"Ketone bodies are produced by the liver under the circumstances listed above (i.e. fasting, starving, low carbohydrate diets, prolonged exercise and untreated type 1 diabetes mellitus) as a result of intense gluconeogenesis, which is the production of glucose from non-carbohydrate sources (not including fatty acids)"
https://en.wikipedia.org/wiki/Ketone_bodies
"gluconeogenesis" whoop - there's that ESSENTIAL gluco-whatever again Mr. "engineer".
How long you been running your brain on water and butter?