[fredsir]

Your body will break down protein and fat into carbs if it isn't supplied with enough carbs. Your body has developed a mechanism to make carbs from other things because it needs carbs so badly. It would seem folly to think we should rely on this round-about disaster-mitigation mechanism instead of just supplying it with what it wants, which is partly carbs.

[mattnewport]

The premise of the keto diet is that the human body is adapted to function best when deriving most of its energy from fat (dietary or stored). This makes a certain amount of sense from an evolutionary perspective as regular meals with an abundance of easily digested refined carbs were not a feature of our ancestral evolutionary environment. The evidence that "fat-burning" is a healthier default is persuasive but not conclusive at this point I would say.

[bumby]

I think there has been some dietary research that showed people, especially those of European ancestry, have been exposed to grains long enough to have adapted. And, like with lots of nutrition information, there's counter examples of ancestral diets comprised largely of carbohydrates.

I think people need to realize there probably isn't a one-size-fits-all diet because humans are so varied genetically and well adapted to many different environments