Both my full grown male and 10 week old female love Royal Canin mini 28 and Baby mini 30, they eat each others food and at this point I don't care which one they eat as long as they eat some kind of dry food.
Artie the male is extremely picky. Abigail eats anything!
I have tried every brand of dog food out there and it's the only one the will eat consistently. I was Lucky enough to meet/speak directly with a Royal Canin Representative at Petco some time ago in Redding, CA while visiting.
He explained why it's the best for Yorkie's, yeah he was a Rep. but he had a logical explanation.
I feel it is the Best for them and made specifically for the Breed. They are very active so what ever extra fat is in there? They can burn off through exercise!