"Is it worth losing my goal?"
When making small choices about what or how much to eat, this can refocus your eye on the big picture: the physical, psychological and lifestyle rewards versus the risks and disappointments. The answer is usually "No." Why? Because you're the one that's worth it. SO make frequent calculations. I'll look at something and say, 'I don't want it bad enough to justify ‘xxxxx’.' Or, wait and have it on the one day a week when you ease up slightly on eating constraints if you still want it then.