I don't know the answer to this, but I have mixed experiences with my axolotls.
I have 6 axolotls in total. None are completely mature yet. All get fed morning and evening.
The 3 larger axolotls (approx. 25cm) are in one tank. When they are hand fed earthworms or pieces of prawn, they will usually have an earthworm (or equivalent) and then stop. If I put another worm in front of them they don't snap at it, and sometimes will move away.
The 3 smaller ones (approx. 15cm) in the other tank can't eat a whole earthworm, so the worm gets cut in half, or prawn pieces are smaller. 2 of the juveniles (coppers) will eat the equivalent of 1 whole worm. The other (a wild type) will not only keep eating, but comes to the front of the tank, or swims to the surface, to kind of beg for food. This one has been known to eat so much that about an hour later it is sick and regurgitates the majority of the partially digested food. It has grown more than the others, but I have to limit its food to the same as the others to stop it from being sick. I am also a bit concerned that if it keeps growing so quickly it will be too big to be able to share the tank with the other 2 without them being at risk of damage, but then I also worried that if it gets too hungry the result will be the same.
I'll be interested to hear what other people have experienced.