The Biggest Loser features obese people competing to win a cash prize by losing the highest percentage of weight relative to their initial weight.
| Title | Air Date | Duration | ||
|---|---|---|---|---|
| Season 1 | Episode 1 | Episode 1: Pilot | 2004-10-19 | 60 min |
| Season 1 | Episode 2 | Episode 2 | 2004-10-26 | 60 min |
| Season 1 | Episode 3 | Episode 3 | 2004-11-09 | 60 min |
| Season 1 | Episode 4 | Episode 4: Red and Blue Teams Go to New Heights | 2004-11-16 | 60 min |
| Season 1 | Episode 5 | Episode 5: A Team Lightens Up Through Elimination | 2004-11-23 | 60 min |
| Season 1 | Episode 6 | Episode 6: Teams Trek to the Beach for a Challenge | 2004-11-30 | 60 min |
| Season 1 | Episode 7 | Episode 7: Biking Challenge | 2004-12-07 | 60 min |
| Season 1 | Episode 8 | Episode 8: Playing It Close to the Vest | 2004-12-14 | 60 min |
| Season 1 | Episode 9 | Episode 9: A Look Back Special | 2004-12-21 | 60 min |
| Season 1 | Episode 10 | Episode 10: Final Weigh-In At The Ranch | 2005-01-04 | 60 min |
| Season 1 | Episode 11 | Episode 11: Season Finale | 2005-01-11 | 60 min |
| Season 1 | Episode 12 | Episode 12: It Isn't Over Until It's Over | 2005-01-18 | 60 min |
| Season 2 | Episode 1 | Season Two Begins | 2005-09-13 | 60 min |
| Season 2 | Episode 2 | Straight and Narrow is Tough | 2005-09-20 | 60 min |
| Season 2 | Episode 3 | Hurt Bodies and Feelings | 2005-09-27 | 60 min |
| Season 2 | Episode 4 | What Happens in Vegas Buffets in Vegas | 2005-10-04 | 60 min |
| Season 2 | Episode 5 | Losing Teammates Instead of Weight Drags Down One Team | 2005-10-11 | 60 min |
| Season 2 | Episode 6 | High Anxiety | 2005-10-18 | 60 min |
| Season 2 | Episode 7 | Let's Do the Twist! | 2005-10-25 | 60 min |
| Season 2 | Episode 8 | Fancy Footwork from Pedicures to Pedicabs | 2005-11-01 | 60 min |
| Season 2 | Episode 9 | Jump Start | 2005-11-08 | 60 min |
| Season 2 | Episode 10 | Last One in the Pool is a Winner | 2005-11-15 | 60 min |
| Season 2 | Episode 11 | Scary Scale | 2005-11-22 | 60 min |
| Season 2 | Episode 12 | Season Two Finale | 2005-11-29 | 60 min |
| Season 3 | Episode 1 | Season Premiere | 2006-09-20 | 60 min |
| Season 3 | Episode 2 | The Biggest Loser Goes to the Beach | 2006-09-27 | 60 min |
| Season 3 | Episode 3 | Cruise Week | 2006-10-04 | 60 min |
| Season 3 | Episode 4 | Free Pass | 2006-10-11 | 60 min |
| Season 3 | Episode 5 | Gym Gone | 2006-10-18 | 60 min |
| Season 3 | Episode 6 | Tough Choices | 2006-10-25 | 60 min |
| Season 3 | Episode 7 | Duos | 2006-11-01 | 60 min |
| Season 3 | Episode 8 | They're Back | 2006-11-08 | 60 min |
| Season 3 | Episode 9 | Individuals | 2006-11-15 | 60 min |
| Season 3 | Episode 10 | All About the Holidays | 2006-11-29 | 60 min |
| Season 3 | Episode 11 | Back to School | 2006-12-06 | 60 min |
| Season 3 | Episode 12 | The Final Four | 2006-12-06 | 60 min |
| Season 3 | Episode 13 | Season Finale Live! | 2006-12-13 | 60 min |
| Season 4 | Episode 1 | Back to Basics | 2007-09-11 | 60 min |
