"I don't want fans to think I feel like I'm too big for the show or that I'm seeking greener pastures. I'm so grateful to the show and so sad to leave. There were some fundamental differences [with show producers] that have existed for a while," the 40-year-old pro trainer told People.
The Biggest Loser's controversial fifteenth season ended with Rachel Frederickson, 24, winning the show after she had dropped down to a shocking 105 pounds to do so. Frederickson had lost nearly 60 percent of her body weight for the finale in February, concerning both her trainers and viewers.
"I had to take a hard look at my work," Michaels said. "I came to the conclusion that moving forward, I need to be able to have an impact on the outcome of what I do."
Another reason why the mother of two children -- a son Phoenix, 2, and daughter Lukensia, 4 -- opted to quit the show again was because she doesn't appreciate how The Biggest Loser has been portraying her as a villain. Her image on television has even worsened over time.
"In the beginning of the show it was tough love. You saw the tough, and you saw the love. [And in recent seasons,] you saw none of the relationships, none of the bonds that I build with my clients. Millions of people have this warped negative perception of me," Michaels explained.
Michaels told People that commentators have called her "abusive" and one person even quipped on TV "about what kind of mom I would be."
DuringThe Biggest Loser's most recent edition, Michaels was accused of slipping her team members caffeine pills in order to speed up their metabolisms and give them more energy for workouts. Michaels continues to insist she thought such a move was perfectly acceptable and within the show's rules.
Michaels apparently once picked up her daughter from a camp and learned someone had told little Lukensia, "I know who your mom is -- she's a cheater. I saw it on TV," which the pro trainer found very hurtful and unfortunate.
In 2006, she left the series after Season 2 due to a dispute about the show's creative direction. While she was replaced by trainer Kim Lyons forThe Biggest Loser's third edition, she subsequently returned for Season 4 and stuck with it right up until Season 12.