If I remember correctly don't you feed raw? Quite a few kittens I have given raw too exhibits this "wild" behavior when eating. In fact some adult cats will "go wild" when eating raw. Showing basic hunter attributes such as hunching over it in a possessive manner, growling as they eat. Picking it up and moving it away from others.. Usually with foods they really enjoy. I don't feed 100% (wish I could) and Gypsy is a doll with normal food, but given raw, you hear the growl and she takes on a protective stance and goes through the motions of stunning her food before running 3 feet and eating it.
If your not feeding raw, just feed in a more relaxed place away from others maybe in a crate until he feels secure.