| Season 4 | Episode 2 | The Secret Black Team is Revealed! | 2007-09-18 | 60 min |
| Season 4 | Episode 3 | The Pressure of Temptation | 2007-09-25 | 60 min |
| Season 4 | Episode 4 | Bidding Wars | 2007-10-02 | 60 min |
| Season 4 | Episode 5 | Surprise Getaway | 2007-10-09 | 60 min |
| Season 4 | Episode 6 | Lively Beach Competition | 2007-10-16 | 60 min |
| Season 4 | Episode 7 | Weigh-In Shocker | 2007-10-23 | 60 min |
| Season 4 | Episode 8 | Most Emotional Elimination So Far of the Season | 2007-10-30 | 60 min |
| Season 4 | Episode 9 | Biggest Losers Go Green | 2007-11-06 | 60 min |
| Season 4 | Episode 10 | A Taste of Home | 2007-11-13 | 60 min |
| Season 4 | Episode 11 | Memorable Makeovers | 2007-11-20 | 60 min |
| Season 4 | Episode 12 | Viewers Choose the Challenge | 2007-11-27 | 60 min |
| Season 4 | Episode 13 | A Slice of Temptation | 2007-12-04 | 60 min |
| Season 4 | Episode 14 | Five Remaining Players Compete for Spot on Finale | 2007-12-11 | 60 min |
| Season 4 | Episode 15 | Biggest Loser Revealed In Season Finale | 2007-12-18 | 60 min |
| Season 5 | Episode 1 | They Got Fat Together, Can They Get Thin Together? | 2008-01-01 | 60 min |
| Season 5 | Episode 2 | Contestants Face Barbecue Temptation and Giant Seesaw Challenge! | 2008-01-08 | 60 min |
| Season 5 | Episode 3 | Tensions Run High As This Week's Challenge Causes Rifts Among Players | 2008-01-15 | 60 min |
| Season 5 | Episode 4 | One Outcast Duo Squares Off Against All the Rest | 2008-01-22 | 60 min |
| Season 5 | Episode 5 | Surprise Escalator Challenge Changes the Game Forever | 2008-01-29 | 60 min |
| Season 5 | Episode 6 | Celebrity Chef Rocco DiSpirito Guest Stars | 2008-02-05 | 60 min |
| Season 5 | Episode 7 | Special Guest Appearance by Jillian's Mom | 2008-02-12 | 60 min |
| Season 5 | Episode 8 | Contestants Reunited With Loved Ones | 2008-02-19 | 60 min |
| Season 5 | Episode 9 | One Team Surprised With Trip to Vegas | 2008-02-26 | 60 min |
| Season 5 | Episode 10 | Contestants Tackle One of the Biggest Challenges in Show's History | 2008-03-04 | 60 min |
| Season 5 | Episode 11 | All Contestants Return to Ranch in Surprise Twist | 2008-03-11 | 60 min |
| Season 5 | Episode 12 | Contestants Made Over by Fashion Guru Tim Gunn | 2008-03-18 | 60 min |
| Season 5 | Episode 13 | Competition Heats Up With Only Six Contestants Left | 2008-03-25 | 60 min |
| Season 5 | Episode 14 | Last Five Contestants Get Surprise Trip to Australia | 2008-04-01 | 60 min |
| Season 5 | Episode 15 | Surprise Game-Changing Twist in Last Episode Before Live Finale | 2008-04-08 | 60 min |
| Season 5 | Episode 16 | "Biggest Loser" Revealed in Season Finale | 2008-04-15 | 60 min |
| Season 6 | Episode 1 | Husband-Wife and Parent-Child Teams | 2008-09-16 | 60 min |
| Season 6 | Episode 2 | Chef Rocco DiSpirito | 2008-09-23 | 60 min |
| Season 6 | Episode 3 | Grand Canyon | 2008-09-30 | 60 min |
| Season 6 | Episode 4 | Toughest Challenge Yet | 2008-10-07 | 60 min |
