The Biggest Loser NBC launching another 'The Biggest Loser 4' casting call tour 01/09/2007 NBC has announced it is launching another nationwide open casting call tour for the fourth season of The Biggest Loser, its popular reality weight loss show. Read More RELATED NEWS 'The Biggest Loser 4's female runner-ups all still feel like winnersBill Germanakos: 'The Biggest Loser 4' victory feels "pretty amazing"Bill Germanakos wins 'The Biggest Loser 4' by losing 164 pounds TAGS: The Biggest Loser