I have begun weighing myself a lot because I'm trying to get to a goal weight of 175 at 5'8" (I'm currently 170). Anyways, I've noticed that I consistently lose 5-7 pounds while sleeping. I've also made sure to weigh after pissing at night and before pissing in the morning. With all this burning of calories into body heat, I can fall asleep with no sheets and no clothes. I don't do that though because it's chilly when I wake up in the morning. Sweating MIGHT play a small role, but I have a hard time believing that I could sweat pounds of water out of my system.
Has anybody else paid attention to this? I wonder if this is typical or not.