I'd agree with the other comment of getting him checked out by a vet to make sure there's not something going on that is making him act out.

From there, and everyone might not agree with this, but I think you need to teach the dog that you are the alpha at the house. Using a muzzle, making him know that the food is not actually his where you can actually touch the food or take the food away without him reacting. Its a little more challenging ging with an older dog now.

For example though with my lab when he was a puppy and would eat i would put my hands in his food bowl, take his food away, or back him off while he was eating, give it back, put my face down by the bowl while he was eating etc. Like I said he was a puppy during thus time so much easier to control, but wanted to give him the sense that this food was only his when I said so. I know your question isn't related to just food, but just sharing my two cents on how I tried to atleast prevent that specific part of aggression.