Well, that butter eating is not a required or integral part of the keto diet. That is just that particular doctor's own personal eating preference.
See this link which underlines that fact: "How To Do Keto Dairy-Free"
Dairy is also not a requirement for the carnivore diet. See this clip of carnivore Dr. Shawn Baker explaining that he eats very little butter: "Is Adding Butter to Your Carnivore Diet Beneficial?" (Many people on the carnivore diet use a completely dairy-free approach too.)
Speaking of butter, watch this non-keto. non-carnivore, high-carb, "Standard American Diet" guy wolf down eight sticks of butter in 3 minutes and 16 seconds!
Butter-Eating Champion
(By the way, you wouldn't want us to judge all high-carb, Standard American Diet eaters by this one guy, would you?)
