My two girls are 14 and 15 months old and they get breakfast at 7, a light lunch at 12 and dinner at 5. They are always ready for a meal.
I think maybe if your puppy doesn't want to eat, then maybe your feeding too much at one time. Mine get 1/4 cup for breakfast and dinner and for lunch it's just about a level tablespoon of yogurt and cottage cheese mixed together. Sometimes a raw baby carrot after that. But my girls are 7 & 8 pounds.