I doubt there's anything you CAN say that's enough to open her eyes and close her mouth! I'd say if you can't walk away or ignore her little lectures, or even change the subject as often as needed to get her to drop it....hmmmm....no, that'll get you fired.....<thinking> hmmm...no, that'll get you ARRESTED. <sigh> sorry, refusing to discuss food with her is the best I can do!