain food (pizza) which I have been "Gluttonous" with in the past. I used to eat pizza in excess. As I understand, we are supposed to resist the spirit of gluttony because it is a sin. Does me eating only a small amount of the pizza come into accordance with not committing "Gluttony" or is simply just eating the food still count as another sin (i.e. craving / lust)?