my russian tortoise is kinda fat i too him to the vet and the vet said he was fat so i put him on a diet but he gets hungry and comes out of his house and starts banging on the walls and trying to get out to get food hes not supper fat hes just big his liver is yellow when it should be green.what should i do give in to him and give him food or is there any way i can stop him from doing that