Even if "some of the healthiest people on earth eat vegetable heavy diets" is both true and the health is a consequence of the vegetable heavy diet, that's not

Even if "some of the healthiest people on earth eat vegetable heavy diets" is both true and the health is a consequence of the vegetable heavy diet, that's not countering a point the parent made. Parent was advocating an optimal protein, low carbohydrate diet. Parent didn't say how many vegetables are in said diet. (I am on a low carb diet with plenty of veg.)