How much food shall i feed my 1 year old dog need?

It varies depending on the dog food, the dogs weight, and the amount of exercise they are getting. According to the bag, you would give your dog 3.5 to 5 cups of Blue Buffalo dog food per day. If he's more active, 5 cups, if he's less active, 3.5 cups. In between, adjust in between. Usually the dog food bag will tell you the recommended amount.