jpg thumb ( 474x599 ) px right Caroline Rhea ) ) Caroline Gilchrist Rhea is a Canadian born actress and a stand up comedian . She was the original host for the NBC reality show The Biggest Loser until Alison Sweeney took her place . Caroline Gilchrist Rhea ( born April 13 , 1964 ) is a Canadian stand-up comedienne and actress who was the original host of the reality television show The Biggest Loser on NBC , until Alison Sweeney took her place after the end of the third season .