Since 2004, The Biggest Loser has showcased the most shocking weight loss transformations as participants drop hundreds of pounds in just a matter of days. Because of how quickly contestants manage to slim down, the show has been under quite a bit of scrutiny.
As you might know, many past cast members have been vocal about the extreme way producers encourage them to lose weight. The diet and exercise routines are so brutal, many participants simply gain it all back once the show is over.
In 2016, Kevin Hall, a scientist at a federal research center, studied the Season 8 cast of the show to determine why some contestants struggled to keep the weight off. His findings would later change the show forever. According to his research, people who compete on the program show a drop in metabolism. In other words, the weight loss is so sudden, their bodies fight to put the weight back on.
"What was surprising was what a coordinated effect it is," Dr. Joseph Proietto told The New York Times. "The body puts multiple mechanisms in place to get you back to your weight. The only way to maintain weight loss is to be hungry all the time."
It's maybe for that reason fans were angry when Season 15 winner Rachel Frederickson debuted a shockingly thin frame at her final weigh-in, winning the competition at only 105 pounds. Many fans criticized the show for promoting anorexia.
As the show continues lingering in various controversies, its future remains uncertain, and an 18th season still hasn't been announced. However, many past winners have come to the show's defense and have kept the weight off through diligent diet and exercise.
Check out the gallery below to see what winners of The Biggest Loser look like today and see if they've kept the weight off.