I had to hand feed Max his first year and play games to get him excited about food. He performed tricks and I would give him kibble off of his plate as rewards. When we went for walks, the yogurt was his reward for completing the walk. I filled his Kong with kibble and made up a silly song about "Kibble in the Kong."
He became a chow hound sometime in his second year.
Yorkies can be really silly about eating.