My 3 year old daughter will not drink formula. We started out with the PKU gel. I just adopted her from Russia and they do not have access to formula that we have here. The PKU gel was great. Three spoonfuls of “pudding” consistency and you are done. Unfortunately, state and insurance does not cover the PKU gel. I adapted the same idea to her unflavored Phenylade and only use a teaspoon of water to make a pudding consistency. I flavor it with banana flavoring. Still 3-4 spoonfuls and she is done. She considers it dessert after her meals. I was concerned that I was not mixing it with enough water but our dietician said it was fine. My daughter drinks a lot of water throughout the day.