Who am I?

I was scared. While eating a plate of buckwheat with four slices of bread and washing it down with two cups of kefir, I stuff myself until I'm completely full and then I walk around and berate myself for overeating. I eat only once a day. And despite all this, I'm not yet completely free of excess meat.
I wouldn't want to meet such an eater in the ring. ;)
And during the game, I really just keep gulping down coffee and tea non-stop.