growling

Question
i have a problem which is at a very early stage but can grow in toa seriously dangerous one. i have a 3 month old german shepherd puppy who growls if a put my hand in his food if he is eating but he is fine with me touching him while he is eating but its the food that he minds with. i know for sure that its a bluf cause when he growls a pick his food up make him sit and give him some of the food with my hand now what i want to know is that i am doing the right thing by picking his food up and making him sit and giving it to him with my hand? should i pick his food up once he is eaten half of it and feed the rest with my hand would that eliminate the behavior and another funny thing is that if i have the bowl in my hand nad he is eating the food while the bowl is in my hand and if i put my fingers in it he wouldn't even make a sound but wheni put it on the floor and then try to touch it then he starts growling but he never bites instead he starts growling and try to eat his food as fast as possible its like he is afraid of me taking the food or somethin eventhough i am the one who gives it to him in the first place

Answer
While it is important to teach a dog not to be aggressive around its food dish, that isn't the best way with the current trend toward more positive methods.  Instead, only start with part of the food.  As each time he finishes, let you touching his dish mean you are adding more.  Soon he will welcome your hands near his dish.  

''Elevation for small puppies:  Sit on the floor and gently put your hands around your pup's middle, below his front legs, and lift him up.  He is facing you.  Hold him for 15 seconds.  Repeat until he no longer struggles.  If he is past 10-12 weeks, lift his front feet off the ground, but don't pick him up.  

Cradling for small puppies:  Hold your puppy gently on his back, as you would cradle a small baby.  If he struggles, hold him firmly until he quiets for 10-15 seconds.  With larger pups, you can do this as your sit on the floor, with your pup between your legs.

Quiet lying down:  Place your pup on the floor on his side, with all 4 legs pointing away from you.  Use your hands on his neck/shoulder area and middle, to hold him in this position.  When he is quiet, praise him.  Lengthen the time that you keep him quietly in this position.  When he accepts this position well, handle his paws and muzzle, while keeping him quiet.''

The quotes mean this isn't my original work.  It is copied from my Puppy Raising Manual.  I have long used these or minor variations of them, and they are very effective.  You may want to give him a belly rub while he is on his back too.  Helps bonding.  There is a big difference between him rolling over and demanding a belly rub, and you choosing a time to roll him over and rub his belly.  The latter cements your place as pack leader.