uhh I can never gain weight -.- I try so hard too sometimes. I too ate a medium pizza by myself from Pizza Hut. What a riot, but I was really hungry. I think I went through this stage of wearing loose clothing and then all of a sudden changed into clothes that fit me nicely and my friend came up to me and was all, "OMG your'e so skinny, is something wrong with you?! ;-;"

But yeah, feeling full sucks, it usually makes me sick.