Lean body mass loss observed in ketogenic diet studies is likely largely due to water loss associated with glycogen depletion, not contractile tissue loss.

“even i in in you know you know me i'm very critical of of uh you know zealots and nutrition um and so when i've criticized you know ketogenic diet stuff i've even still said you know in this kevin hall study well that's most of that is probably water you know because if like you said if you lose glycogen you're losing quite a bit of water with that right”