I agree that’s why I said on my first sentence that “if you’re metabolically healthy” and also in the formula preferring LCHF or KD as your energy consumption.
The main cause of the Biggest Loser fail was the Biggest Loser diet. The macro composition of that diet is 42 to 53 percent Carbohydrates, 35 to 46 percent Protein and only 16 to 12 percent of Fat. This kind of diet does not induce ketosis thus prevents the body free access to stored fat energy.
Here’s a study about Adaptive thermogenesis in humans
But there are ways that you can minimize the impact of metabolic adaptation like taking the right diet (LCHF or KD) and taking diet breaks (the matador study)