Going vegan and eating paleo are just a couple of the various affiliations that have gone almost cult-like.
But human beings are omnivores with dietary needs that change through life.
What may work for us to live a healthy lifestyle as a younger person may not be the best lifestyle for us as we age.
So vegetarians who have been happy and healthy for years may find that they need to re-incorporate red meats back into their diets later in order to be healthy.
There is no one-size fits all diet plan.