20 years ago I would keep them on puppy food until 1 year. I switched the Rottweiler (now 4 years) from senior food 8O 8O 8O (Low protien)at 8mos. to RAW. My current Catahoula has been on RAW since 8 wks. My current thoughts on the matter is the issue is about Quailty & Quanity and not so much about carbs/fats/protien %. To clearify, feed a QUALITY food and control the QUANITY that you feed. I've always feed the pups & young dogs 20% less than recommended by the dog food companys. Now I gage by activity & how dog looks & acts.