As it happens, I really do know two certain people: a sickly person who eats properly (according to modern nutritional ideas), and a healthy person who does not eat properly (ditto).
From this, I must conclude that your position vis a vis "good" vs. "bad" health is not objectively true in and of itself. We must conclude that this "objectivist" claim is at best incomplete.
Point blank -- are you actually claiming that "good" health is not objectively "better" than "bad" health, all other things being equal?