Jillian Michaels didn't get along with every contestant on "The Biggest Loser" ... but, that doesn't mean she was handing out caffeine pills like a new documentary suggests -- so says one of the OG ...

Jillian Michaels, who served as a fitness trainer on the NBC reality series The Biggest Loser from 2004 to 2011, has ...

Frederickson did end up gaining back 20 pounds within a couple months of the finale. She told Us Weekly in April 2014 that ...