Food Aggression?

Advising an owner to physically correct their dog while he's showing aggression, over the internet no less, is not something I'll ever condone. Far to dangerous for the humans.

Desensitizing, obedience training and a strict NILIF program is a good start and the only thing I'd advise someone to do when I haven't even met them or their dog.

A great book for the OP to read is Jean Donaldsons "MINE". It describes what resource guarding is and how (in great step by step detail) to correct it. It's an inexpensive, but invaluable little book by a fantastic author.

http://www.dogwise.com/itemdetails.cfm?ID=DTB740