Brother thinks i'm bulimic

Well, my brother thinks I am bulimic because I have bad breath sometimes and whenever I have bad breath he notices. Another argument of his is that I am obsessed with weight of not only myself and others, as in celebreties - I know I am obsessed with...

weight, but I am NOT a bulimic - but no matter how many times I tell him that he doesnt believe me!
What should I do, he's like telling mom and dad and now they think I should get help and blablabla, when I DONT have a problem

print him out the defenition of bulimic.
and the medical info about it.

then shove it in his face for him to read.

if not then maybe he's just messing with you.

what brother doesnt love to do that to their sister?

yeah that could be true, but then again when he confronts me he's always so dead serious looking - but then again maybe thats a part of messing with my head! Aaaarrrggghh... brothers...