The figure I have seen is that muscle wasting drops to less than 0.2 kg per day once the body fully enter ketosis. Obviously, anyone considering a fast longer t

The figure I have seen is that muscle wasting drops to less than 0.2 kg per day once the body fully enter ketosis. Obviously, anyone considering a fast longer than a few days should do so under the supervision of a doctor who can monitor electrolyte levels etc. They can also check for the rare enzyme defect called Medium-chain acyl-CoA dehydrogenase deficiency, those with it are unable to fast safely.