@Ray: I thought of Tourette's, but it didn't seem to fit with what I knew. Looking that up, it may well be what he has. It's an un-nerving thing, I tell ya.
@X: no, it's not TMJ. Yes, I've known about artificial sweeteners, hydrogenated oils, etc, etc, for over a decade. And have been fortunate to have naturally dropped interest in soda, coffee, fast food, and other things in my early to mid 20s.