Study shows true impact weight loss reality show had on contestants' bodies as Netflix documentary released

A study has shown the impact that a weight loss reality show had on the bodies of contestants, a topic that has been heavily discussed in a brand-new Netflix documentary.

The Netflix doc is focused on the show The Biggest Loser, an American reality show that ran for 18 seasons over 16 years.

The premise was simple: obese individuals would have the chance to win a cash prize by achieving the greatest reduction in their original body weight. And Netflix viewers reacted in shock to the documentary upon its release, saying it left their ‘jaw on the floor’.

Called Fit for TV: The Reality of The Biggest Loser, the documentary exposes many of the horrific practices on the show, from awful diets to one contestant who claimed she almost 'died' doing a task on the show.

One of the major criticisms of the show was that it wasn’t interested in genuine weight loss and instead simply wanted good TV.

Contestants were kept in isolated villas where they could only access healthy food, had expert personal trainers, and one former contestant claimed in the Netflix doc that they were made to work out as much as eight hours a day to lose weight.

A study done on contestants from the show, however, is almost as shocking as anything that took place on the Netflix documentary.

The 2017 study, conducted by the National Institute of Diabetes and Digestive and Kidney Diseases in collaboration with Towson University, examined the comparative weight loss of 14 contestants on the show versus six years later.

The documentary exposes the dark practices of the show (Netflix)

The study aimed to investigate whether contestants gained weight upon returning home or maintained their significantly reduced weights.

Of the 14 contestants investigated, it was found that all 14 had reduced metabolisms compared to the rates measured before appearing on the show.

It also found that, of the 14 contestants, all but one regained weight after the show, and one even became heavier than he was prior to going on the show.

Danny Cahill, season eight winner of the show, spoke to ABC News at the time of the publication of the study.

Cahill had lost 239 pounds on his three-week stint on the show, finishing at around 191 pounds (roughly 86kg). This was the most weight lost by a contestant ever.

Despite this, Cahill said he gained 100 pounds after his time on the show, even going as far as to say that due to his lowered metabolism, he had to work out three or four times more than before his appearance on the show.

Cahill appeared on the Netflix show to talk about how he had regained the weight he lost (NBC)

Cahill said the study had inspired him after feeling a great degree of shame from his weight regain, as he said: "When we found this out we were like, 'Okay, some of it is not our fault.' It is our responsibility, but some of it has to do with this science."

In response to the study's findings, the producers of The Biggest Loser told ABC News: "We have comprehensive procedures and support systems in place which we routinely re-evaluate to ensure all contestants receive the best care possible.

"The lead medical doctor on the show, who has worked with the National Institutes of Health on initiatives in the past relating to ‘The Biggest Loser,’ has been made aware of this most recent study and is in the process of evaluating its findings."

The show was cancelled by NBC in 2016, before being brought back for one final season in 2020 on the USA Network.

Fit for TV: The Reality of The Biggest Loser is available to watch on Netflix now.