I am with Cherie on this one. If he attacks over food then when he doesn't like something else he might well do the same again.
When a horse comes at me because it is being fed I will give it it's feed in the bucket wrapped straight around its head, hard and I will continue to go on the attack chasing it backwards around the stable until it is sitting in its manger biting its toenails.
I will then walk out and leave it to eat its feed off the floor.
I do not tolerate any food aggression at all. I expect to be able to go I to a stable whilst a horse is eating, top up its water, skip out any droppings and that horse will continue to eat but will automatically move over without a thought of kicking or being anything else but nice and polite.
I had a horse come to me whilst the owner was on holiday. I was told to halter him before feeding to lead him whilst I put the food in the manger and lead him back to the door, go out the door and remove the halter. Oh boy, the time that would take if I had to do it with every horse!
I start the way I mean to go on and put his feed in a deep bucket, fed him in the manger at the back of the stable and he immediately started to kick. I held the bucket at arms length so he kicked it. The bucket went spinning, hit the wall, bounced beautifully, hitting him on the head - which had stopped eating when he hit the bucket. It frightened the heck out of him and as he spun away so I kicked the bucket between his legs and kept doing so as he rushed around the stable.
Next morning I walked in and fed him. One word and he moved over to allow me out and never a thought of kicking. Cured with me in one short sharp lesson. He never did it with his owner either.
I will say I was most surprised that this horse had been allowed to do this because his owner was a very experienced international event rider. She did ask of I had given him a hiding and I could in all honestly I say that I had not laid a finger on him!