D.K.
It is pretty normal. When he throws a toy, take it away and put it up. Tell him he can have it back when he goes a day without throwing! When he throws food, remove the food. Be very matter of fact, explain it isn't nice and eventually it will sink in. Try also getting him some soft balls and a bucket and tell him he CAN throw these INTO THE BUCKET ONLY, however that is all. Boys especially love throwing, it isn't out of wanting attention, it just what they do. Just teach him consequences and what is okay to throw and what is not! Remove him when he does it and place him on a spot, take the toy/food away. He needs distraction more then anything at this age, he is still young.