The pizza crusts are actually fairly small compared to the pizza.
It is still about 1.5kg of pizza I ate
A Pizza hut large margherita pizza is about 125g's a slice, that makes 1.5kg around 12 slices, 103, pull the other one, seriously just a ridiculous claim. Those don't look like very thin pan slices, but either way a Large Italian is like 95g a slice which still only puts you at around 15 slices.
THe real hardcore way to do pizzahut is eat a good 2-3 pizza's each, don't skimp on drinks and then hit the ice cream at the end after a 5-10 minute break. Did that once, surprisingly did fairly well afterwards and felt fine, and we went back another time and only just managed 1.5 pizza's each and felt like dying. Oh well. The bread on pizza takes up most space and the crust is always the thickest part so not eating them takes a decent amount of the slice away.
THough I tend not to eat pizza hut these days as I went off the taste year ago. Dominos is so much nicer, Pizza hut pan style is simply to deep fry the pizza so theres a ton of grease and not much flavour and no real bread texture. Dominos do this thing where they just cook the pizza without a half ton of oil and the Pizza's at least from most dominos i try are far less greasy than Pizza Hut.
Oh, and a picture of two trays of crusts, to me at least, doesn't in any way prove you eat all of them, its a picture. but 1.5kg pizza does not equal 103 slices, or 80 slices, or 20 slices.
I bet you'd be hard pressed to find a pizza with slices of less than 50grams a slice, so evey pretend that 103 slices at 50grams, thats over 5kg, based on that slice being half the size of a pizza hut slice, lets take that as half the calories, that would be around 150calories per 50 gram slice, so lets see you ate some 7500 calories in one sitting...... ok. Even if the crust was say 2/5 of the actual slice and you left that off, thats still 3kg of pizza, and thats IF the slices were 50grams which is highly highly unlikely. So basically, everything you said, was crap.