OK so I got a new puppy and now my older dog who is one won't eat what should I do to get him to eat??

You didn't say how long it has been. First go to the dogs sticky at https://www.askmehelpdesk.com/dogs/information-articles-our-dogs-expert-labman-53153.html#post254171 I would let him go several days before trying to tempt him with rich food as outlined in the sticky.

Lavish attention on him assuring him he is still a valued member of the pack. However, it sounds like he thinks he is top dog and dislikes your decision to bring the new puppy. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at Raising Your Dog with the Monks of New Skete (http://www.dogsbestfriend.com/) For more on being top dog, see Establishing and Keeping Alpha Position (http://www.dogbreedinfo.com./topdogrules.htm) The obedience training can be part of the attention you are giving him.

Many dogs want nothing to do with a puppy. If the older dog wants nothing to do with the puppy, support it. Give the puppy a sharp ''Ut, ut, ut!'' any time it starts for the older dog and substitute a safe chew toy.

You should find some of the other sections of the dog sticky useful for the puppy.