| Season 6 | Episode 5 | Surprising Weigh-In | 2008-10-08 | 60 min |
| Season 6 | Episode 6 | Longest Challenge Ever | 2008-10-14 | 60 min |
| Season 6 | Episode 7 | Unusual Workouts | 2008-10-21 | 60 min |
| Season 6 | Episode 8 | Record Weigh-In | 2008-10-28 | 60 min |
| Season 6 | Episode 9 | Week of Surprises | 2008-11-11 | 60 min |
| Season 6 | Episode 10 | '80s Week | 2008-11-18 | 60 min |
| Season 6 | Episode 11 | Thanksgiving week | 2008-11-25 | 60 min |
| Season 6 | Episode 12 | Makeover Episode | 2008-12-02 | 60 min |
| Season 6 | Episode 13 | Final Four | 2008-12-09 | 60 min |
| Season 6 | Episode 14 | Finale! | 2008-12-16 | 60 min |
| Season 7 | Episode 1 | Season Premiere | 2009-01-06 | 60 min |
| Season 7 | Episode 2 | Bob Freaks Out | 2009-01-13 | 60 min |
| Season 7 | Episode 3 | Temptations Suck | 2009-01-20 | 60 min |
| Season 7 | Episode 4 | Super Bowl | 2009-01-27 | 60 min |
| Season 7 | Episode 5 | Home Team Weigh-In | 2009-02-03 | 60 min |
| Season 7 | Episode 6 | 100th Episode | 2009-02-10 | 60 min |
| Season 7 | Episode 7 | Gym Keys | 2009-02-17 | 60 min |
| Season 7 | Episode 8 | Black and Blue Part 1 | 2009-02-24 | 60 min |
| Season 7 | Episode 9 | Black and Blue Part 2 | 2009-02-25 | 60 min |
| Season 7 | Episode 10 | Chef Rocco DiSpirito | 2009-03-03 | 60 min |
| Season 7 | Episode 11 | 24 Hour Fitness Relay Race | 2009-03-10 | 60 min |
| Season 7 | Episode 12 | Contestants Go Home for a Week and Complete Half-Marathons | 2009-03-17 | 60 min |
| Season 7 | Episode 13 | The Teams Split Up | 2009-03-24 | 60 min |
| Season 7 | Episode 14 | Blast from the Past | 2009-03-31 | 60 min |
| Season 7 | Episode 15 | Only One Vote | 2009-04-07 | 60 min |
| Season 7 | Episode 16 | The Makeover Episode | 2009-04-14 | 60 min |
| Season 7 | Episode 17 | Trivia Quiz | 2009-04-21 | 60 min |
| Season 7 | Episode 18 | Contestants Get to Train Their Trainers! | 2009-04-28 | 60 min |
| Season 7 | Episode 19 | Running a Full Marathon! | 2009-05-05 | 60 min |
| Season 7 | Episode 20 | Finale | 2009-05-12 | 60 min |
| Season 7 | Episode 21 | Finale Part 2 | 2009-05-12 | 60 min |
| Season 8 | Episode 1 | Week 1 | 2009-09-15 | 60 min |
| Season 8 | Episode 2 | Week 2 | 2009-09-22 | 60 min |
| Season 8 | Episode 3 | Week 3 | 2009-09-29 | 60 min |
| Season 8 | Episode 4 | Week 4 | 2009-10-06 | 60 min |
| Season 8 | Episode 5 | Week 5 | 2009-10-13 | 60 min |
| Season 8 | Episode 6 | Week 6 | 2009-10-20 | 60 min |
| Season 8 | Episode 7 | Week 7 | 2009-10-27 | 60 min |
| Season 8 | Episode 8 | Week 8 | 2009-11-03 | 60 min |
| Season 8 | Episode 9 | Week 9 | 2009-11-10 | 60 min |
| Season 8 | Episode 10 | Week 10 | 2009-11-17 | 60 min |
| Season 8 | Episode 11 | Week 11 | 2009-11-24 | 60 min |
| Season 8 | Episode 12 | Week 12 | 2009-12-01 | 60 min |
| Season 8 | Episode 13 | Finale (Week 13) | 2009-12-08 | 60 min |
| Season 9 | Episode 1 | Week 1 | 2010-01-05 | 60 min |
| Season 9 | Episode 2 | Week 2 | 2010-01-12 | 60 min |
