The Biggest Loser is an American competition reality show that initially ran on NBC for 17 seasons from 2004 to 2016, returning in 2020for an 18th and final seasonon USA Network. The show features obese and overweight contestants competing to win a cash prize by losing the highest percentage of weight relative to their initial weight.
Each season of The Biggest Loser begins with a weigh-in to determine the contestants' starting weights, which serve as the baseline for determining the overall winner at the end of the 30-week competition.
Contestants are grouped into teams of three, with each team assigned its own t-shirt color. Contestants work with trainers, who (in conjunction with medical personnel retained by the show) are responsible for designing comprehensive workout and nutrition plans and teaching them to the contestants, who are individually responsible for implementing the principles taught. Depending on the season, a team may work with a specific trainer, or all trainers may work with all contestants.
During an episode, various challenges and temptations (see below) are featured. Winning a challenge affords special advantages, such as a weight advantage for the next weigh-in or full immunity from being voted off the show.
Each week culminates in a weigh-in to determine which team has lost the most weight for that week, using contestantsâ percentages of total weight lost. The team with the lowest percentage lost during that week (known as âÂÂfalling below the yellow lineâÂÂ, which refers to a line featured on a video screen showing the cutoff between safety and being at risk) will have one member voted off, unless the team consists of only one remaining member, in which case there is no vote. The vote is usually cast by the other teams, though some episodes feature one team making the decision alone. Some episodes feature a second, "red line"; if a contestant falls below the red line, the contestant is automatically eliminated with no vote. Other episodes allow the contestants to all receive immunity for the week if they successfully meet a goal at the weigh-in.
When the number of contestants has shrunk to a predetermined, smaller number (unknown to the contestants), the teams are dissolved and the contestants compete against each other individually.
The season finale reunites the final contestants remaining on the show with those eliminated. The eliminated contestants compete for a smaller prize while those remaining on the show compete for a larger prize and the title of "The Biggest Loser".
Episodes are typically two hours long. Some episodes have been aired in a shortened one-hour format to accommodate adjacent network programming such as The Voice and the State of the Union address. Each episode features some, but not all, of the following activities (some contestants may not participate in an activity with physical requirements if placed on medical restrictions):
According to LiveScience.com, "physicians and nutritionists worry the show's focus on competitive weight loss is, at best, counterproductive and, at worst, dangerous". Contestants on the show lose upwards of 10 pounds per week (in the very first week, some contestants have lost 20âÂÂ30+ pounds in that one week alone), whereas the established medical guidelines for safe weight loss are between 1 and 2 pounds per week.
Other health writers take it even further, suggesting that everything from the show's dietary guidelines to workout routines are completely flawed.
Nutritionist Dr. Barry Sears sums up the wellness paradox: "First, eating less can cause stress to the system causing more hunger. Second, the more people exercise, the hungrier they become." Dr. Sears continues by claiming that "even with the most intense training, people are unlikely to add more than five pounds of muscle in 12 weeks of weight training. The reason viewers see their muscles emerging as the show goes on is because as the layer of fat surrounding the muscles is lost, muscles become more visible. Those muscles were always there but covered by a mass of fat tissue.
At the end of every telecast, the following disclaimer is shown:
Despite this claim of supervision, however, all contestants are required to sign a waiver that states: "no warranty, representation or guarantee has been made as to the qualifications or credentials of the medical professionals who examine me or perform any procedures on me in connection with my participation in the series, or their ability to diagnose medical conditions that may affect my fitness to participate in the series".
The weight-loss regimen used in the showâÂÂsevere caloric restriction combined with up to six hours a day of strenuous exerciseâÂÂinvolves risks including a weakening of the heart muscle, irregular heartbeat and dangerous reductions in potassium and electrolytes. Contestants, regardless of their weight, are required to certify that they believe they are "in excellent physical, emotional, psychological and mental health".
' included a one-mile foot race in its first week, an event that led to the hospitalization of two of its contestants; Rob Huizenga, the show's medical consultant, when asked about the foot race said that "If we had it to do over, we wouldn't [have done] it" and noted that in response, the show's producers have "changed a lot of the way [they] do things" (including the close monitoring of contestants' body temperatures during exercise).
One attempt to create a healthier environment after Season 8's dangerous foot race was to include a pool for low-impact cardio. This helped contestants to lose weight more healthily and safely than some previous exercise routines in earlier seasons.
Because the show involves elimination, some contestants are encouraged to take risks that endanger their health to remain in the competition. Ryan C. Benson, the winner of the program's first season, publicly admitted that "he dropped some of the weight by fasting and dehydrating himself to the point that he was urinating blood". Since the show, Benson has regained all of his weight but 10âÂÂ12 lbs. In 2009, Kai Hibbard (runner-up from the third season) told The New York Times that "she and other contestants would drink as little water as possible in the 24 hours before a weigh-in" and would "work out in as much clothing as possible" when the cameras were off. She further stated that two weeks after the show ended, she had regained about 31 pounds, mostly from staying hydrated. In a June 2010 interview, Hibbard said, "I do still struggle [with disordered eating]. I do. My husband says I'm still afraid of food... I'm still pretty messed up from the show."
According to a report by The New York Post, California authorities inquired the show due to allegations of doping contestants. The show dismissed these allegations as false and without merit. The show is under internal investigation as of July 2018.
Further allegations were detailed in a 2025 Netflix documentary series, '.
In 2016, the results of a long-term study by the US National Institute of Health (NIH) were released that documented the weight gain and loss of contestants in Season 8, which aired in 2009. The study found that most of the 16 contestants regained their weight, and in some case gained more than before they entered the contest. Their metabolisms had slowed to the point where they were burning hundreds of calories a day less than other people of their new, reduced size. The New York Times reported: "What shocked the researchers was what happened next: As the years went by and the numbers on the scale climbed, the contestants' metabolisms did not recover... It was as if their bodies were intensifying their effort to pull the contestants back to their original weight." The article quoted Dr. Michael Rosenbaum, who said, "The difficulty in keeping weight off reflects biology, not a pathological lack of willpower."
After the study results were revealed, former contestants demanded that NBC cancel the show.
Seasons two and three of The Biggest Loser were filmed at the Hummingbird Nest Ranch. The ranch is an equestrian estate in Simi Valley, California, northwest of Los Angeles. Recent seasons have been filmed at King Gillette Ranch on Mulholland Highway near Malibu Creek State Park.
Given to the person losing the most percentage of body weight under the eliminated contestants.
The following table contains records for the American version of The Biggest Loser. Only records that were officially announced on the show are included.