I know it can change, and the in sickness and in health part of the vow I would take seriously.
BUT
I wouldn't want to start off on the wrong foot. Somebody who never ate a vegetable in his life except "corn" (which is really a grain) and had neverending maladies wouldn't be someone I could marry, I don't think. Or chronic diabetes. Etc. For me, I think they need to be at least reasonably healthy to begin with, because things go downhill enough as it is!!!!