| Season 9 | Episode 3 | Week 3 | 2010-01-19 | 60 min |
| Season 9 | Episode 4 | Week 4 | 2010-01-26 | 60 min |
| Season 9 | Episode 5 | Week 5 | 2010-02-02 | 60 min |
| Season 9 | Episode 6 | Week 6 | 2010-02-09 | 60 min |
| Season 9 | Episode 7 | Week 7 | 2010-03-02 | 60 min |
| Season 9 | Episode 8 | Week 8 | 2010-03-09 | 60 min |
| Season 9 | Episode 9 | Week 9 | 2010-03-16 | 60 min |
| Season 9 | Episode 10 | Week 10 | 2010-03-23 | 60 min |
| Season 9 | Episode 11 | Week 11 | 2010-03-30 | 60 min |
| Season 9 | Episode 12 | Week 12 | 2010-04-06 | 60 min |
| Season 9 | Episode 13 | Week 13 | 2010-04-13 | 60 min |
| Season 9 | Episode 14 | Week 14 | 2010-04-20 | 60 min |
| Season 9 | Episode 15 | Week 15 | 2010-04-27 | 60 min |
| Season 9 | Episode 16 | Week 16 | 2010-05-04 | 60 min |
| Season 9 | Episode 17 | Week 17 | 2010-05-11 | 60 min |
| Season 9 | Episode 18 | Week 18 | 2010-05-18 | 60 min |
| Season 9 | Episode 19 | Week 19 - Finale | 2010-05-25 | 60 min |
| Season 10 | Episode 1 | Week 1 | 2010-09-21 | 60 min |
| Season 10 | Episode 2 | Week 2 | 2010-09-28 | 60 min |
| Season 10 | Episode 3 | Week 3 | 2010-10-05 | 60 min |
| Season 10 | Episode 4 | Week 4 | 2010-10-12 | 60 min |
| Season 10 | Episode 5 | Week 5 | 2010-10-19 | 60 min |
| Season 10 | Episode 6 | Week 6 | 2010-10-26 | 60 min |
| Season 10 | Episode 7 | Week 7 | 2010-11-02 | 60 min |
| Season 10 | Episode 8 | Week 8 | 2010-11-09 | 60 min |
| Season 10 | Episode 9 | Week 9 | 2010-11-16 | 60 min |
| Season 10 | Episode 10 | Week 10 | 2010-11-23 | 60 min |
| Season 10 | Episode 11 | Week 11 | 2010-11-30 | 60 min |
| Season 10 | Episode 12 | Week 12 | 2010-12-07 | 60 min |
| Season 10 | Episode 13 | Week 13 | 2010-12-14 | 60 min |
| Season 11 | Episode 1 | Week 1 | 2011-01-04 | 60 min |
| Season 11 | Episode 2 | Week 2 | 2011-01-11 | 60 min |
| Season 11 | Episode 3 | Week 3 | 2011-01-18 | 60 min |
| Season 11 | Episode 4 | Week 4 | 2011-01-25 | 60 min |
| Season 11 | Episode 5 | Week 5 | 2011-02-01 | 60 min |
| Season 11 | Episode 6 | Week 6 | 2011-02-08 | 60 min |
| Season 11 | Episode 7 | Week 7 | 2011-02-15 | 60 min |
| Season 11 | Episode 8 | Week 8 | 2011-02-22 | 60 min |
| Season 11 | Episode 9 | Week 9 | 2011-03-01 | 60 min |
| Season 11 | Episode 10 | Week 10 | 2011-03-08 | 60 min |
| Season 11 | Episode 11 | Week 11 | 2011-03-15 | 60 min |
| Season 11 | Episode 12 | Week 12 | 2011-03-22 | 60 min |
| Season 11 | Episode 13 | Week 13 | 2011-03-29 | 60 min |
| Season 11 | Episode 14 | Week 14 | 2011-04-05 | 60 min |
| Season 11 | Episode 15 | Week 15 | 2011-04-12 | 60 min |
| Season 11 | Episode 16 | Week 16 | 2011-04-19 | 60 min |
| Season 11 | Episode 17 | Week 17 | 2011-04-26 | 60 min |
| Season 11 | Episode 18 | Week 18 "Makeover Week" | 2011-05-03 | 60 min |
| Season 11 | Episode 19 | Week 19 | 2011-05-10 | 60 min |
| Season 11 | Episode 20 | Week 20 | 2011-05-17 | 60 min |
| Season 11 | Episode 21 | Week 21 | 2011-05-24 | 60 min |
| Season 12 | Episode 1 | Week 1 | 2011-09-20 | 60 min |
