Article continues below advertisementJillian Michaels is standing behind her work on The Biggest Loser. "If you say it's unrealistic, I totally agree. But if you say it's unhealthy, I'd disagree, and I have the data to back it up," Michaels, 51, defended the long-running weight loss series in an interview published with a news outlet on Monday, October 13.Article continues below advertisementJillian Michaels Claimed She Has 'Data' Source: MEGAJillian Michaels served as a trainer on 'The Biggest Loser' from 2004 to 2014. Michaels served as a trainer on The Biggest Loser from 2004 to 2014.