There's a term I've heard for a few years now, that being orthorexia nervosa. The term is not actually recognized by the American Psychiatric Association and I don't think it should be. I think the term is misleading and causing undue tension for someone who just may be following instructions of a diet they follow.
I think a lot of vegans and whole food plant based eaters are unfairly targeted with the orthorexia label. I noticed in some plant based groups on Facebook, a few people have concerns because their family mentioned they might have the "disease".