The Biggest Loser

The Biggest Loser is an American reality television program. It first debuted on October 19, 2004 on NBC. Originally hosted by Caroline Rhea, Alison Sweeney took over hosting duties in season four, and held that role until season seventeen, when Bob Harper took over.

The premise of the show is that a group of contestants enter the Biggest Loser Ranch and compete to become the Biggest Loser. The usually begin the season in teams, and those teams can dissolve and change over the course of the season. The last person left standing claims the title of Biggest Loser.

Format
Each week, the teams weigh-in. The team with the lowest percentage of weight lost loses the weigh-in and must vote one member off their team. In an individual circumstance, the two contestants with the lowest percentage of weight lost fall below the yellow line, and they must face the other contestants and one is voted out of the game.

There are challenges each week, for prizes ranging from communication with home, to weight loss bonuses at the weigh-in. Sometimes a contestant - or rarely a whole team - can win immunity for that week as well.