Craving food is tied to a bodily sensation. When a thorn pricks you get pain to avoid it, similarly sensations when your body signals you need fast food or a particular type.
When looking at bodily sensations try to isolate the particular sensation and develop equanimity and difference towards it. Sensations tied to different types of food also slightly varied. When you body the low in sugar the sensation is different from when craving to something savory.
Also when hungry you get another sensation. Do the same for the sensations tied to how your body signals that you are hungry or need to eat.
Our mind and body is programed to react to these sensations or signals your body generate. To take back control you have to have mastery over the bodily signals. So instead of developing willpower not to eat, use the will power to master the bodies signalling mechanism, to achieve the same through sensations / bodily signals as proxy.
This is easy said than done. Go get the real hang of it you will have to do a meditation course which train you to observe bodily sensation. You can try one of:
Also you can try "The perception of loathsomeness in food" meditation. You should not over do this of you might get anorexia.