Such good advice already....to not take food from a dog with issues. Being the "boss" means nothing to him, so don't listen to Cesar Milan or anyone else who thinks that we are superiors to dogs in some imagined hierarchy. We are not superior at all and can't bite like a dog can. Our skin is so inferior. Our reflexes are inferior. But we do have bigger brains and that is what is needed to teach a dog behaviors we like. It is so true that no matter what rank any animal has in a social group, no animal would survive if he said to his boss, "go ahead and take my food." He wouldn't be able to reproduce and pass on his genes if he did not protect his food because he'd be dead. It is up to us to convince our dogs that we are the best thing ever because we are the food givers. They need to go through us to get all the things they love and need and those things come to them contingent on their behavior.
In addition to all the good suggestions, I'd recommend not giving your dog a bowl at all for a while....say a week or two. Hand feed by the handfuls upon his performing something for you; a sit, a down, come. Use it for reinforcing his good behavior. Never give him food within about 4 seconds of rotten behavior. Then after a time, get your bowl and hold it on your lap. Keep your hand on it and another container of food on the counter next to you. Put a handful in at a time. He should be taught, in the meantime a nice "wait" and "okay." If he lunges toward the food, stand up, turn around. Don't say anything. Try again. He can learn manners while he gets his food. Get that "okay" in quickly before he lunges at first so he learns that he must hear "okay" before he eats. Don't make him wait long at all...just a second or two for the time being and later, still not long, but a few more seconds. Feed him this way, with your hand remaining on the bowl for a week or so. While your hand is on the bowl, you possess it and are sharing. When you let go of the bowl, you have relinquished it to him. And going back to putting your hand on the bowl or getting close to it is to him, encroching on his possession.
After doing that for a while, advance to putting his bowl down on the floor empty. Have him sit and wait. Bend over (if you feel safe, otherwise, stay upright and drop) a handful of kibble in. Have him wait for his release word, "okay." If he jumps the gun, block him with your body so you're facing away from him and pick up the bowl. Try again. Put it down. "sit"...."wait"...."okay." Let him eat the big handful you put in. Stand there quietly until he just finishes and walk away about 10-15 feet. Immediately come back and put in another large handful. (sit, wait, okay) Again, when he has just eaten the last piece of kibble, walk away. Wait and see if he looks back at you as if to say, "come back and give me more food." Then return and repeat the process. Every few times, put in not only a handful of kibble, but an extra yummy treat; cheese, chicken, steak. Do this for about a week or more. Vary the location where you feed so he doesn't "own" the location either. Throw in a time or two where you hold the bowl for him.
He should come to beg you to come back to his bowl. "Please come back here and bring on the goodies." He needs to see you as the giver, never the taker. And he also needs to see that the resources (food and other valuables) come on account of his behavior. Dogs aren't particularly aware of their own behavior until they've had a sufficient history of behavior to response instances.
If you feel you might get bitten, you can use gloves. Do heed his growling warnings and don't punish growls ever. If one phase isn't working, go back to a more restrictive phase, like the hand feeding with no bowl. Don't proceed to giving him his own bowl until he is relaxed and happy with a preceeding phase. If he improves and then relapses to being worried (stiff, freezing up, stopping the chewing, watching you from the corner of his eye)...go back to hand feeding. If he gets so he's very comfortable with you coming near his food, don't slack off. Periodically, still toss in an extra yummy treat a time or two every few meals.
The most important thing to keep in mind is that if at any time you feel in danger or that any of this is beyond your confidence level to seek the help from a certified behaviorist.