The fourth season premiered on September 11, 2007, with 18 overweight contestants in a weight loss competition for an ultimate prize of $250,000.
Instead, they remained in the desert and trained in secret with their trainer, Jillian, until they arrived on campus for the weigh-in at the end of week 2.
Only Amy, who felt betrayed by Kim's negative comments prior to the previous week's elimination, opted to change trainers, choosing to train with Jillian.
That same week, Neil, a contestant on the original blue team, ignited controversy when he threw the weigh-in by water loading, which resulted in a weight gain of 17 pounds.
The trio with the lowest combined percentage of weight loss is considered to have fallen below the yellow line, and its members are up for elimination.
The pairs were: Kae and Amy; Hollie and Bryan; Nicole and Neil; Isabeau and Ryan; Bill and Julie.
Bold denotes who has the overall highest percentage of weight loss as of that week 18 contestants race through the desert.
After not being picked, Julie, Jim, Jez, Isabeau, Hollie and Bill are met by Jillian, who informs them they are not going home, but forming the Black team, and will train in secret for two weeks before rejoining the competition on the ranch.
Lezlye reveals that she has lost 55 pounds since she first arrived and now has let Hurricane Katrina go and moved into a new house with her son.
The Red team wins the weigh in behind Phil's 9 pound loss during a week with a lot of low numbers.
Jerry is revealed to have lost 88 pounds since starting the show and encourages other seniors to make a change as well.
This week, the trainers face a temptation - they must eat cupcakes to win their team a 15-second advantage in the upcoming challenge.
Isabeau, Hollie and Julie work to persuade Jez to team up with the girls and send one of Jim or Bill home.
Kae, Hollie and David win the weigh-in and Bill is the Biggest Loser, with a percentage weight loss of 2.61%.
Neil initially denies gameplay, but eventually admits he threw the weigh in to force the elimination of a former Black team member.
The challenge tests the players' endurance by seating them on a platform over water and having them hold up their own weight by a rope.
Neil is this week's Biggest Loser with a percentage weight loss of 5.31%, and becomes the 5th contestant in the history of the show to lose 100+ pounds on the ranch.
Additionally, Hollie gains the power to give another player a 24-hour trip home and immunity and chooses Julie.
If either Hollie or Julie gain weight, their immunity is void and they can fall below the yellow line.
Hollie and Julie return from their visit home in time for the weigh-in and both women lost zero pounds.
The contestants are in for a surprise and arrive at the NBC studios and are escorted to the Days of Our Lives set while Allison is rehearsing with some of her co-stars.
The players receive ultimate makeovers, are surprised with visits from family members and take part in a photoshoot for Prevention magazine.
After the flair, the contestants head to this week's challenge, which requires them to keep themselves above a literal yellow line by climbing up ropes.
Kim tries to isolate where Bryan's nutrition is taking a hit and found out he was marinating meat in soy sauce.
Neil has shed a ton of fat, Julie has lost about 12 inches from her waist and Isabeau is no longer pre-diabetic and has the lowest insulin level of the remaining players.
Bob teaches time-saving food portioning while Jillian preaches high-intensity training to burn more calories in a shorter amount of time.
The players go to work at a pizzeria washing dishes, cleaning bathrooms, taking out trash, and prepping and serving food.
At the weigh-in, despite excellent numbers, Neil, despite losing ten pounds, and Hollie fall below the yellow line.
The remaining players vote to eliminate Neil, meaning that for the first time in Biggest Loser history, the finals will consist of contestants from one team (Black).
Those confirmed to appear in the episode include: Finalists Bill and Julie, and eliminated contestants Jim, David, Nicole, and Neil.