Tami,
I've been feeding Diamond Brand food for over a year now. My adults get Diamond Naturals Chicken and Rice, as pupppies (until about a year old) I fed Diamond Brand Naturals Large Breed Puppy Lamb and Rice. It helped initially with the gas, they're kinda back to having occasional gas now. The main difference I noticed was in their coat, it totally changed, super shiney and thicker. I personally think its a great food for the price.
Jody