what is half a stone?
I don't binge, I am anorexic, but I was at a support group on Saturday, led by a nutritionist. She advised one of the girls who binges late at night the same thing you were just advised....to eat small amounts more frequently throughout the day to keep your blood sugar levels even and then you will be less likely to binge. I also find it very helpful to keep a food diary.
If you aren't talking about this with a therapist already, maybe you should before you get to your "target" weight. It may help sort out the feelings that lead you to your binges and help you.
Good luck