Paleo Diet mimics supposed Paleolithic eating (meat, fish, vegetables, fruits, nuts—no grains, dairy, legumes, processed foods), peaking 2013-2016 with CrossFit community adoption. Based on questionable anthropology and ignoring agricultural evolution, it nonetheless created massive market for “paleo-friendly” products before keto replaced it as trendy restrictive diet, though some adherents remain.
Sources: Paleo Diet Book Sales, CrossFit Nutrition Trends, Anthropology Critiques