How does the Biggest Loser Weigh In Work? ADVERTISEMENT 697 viewsMarch 20, 2013 0 M March 20, 2013 0 Comments 7 Answers ActiveVotedNewestOldest 0 Harris12 Posted 0 Comments It is based on body weight % lost during that week. The contestants with the 2 lowest BW % face elimination. You are viewing 1 out of 7 answers, click here to view all answers. Register or Login