I wouldn't bash a Ketogenic diet per se, but it's recoomendable for people who compete in muscle sports, but for most people I'd reccomend between 20-30g Carbs becasue Carbs help stabilise blood sugar, provide energy and affect positive hormones like relaxation type hormones.
If energy expenditure was higher then energy intake from things like Carbs, the body could source additional energy from fat, but in some case perhaps protein and may resort to muscle burning too.
The body can convert around 40% of Protein intake into Glycogen, the stored form of glucose, particularly in muscles.
You might find it beneficial to find my sticky topic on Cholesterol and see if there is anything you might find useful, to glean from it
Good luck whatever happens and let us know what happens won't you, becasue we may be able to learn something from your experience(s).