I recently adopted a male lab 15 months old from a rescue centre and he is well trained obedient loving playful as you'd expect from this breed.  The only one concern is that if my son goes near him when he is eating he growls so I am a little confused.  My son is ten and is very gentle with Buddy.  At the moment I feed him when my son is not around. Any advise please.

Be very careful!  This is a warning from the dog which should be heeded!  Please do not try and take the bowl away from the dog at this stage; in order to avoid possible injury to your son (and anyone else) it is essential that you implement a programme of counterconditioning in order that the dog will be relaxed around food. 

It may also be as well NOT to give any bones, chews etc to your dog at the moment until this issue is resolved.

It is always very difficult to advise on these type of issues from a remote location as each dog is an individual and needs careful assessment as to the "level" of issue this is.  HAving said that any dog that is growling is "uncomfortable" and needs to be made more comfortable.

I would strongly recommend that you purchase Mine! A practical guide to resource guarding in dogs by Jean Donaldson or Dogs are from Neptune also by her which is more easily available where a step by step programme is laid out for you.  Alternatively or as well you may want to consult a person experienced in dealing with this problem in a LOT of dogs for practical demos.

Ideally you want to get to the stage where your dog is completely relaxed around food with everyone, which can take time, in order to avoid scrapes.

HTH