My siberian husky was food aggressive at 7 weeks when I rescued him. He came from a large litter where there was a lot of competition for kibble, so he would defend his bowl at all cost. I began to hand feed him, praise him and reassure him. I built trust slowly with him and with in a few days he tolerated myself and other dogs to reach into his food bowl. He is now almost one years old and has never had a hint of food aggression.
Training will also help to reassure your puppy as the puppy will learn all good things come from you, such as play, treats and praise...