Whatever the reasons, ketogenic diets are the flavor of the week, and legions seem poised to toast 2017 goodbye and welcome 2018 with ketogenic Kool-Aid. I consider them dangerously misguided.
The historical case for ketogenesis — denying the body its customary fuel sources so that glucose is in short supply, and instead it metabolizes fat preferentially, and generates ketone bodies as fuel — resides in starvation. The body effectively turns to auto-digestion to sustain itself during a protracted fast. Fat and protein stores in the body are converted to fuel, and metabolism then does run on ketone bodies.