As a responsible dog owner you do want a dog food with high quality animal proteins listed first in the list of ingredients.and not grains or artificial animal beef/chicken/lamb flavor.
No corn or GMO grain goes into my dogs as it can cause severe allergies.
High energy diets like most puppy foods, will promote rapid growth especially in large breeds. Unfortunately that might also lead to the development of orthopedic issues.
Cheaper dog foods usually list more grain and fillers than animal protein first, which means you probably will have to feed more of it to keep your dog in good shape - not to talk about the "input /output"
I feed and recommend Solid Gold .