fingernails are quite high in calcium and often a good alternative.
As you lose weight move to the toe nail this is also a good stretching exercise.
Alternativley, although not my choice but Bogeys are quite chewy and harmless.
Some people on here have also chewed on dead skin from between the toes.
And in some cases earwax is often a fave, very bitter but moreish apparantly.
Still hungry??????????????x