Thanks for your question, Louise. It seems to me that you are motivated not to overeat in this situation, and if it’s working – especially if you aren’t feeling deprived or rebellious about this – that is the proof you’re doing it right, if you see what I mean. If it ain’t broke, don’t fix it!
It seems to me there can often be an element of threat or coercion in making these changes, sort of: “if you don’t stop doing that, then…” This would be an inevitable factor in stopping smoking, and not eating (so much) junk food. It’s a matter of degree, though, and taking that on board together with some positive motivation, a good sense of free choice, and acceptance of addictive desire.