So, it's not news that The Biggest Loser is terrible, but this article
adds at least one new reason why it's terrible to the list: I wouldn't necessarily have guessed that rapid fat loss plus intensive exercise would slow down your resting metabolic rate even more than just rapid fat loss.
"Ravussin and his team compared 12 people from The Biggest Loser with 12 people who lost similar amounts of weight via gastric bypass surgery. Because of the former’s extreme exercise regimens, the show’s contestants lost less muscle and more fat than the surgery group, but their drop in resting metabolic rate was double that of the gastric bypass group."
I found the full text of the actual study (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3387402/
). How much did the contestants resting metabolic rate drop by? An average of 504kcal/day beyond what could be accounted for by their weight loss alone. That's a substantial number of calories.
Lots more research needs to be done to figure out exactly what caused the drop in resting metabolic rate, but I think the takeaway lesson here is that significant caloric restriction plus intense exercise is a bad combo.