First, you have to identify the pattern that you keep trying to change but have had limited success, if any. If the old patterns come back, so will any lost weight. In order to change an eating-related habit, you need to create an arsenal of thoughts, words, and actions.
A thought might be that I want to weigh ____ pounds. I can do it!
A word might be “No, thank you” to yourself and others. “No thanks, I’m not hungry.”
An action? When in doubt, get out. Move you, move it. The moment will pass.