X is the letter that comes, sometimes in multiples, in front of the letters L (large) and S (small) on our clothing. Usually only once before the S, but up to three or four in front of the L. It gets to the point they have to write it as 4X because they run out of room on the label.When it comes to the L in our clothes, we want as few of those X's as possible. The world's a funny place. When it comes to food, fast food especially, we want the L or XL, but we can't get away with that and stay with the S or XS in our clothes. So that's a good rule of thumb for ordering meals. Order the size you want your clothing size to be. Or at least in the direction your want it to go.
So, if I am an XL, and want to go back down to L or M (medium), I should keep ordering S foods until I get there.