The Biggest Loser (season 1) is the first season of the NBC reality television series entitled The Biggest Loser, which premiered on October 19, 2004. The show features overweight contestants competing to lose the largest percentage of their body weight and receive the title of 'Biggest Loser,' along with a $250,000 grand prize. The first season featured twelve contestants divided into two teams of six players. The teams were each led by a personal trainer, Bob Harper with the Blue Team and Jillian Michaels with the Red Team. The first season was hosted by Caroline Rhea.