What a puppy should eat

The dog, that was originally a carnivorous animal, has evolved turning into an omnivorous animal meaning that it not only needs a diet based on meat, but vegetables and starches as well.
Most dogs prefer canned food (because it's wet) to dry foods and it's been noticed that they enjoy hot or warm food to cold food.
Make sure to not feed your puppy the leftovers from lunch or dinner because it is not balanced or constant. A puppy's diet needs to be rich in proteins and more energetic than that of an adult dog's. Make sure that the protein you give your dog is easy to digest and good quality to ensure enough amino acids for the body. 
The quality of the protein contained in your dog's food, can be easily seen by simply watching the dog's general health. Most likely a dog that is not getting the correct amount of protein or a balanced diet will grow up with health problems that can be noticed if the dog has health problems, or if it's hair is dull etc.
Make sure to pay special attention to the amount of calcium and phosphorous you give your dog: the amount a dog's diet should have should not be under 1% of calcium and 0,8% of phosphorous in dry substances. Giving a dog an excess amount of these elements can cause the dog harm because it can cause the dog to grow with bone malformations in bigger breeds.
When getting a puppy its important to continue feeding him the same kind of food the breeder was feeding him. Keep in mind that it is difficult and on occasions stressful, for a puppy to get used to its new environment away from its mother and brothers; which is why it is important to not put the dog under further stress changing his diet abruptly. The best is to wait a few days until the puppy has become used to his new owners and then, little by little, start changing his diet.