Your pup is smart!
Iams, in my opinion, is not a good food.
There's quite a few higher quality foods. If you're looking to shop at Petsmart or Petco... Wellness, By Nature, Blue Buffalo, Halo, are a few to choose from.
If you're willing to go to a specialty store, I really like Orijen (they have a puppy formula), Acana, Nature's Variety, Fromm.
Good luck in your search. It took us a while. For now we have settled on Acana Grasslands and Go! Endurance, both grain-free. He does very well on both!