I have not struggled with your particular problem, but regarding areas in which I am tempted, I find that I have much better success when I have a strategy.
First, analyze the specific circumstance which makes you feel weak. For example,do you feel most vulnerable at night while watching TV; does this situation create or strengthen the urge to snack? In other words, figure out what circumstance triggers the impulse and avoid or modify the circumstance if you can.
Second, try to replace or modify high calorie intake with other kinds of food. If you have a sweet tooth, and love sugar, try to eat something that helps satisfy your sweet tooth, but is low in fat. (My family–on the suggestion of a chef friend suggested we try frozen grapes instead of ice cream! I thought it sounded awful, but seedless grapes frozen, once you get over thinking about the ice cream can be really refreshing. We actually feel good eating this way!)
I’ve heard exercise helps a great deal (I can’t speak to this myself; I lack discipline here myself

)
Fourth, and most importantly, pray to God and ask for His help and for discipline. Ask him to show you what would be helpful to you in particular (we’re all a little different; and different things work for different people).
I admire your desire and sensitivity to bring more discipline to your life; it’s something all of us should strive for in love to God. I’ll be praying for you. Pray for me, too, in those areas of my life with which I struggle.
God bless