| Season 12 | Episode 2 | Week 2 | 2011-09-27 | 60 min |
| Season 12 | Episode 3 | Week 3 | 2011-10-04 | 60 min |
| Season 12 | Episode 4 | Week 4 | 2011-10-11 | 60 min |
| Season 12 | Episode 5 | Week 5 | 2011-10-18 | 60 min |
| Season 12 | Episode 6 | Week 6 | 2011-10-25 | 60 min |
| Season 12 | Episode 7 | Week 7 | 2011-11-01 | 60 min |
| Season 12 | Episode 8 | Week 8 | 2011-11-08 | 60 min |
| Season 12 | Episode 9 | Week 9 | 2011-11-15 | 60 min |
| Season 12 | Episode 10 | Week 10 | 2011-11-22 | 60 min |
| Season 12 | Episode 11 | Week 11 - Makeover Week | 2011-11-29 | 60 min |
| Season 12 | Episode 12 | Week 12 | 2011-12-06 | 60 min |
| Season 12 | Episode 13 | Week 13 - Finale | 2011-12-13 | 60 min |
| Season 13 | Episode 1 | Week 1 | 2012-01-03 | 60 min |
| Season 13 | Episode 2 | Week 2 | 2012-01-10 | 60 min |
| Season 13 | Episode 3 | Week 3 | 2012-01-17 | 60 min |
| Season 13 | Episode 4 | Week 4 | 2012-01-24 | 60 min |
| Season 13 | Episode 5 | Week 5 | 2012-01-31 | 60 min |
| Season 13 | Episode 6 | Week 6 | 2012-02-07 | 60 min |
| Season 13 | Episode 7 | Week 7 | 2012-02-14 | 60 min |
| Season 13 | Episode 8 | Week 8 | 2012-02-21 | 60 min |
| Season 13 | Episode 9 | Week 9 | 2012-02-28 | 60 min |
| Season 13 | Episode 10 | Week 10 | 2012-03-06 | 60 min |
| Season 13 | Episode 11 | Week 11 | 2012-03-13 | 60 min |
| Season 13 | Episode 12 | Week 12 | 2012-03-20 | 60 min |
| Season 13 | Episode 13 | Week 13 | 2012-03-27 | 60 min |
| Season 13 | Episode 14 | Week 14 | 2012-04-03 | 60 min |
| Season 13 | Episode 15 | Week 15 | 2012-04-10 | 60 min |
| Season 13 | Episode 16 | Week 16 | 2012-04-17 | 60 min |
| Season 13 | Episode 17 | Week 17 | 2012-04-24 | 60 min |
| Season 13 | Episode 18 | Week 18 - Finale | 2012-05-01 | 60 min |
| Season 14 | Episode 1 | We're Back ... And So Is Jillian | 2013-01-06 | 60 min |
| Season 14 | Episode 2 | Keep Moving | 2013-01-07 | 60 min |
| Season 14 | Episode 3 | Cut The Junk | 2013-01-14 | 60 min |
| Season 14 | Episode 4 | Pay It Forward | 2013-01-21 | 60 min |
| Season 14 | Episode 5 | Waist & Money | 2013-01-28 | 60 min |
| Season 14 | Episode 6 | Lead By Example | 2013-02-04 | 60 min |
| Season 14 | Episode 7 | Tough Love | 2013-02-11 | 60 min |
| Season 14 | Episode 8 | Work Together | 2013-02-18 | 60 min |
| Season 14 | Episode 9 | Face Your Fears | 2013-02-25 | 60 min |
| Season 14 | Episode 10 | Make a Difference (Makeover Week) | 2013-03-04 | 60 min |
| Season 14 | Episode 11 | Down To The Wire | 2013-03-11 | 60 min |
| Season 14 | Episode 12 | Live Finale | 2013-03-18 | 60 min |
| Season 15 | Episode 1 | Second Chances | 2013-10-15 | 60 min |
| Season 15 | Episode 2 | A Game of Chance | 2013-10-22 | 60 min |
| Season 15 | Episode 3 | The Auction | 2013-10-29 | 60 min |
| Season 15 | Episode 4 | Trick or Treat | 2013-11-05 | 60 min |
| Season 15 | Episode 5 | The Cook-Off | 2013-11-12 | 60 min |
| Season 15 | Episode 6 | Remember Who You Are | 2013-11-19 | 60 min |
