Jillian Michaels is stepping away from her position as one of the lead trainers on NBC's "The Biggest Loser." The 40-year-old started on the show since it first debuted in 2004. NBC announced the news in a statement, saying, "After helping thousands of contestants transform their lives and inspiring millions of viewers at home, 'The Biggest Loser' and Jillian Michaels have decided to part ways and she will not be returning for Season 16 when it airs in the fall."

This is not the first time Michaels has stepped away from the reality show. According to E! News, she left in 2006 but returned the following year and also took a brief absence in 2011, missing Seasons 12 and 13 but returned for Season 14. Michaels recently wrapped the 15th season of "The Biggest Loser," which received a little flak after one contestant lost a whopping 155 pounds.

The Season 15 winner Rachel Frederickson showed off her weight loss during the finale in February. When she started on the show, the 24-year-old voiceover artist from Los Angeles tipped the scales at 260 pounds. Seven-and-a-half months later, Frederickson weighed 105 pounds and dropped from a size 20 to a 0/2.

Everyone was shocked at the dramatic transformation and reportedly Michaels was a little upset over it. Back in April, a source told E! News that Michaels was thinking about leaving the show because of the weight loss controversy.

"She wasn't happy with how last season went," a source said at the time. "The shocking weight loss of Rachel doesn't do the brand any favors and she wants to distance her name from it."

After the season finale aired, Michaels talked to HuffPost Live about Frederickson dropping so much weight.

"We are allowed to speak with our contestants after they go home... but no one had told me, 'Hey, Rachel is very, very thin.' Bob [Harper] and I had no idea. Nobody had told us, nobody had said anything to us, so yes, I was stunned," Michaels, who was not Frederickson's trainer, said. "Obviously, I thought she had lost too much weight and I was immediately concerned and wondering how this happened, how no one had said something to me and how the checks and balances that have been put into place, in my opinion, this had fallen through those checks and balances."

According to E!, further information about Season 16 of "The Biggest Loser" will be announced at a later date.