Sorry, but you're mixing two different terms: "eat" and "stuff some food". The first one contains stuffing some food, chewing it and swalowing, then if it's something that can't be eaten in one bite you'll need to repeat. That "stuff some food" more likely exists to say, that if you were eating before the fight started you can put the last one piece in your mouth along with starting the fight, not that you can take out of your backpack a plate with dinner and eat it in the middle of a fight.
This is actualy interesting point ...
Just a question: Would it feel better if your character would only bite off one bite ... and throw away the rest?
Since it seem to me like you can totally take it that way.
