Note, I am going to provisionally withdraw a comment I made earlier in the light of some previously unseen information. I wrote:
When the intake of calories become insufficient, the body will dissolve the proteins in the muscles of the arms, legs, buttocks, heart, and elsewhere; convert those proteins into glucose in the bloodstream, and then burn a minimal fraction of the protein derived glucose as fuel while storing as much as possible into the adipose tissues with the large stores of fat already there.
I now have a conflicting source which claims muscles and protein are conserved during starvation. I don’t know which of these conflicting sources is accurate, so I’m withdrawing the comments about the muscles and protein until this conflict in sources becomes resolved.