I do see that restaurants have enormous dinner time portions compared to their lunch counter parts, I'm talking a 400-500 calorie difference. I can hardly finish my meal if I go out to eat for dinner.  And I thought it was 2 closed fists, or something like 3 cups worth of things.  wait, found something: "Generally, human stomachs have a volume about one liter, which is a little more than one quart. Since the stomach has the ability to expand, it can hold much more food. The human stomach can be distended up to four liters, which is more than one gallon."  http://hypertextbook.com/facts/2000/JonathanCheng.shtml