| Season 15 | Episode 7 | Thanksgiving | 2013-11-26 | 60 min |
| Season 15 | Episode 8 | Take a Trainer Home | 2013-12-03 | 60 min |
| Season 15 | Episode 9 | Work Week | 2013-12-10 | 60 min |
| Season 15 | Episode 10 | Down to Singles | 2013-12-17 | 60 min |
| Season 15 | Episode 11 | Who Gets a Second Chance Back? | 2014-01-07 | 60 min |
| Season 15 | Episode 12 | Winter Olympics | 2014-01-14 | 60 min |
| Season 15 | Episode 13 | Makeover Week | 2014-01-21 | 60 min |
| Season 15 | Episode 14 | Triathlon | 2014-01-28 | 60 min |
| Season 15 | Episode 15 | Finale | 2014-02-04 | 60 min |
| Season 16 | Episode 1 | Opening Day | 2014-09-11 | 60 min |
| Season 16 | Episode 2 | The Knockout | 2014-09-18 | 60 min |
| Season 16 | Episode 3 | Double Header | 2014-09-25 | 60 min |
| Season 16 | Episode 4 | The Lottery | 2014-10-02 | 60 min |
| Season 16 | Episode 5 | Sidelined | 2014-10-09 | 60 min |
| Season 16 | Episode 6 | The Tailgate | 2014-10-16 | 60 min |
| Season 16 | Episode 7 | The Drop | 2014-10-23 | 60 min |
| Season 16 | Episode 8 | Penalty Box | 2014-10-30 | 60 min |
| Season 16 | Episode 9 | Yes, Coach! | 2014-11-06 | 60 min |
| Season 16 | Episode 10 | Free Agents | 2014-11-13 | 60 min |
| Season 16 | Episode 11 | No 'I' in Team | 2014-11-20 | 60 min |
| Season 16 | Episode 12 | The Playoffs | 2014-12-11 | 60 min |
| Season 16 | Episode 13 | Kauai Part 1 | 2014-12-18 | 60 min |
| Season 16 | Episode 14 | Kauai Part 2 | 2015-01-01 | 60 min |
| Season 16 | Episode 15 | Makeover Week | 2015-01-08 | 60 min |
| Season 16 | Episode 16 | The Comeback | 2015-01-15 | 60 min |
| Season 16 | Episode 17 | End Zone | 2015-01-22 | 60 min |
| Season 16 | Episode 18 | Live Finale | 2015-01-29 | 60 min |
| Season 17 | Episode 1 | Money Hungry | 2016-01-04 | 120 min |
| Season 17 | Episode 2 | Taste Test / Keep On Truckin' | 2016-01-11 | 120 min |
| Season 17 | Episode 3 | Hooked On 'Tronics / The Big Switch | 2016-01-18 | 120 min |
| Season 17 | Episode 4 | Ready? Set. Auction!; Ship Shape | 2016-01-25 | 120 min |
| Season 17 | Episode 5 | Homeward Bound; Real World Problems | 2016-02-01 | 120 min |
| Season 17 | Episode 6 | Makeover Week | 2016-02-08 | 120 min |
| Season 17 | Episode 7 | I Got The Power/The Final Cut | 2016-02-15 | 120 min |
| Season 17 | Episode 8 | Live Finale | 2016-02-22 | 120 min |
| Season 18 | Episode 1 | Time For Change | 2020-01-28 | 60 min |
| Season 18 | Episode 2 | A Big Loss | 2020-02-04 | 60 min |
| Season 18 | Episode 3 | Supporting the Team | 2020-02-11 | 60 min |
| Season 18 | Episode 4 | Messages from Home | 2020-02-18 | 60 min |
| Season 18 | Episode 5 | Diving In | 2020-02-25 | 60 min |
| Season 18 | Episode 6 | Overcoming Obstacles | 2020-03-03 | 60 min |
| Season 18 | Episode 7 | Going Solo | 2020-03-10 | 60 min |
| Season 18 | Episode 8 | Boosting Morale | 2020-03-17 | 60 min |
| Season 18 | Episode 9 | Final Four | 2020-03-24 | 60 min |
| Season 18 | Episode 10 | Finale | 2020-03-31 | 60 min |
