Watch The Biggest Loser Online - The Biggest Loser Streaming: The biggest winner is 'The Biggest Loser' in this compelling new weight-loss reality drama in which two celebrity fitness trainers join with top health experts to help 12 overweight contestants transform their bodies, health and ultimately, their lives. Caroline Rhea ('Sabrina, The Teenage Witch') hosts the unscripted, one-hour series in which two competing teams follow comprehensive diet and exercise plans to undergo radical physical makeovers. Unique physical challenges, surprising alliances and irresistible temptations make the competition even tougher for the contestants, who ultimately have to decide which player gets eliminated each week. In the end, 'The Biggest Loser' becomes the biggest winner, walking away with a healthier body - and $250,000. 'The Biggest Loser' is a production of NBC Universal Television Studio, Reveille, 25/7 Productions and 3 Ball Productions. Ben Silverman (NBC's 'The Restaurant,' 'The Office (US)'), David Broome ('Jingle Ball Rock'), J.D. Roth ('NBC's '