Hi all have not posted in eons due to changes in work schedule etc but I do know where to go when i need help!!

Nathan will be 3 in October and all of a sudden for the past couple of months if he thinks I am going near his food dish he gets protective around it and if I put my hand down to his dish he starts growling at me!!!! Where is this coming from!!??? I can take his dishes up to clean them etc ( he is not around it at the time) and if he sees me putting it back down on his placemat he comes rushing over and starts growling at me..when i tell him NO in a start voice he growls back..What is going on??? How do I break this ???