I like watching the show for motivation, but I do know that their results aren't realistic. Strict calorie restriction while doing 6 hours of exercise every day is grueling on the body. Muscle weighs more than fat--and I do think that those who stayed the longest lost just as much of their muscle mass as they did fat. That and every single "last chance workout" = getting as dehydrated as possible before stepping on the scales. Burning 1,000 calories before a weigh-in isn't going to tip the scales, but losing the amount of water you lose burning 1,000 might.
Still, watching the rapid progression from obese to normal weight over the course of the show inspires me, even if it's not realistic.
If I had a TV at my disposal, I'd be watching that show tonight. For now, I'll have to settle for downloading it off the 'net. I'm going home to fetch my TV this weekend...so I'll be able to watch then!