The best advice has been given. You keep trying till you find something that works.

Cats tends to eat food that is realy smelly. So I would definately go with quality food, but also see if they can try some really smelly food first. My vet told me about the stronger a food smell the more a cat will generally like it. They go by smell of food first. I am sure that is just a generalization and every cat is little different.

Hope this helps a little.

BTW - I did not know about cats starving themselves either. I learned something new.