How Much Weight Can Someone Lose In One Day?

I was re-watching the first season of The Ultimate Fighter when I thought of an interesting question.  One of the fighters on the show, Bobby Southworth, allegedly lost 20 lbs. in one day.  I've heard stories of wrestlers and mixed martial artists "cutting weight" by doing everything from sit ups in the sauna to a colon cleanse or two.  I wonder how much weight a normal sized human being can lose in one day?

First of all, let me say that I don't recommend that anyone does this.  These MMA fighters get paid handsomely to cut all of this weight, so in some cases it can be worth it for them to put their bodies through this.  It is more of a hypothetical question.  I've seen mixed martial artists like Gabe Ruediger, Travis Lutter and Jason Guida succumb to their bodies.  Travis Lutter is a MMA fighter who actually missed his target weight in a UFC Middleweight championship fight against Anderson Silva.  He said that his body simply stopped sweating, which is pretty alarming.

I am an athletic guy who weights about 220 lbs, but there is definitely some fat that I can get rid of.  I'd say that in a 24 hour period if I went all out (and had an ambulance on hand) I could probably lose 25 lbs. in one day.  You would have to go the entire day without eating and barely drinking water.  I would have to wake up at about 5:00 am and run a few miles.  Get back, hit the steam room or sauna.  In the late morning, I would go get a colon cleanse, enema or some kind of body detox .  At about noon, I would hit the exercise bike or treadmill for another hour or so, then maybe fit in a nap. 

I imagine during the afternoon, I'd have to take some kind of diuretic or laxative to get rid of whatever the colon cleanse didn't take care of.  While I was letting that take it's course, it would be more steam room and sauna followed by another kind of cardio exercise.  Maybe in the late afternoon I'd have time for an hour nap, but that's it.  I'd wind the night down by shaving my head and all hair off of my body, and more than likely another workout session.

This doesn't sound like too much fun, but I definitely think you'd be able to cut 20-30 lbs.  Once again, I wouldn't try this at home.  This is just a fun thing to think about!