i feed chili the sport 26/16 mainly because he had surgery and isnt that active(house dog right now). my thought is that will help him not get fat, but really I have no idea. Chili has eaten many different brands of food and I cant see a difference honestly...all his lab tests have always surprised the vets saying they looked perfect...I suppose it all depends on how active your dog is...kinda like human athletes need more and dieters need less