I got back from shopping and buying the adult food was an experience in itself! He's eating Nutro Max puppy so I decided to stick with that brand but they had a few differenct choices and I couldn't figure out which one to get. Anyway I bought the Nutro Max mini chunk. I gave Brutus one to try and he put it in his mouth and then spit it out about 20 ft.! I thought great now he hates it but he ate the one he threw and was begging for more. I put a little in his dish mixed with the puppy food and he pushed the puppy food aside and ate the other. So I guess the transition won't be as bad as I thought!