Bob Harper, the longtime Biggest Loser trainer who has been with NBC's popular weight-loss series since Season 1, will take on an exciting new role - and have a much bigger presence this season - when he also becomes the host of The Biggest Loser. Harper will continue to offer his training expertise to contestants at various points throughout the season. Dolvett Quince and Jennifer Widerstrom will also be returning for the 17th season, training eight contestant teams of two in an exciting return to team-versus-team competition.