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.
Sources:
mindbodygreen.com/0-17738/5-food-trends-you-think-are-healthy-but-actually-arent.html
stethnews.com/0112/foods-that-you-think-are-healthy-but-are-actually-junk/