It seems to take effort to eat past the sick feeling until you have trouble getting the food back up.
www.salon.com/1999/12/03/roach_2/ The all-time record holder would appear to be a 23-year-old London fashion model whose case was described in the April 1985 issue of Lancet. At one fateful meal, the young woman managed to put away 19 pounds of food: one pound of liver, two pounds of kidney, a half pound steak, one pound of cheese, two eggs, two thick slices of bread, one cauliflower, 10 peaches, four pears, two apples, four bananas, two pounds each of plums, carrots and grapes, and two glasses of milk. Whereupon her stomach blew up and she died.
That's just a competition meal for a competitive eater...