Jillian Michaels (born Jillian Leigh McKarus; February 18, 1974) is an American personal trainer, businesswoman, author and television personality from Los Angeles, California. Michaels is best known for her appearances on NBC, particularly The Biggest Loser. She is also known for her appearance on the talk show The Doctors. In fall 2015, she hosted and co-judged a series on Spike titled Sweat, INC. In January 2016, her reality television series Just Jillian premiered on E!.