It's a mind over matter thing in my opinion. More often than not I would spend my evenings 'grazing' despite having had a decent evening meal. Not for any reason other than it was there and I could.
It's certainly not 'easy' to SS but it becomes habit just as the eating was. And distraction works well. A nice bath, a good book, catching up with friends (writing *real* letters!!), walking the dog...it's amazing how many things you could be doing instead of munching!