Rosie O'Donnell slammed Jay Leno and Bob Harper on Instagram after watching Netflix docuseries about "The Biggest Loser."

Season 15 winner Rachel Frederickson lost nearly 60% of her body weight, shocking viewers and health experts at the time. Fit for TV: The Reality of The Biggest Loser, a documentary about the show's complicated legacy,

Rosie O'Donnell is never one to hold back. In an Aug. 19 Instagram post, she called out fellow TV icon Jay Leno for a mean-spirited 2009 segment from "The Tonight Show with Jay Leno," which was revisited in the new Netflix docuseries " Fit for TV: The Reality of the Biggest Loser ."

Frederickson did end up gaining back 20 pounds within a couple months of the finale. She told Us Weekly in April 2014 that she felt 125 pounds was her “perfect weight.” She also insisted that she’d lost weight “so naturally” on “The Biggest Loser.”

Erica Lugo trained 'The Biggest Loser' Season 18 winner and now, she's speaking out about her experience on the show.

The Reality of the Biggest Loser," Danny Cahill shares his experience with the show. He shares how life is for him now.

The Biggest Loser is back in the spotlight more than 20 years after it first premiered on NBC. In the new Netflix docuseries Fit for TV: The Reality of The Biggest Loser, former contestants and producers reveal the intense reality behind the success of the weight-loss reality show.

Robert Huizenga spoke about his experience on 'The Biggest Loser' on the Netflix docuseries 'Fit for TV: The Reality of The Biggest Loser'