Carnivore, paleo, keto etc. are not “fad diets.”
The “fad” of the last century is loading our food supply with powdery SHIT like white, processed flour and sugar.
Just because we grew up on donuts, cereal and Hawaian Punch doesn’t make it normal, and the hard foods, which are natural to our species a “fad.”
Sorry, eating ONLY meat, dairy and eggs is a fad. Not even our ancestors did just these.