"Come on! You can do it! Don't giv- and we're done, peace!"
Once the show is over, they go back to their normal 9-to-5 lives, which typically do not include controlled diet and exercise. They cannot possibly continue a weight loss program as intense as the one on the show, and in all fairness, if you'd spent the past two months sweating through a purple T-shirt with the word "LOSER" written across it while punishingly in-shape people scream into your face about taking responsibility for your love handles, you'd probably drive straight home and order all of the pizza in the world, too, and not just because there's no longer anyone there to keep you from doing it.
"You mean to tell me that perfectly toned professional trainers don't yell at you every day? Stop making excuses."
Wait, it gets better. People who watch the show are more likely to have a negative view of physical activity. A recent study showed that the grueling way exercise is portrayed on The Biggest Loser actively discourages viewers from wanting to participate. Basically, overweight people watching the show see other overweight people crying, throwing up, and passing out during their exercise sessions while all of the thin personal trainers just yell and berate them. The end result may be inspirational, but The Biggest Loser seems to go out of its way to make the actual process of weight loss seem like thankless fucking misery.