The study was conducted at the United States National Institutes of Health by Dr Kevin Hall in collaboration with The Biggest Loser's resident doctor, Rob Huizenga, known as "Dr H".
It was published two weeks ago and blamed the weight gain on changing metabolic rates, hormone levels, and genetic predispositions.
But numerous former contestants contacted The New York Post to dispute those findings, saying the show encouraged them to take illicit drugs, starve themselves and lie about their progress.
Lezlye Donahue says being on the show was worse than living through Hurricane Katrina.
She says she was completely cut off from family and friends, and made to stay in a former psychiatric hospital with 11 other contestants in one room with no air conditioning.
"It was hot as hell, and the smell was horrible," Donahue says.
The contestants were forced to shower together with no privacy at all, and there were no working toilets so they had to squeeze into port-a-loos.
Lezlye Donahue says being on The Biggest Loser was worse than weathering Hurricane Katrina. Photo / Getty Images
Since the show, she's gained all the weight back, lost her job, suffers from depression, and owes thousands in medical bills as a result of the trauma the show put her through.
"I read that [NIH] study, and there's so much more that people don't know," she told The Post.
"There are nurses sitting there [filling people] with IV packs. I took away an eating disorder. I have nightmares about it."
A source close to the production told The Post the show supplied contestants with Adderall and other pills containing ephedra - an FDA-banned extract used for weight loss.
Joelle Gwynn was a contestant in 2008 and said she was given the pills by Dr H's assistant, "bundled up" in a brown paper bag.
"People chastise Bill Cosby for allegedly offering meds to women, but it's acceptable to do to fat people to make them lose weight. I feel like we got raped, too."
Huizenga denied the claim saying "nothing could be further than the truth" and the show has a zero tolerance policy about drugs.
Suzanne Mendonca at the end of The Biggest Loser. Photo / Getty Images
But another contestant, Suzanne Mendonca told The Post: "People would take amphetamines, water pills, diuretics, and throw up in the bathroom.
"They would take their spin bikes into the steam room to work up a sweat. I vomited every single day. Bob Harper [a trainer on the show] tells people to throw up: 'Good,' he says. 'You'll lose more calories'."
She says people were passing out in the doctor's office at the final weigh in, and five people on her season alone had to be rushed to hospital.
Mendonca says the show ruins lives: "You come back a different person. Half the people from my season have gotten divorced. The ripple effect isn't just weeks or months. It's years."
Mark Yesitis says he was "probably near death" by the end of the show. Photo / Getty Images
Police officer Mark Yesitis was on the show for season two and says he was "probably near death" by the end.
He had an operation to have his gall bladder removed and the next day ran 8km - "that's how brainwashed I was", he says.
As a cop, he says; "I've seen people's brains outside their heads ... Being on The Biggest Loser is worse".
