Taking blood volume as 5L (a petite woman has less):-
5mmol/L of Glucose ≡ 4.5g of Glucose.
1mmol/L of Palmitic acid ≡ 1.28g of Palmitic acid.
6mmol/L of Beta-HydroxyButyric acid ≡ 3.12g of Beta-HydroxyButyric acid.
Instead of going on a ketogenic diet (with all of the health hazards associated with it), why not just add Beta-HydroxyButyric acid to your drinks?
There's a problem. All metabolic fuels produce an insulin response (from functioning pancreatic beta cells) - this is one of the ways the level of each fuel is regulated in a NFB loop. Therefore, drinking more than 3.12g of BHB (more than 2.76mL) produces a large insulin response, which results in sleepiness. Ditto for GHB.