Earlier quoted context omitted.
Or that's a half-understood idea some push [1], mostly looking into first order effects, and unaware of the bigger picture (except from cherry-picking this or that pro-keto study, which are themselves a dime a dozen, like most nutrition studies are). [1] Nutrition in general, is at this point scientifically half-understood. Science has tons of things it still tries to understand and needs to explain on nutrition...
The process of converting fats to ketone bodies, and the body using those ketones as energy, is a well-understood process.
Only at the high level and first order effects.
The idea that this is OK as a diet, and the tradeoffs long term, is a not-well understood process with tons of pro and con papers, as is most of nutrition science.