The Biggest Loser is an American competition reality show that initially ran on NBC for 17 seasons from 2004 to 2016 before moving to USA Network in 2020.

The trainers are responsible (in conjunction with medical personnel retained by the show) for designing comprehensive workout and nutrition plans and teaching them to the contestants.

Some episodes have been aired in a shortened one-hour format to accommodate adjacent network programming such as The Voice[4] and the State of the Union address.

"Simply put, the Biggest Loser provides viewers with a completely inaccurate picture of what you must do to lose weight and live healthy.

Consult with your own doctor before embarking on any diet or exercise program.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".

[11] The weight-loss regimen used in the show—severe caloric restriction combined with up to six hours a day of strenuous exercise—involves risks including a weakening of the heart muscle, irregular heartbeat and dangerous reductions in potassium and electrolytes.

[6] The Biggest Loser: Second Chances 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).

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".

[6] 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.

[15] 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 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...

The article quoted Dr. Michael Rosenbaum who said, "The difficulty in keeping weight off reflects biology, not a pathological lack of willpower."

[18] Recent seasons have been filmed at King Gillette Ranch on Mulholland Highway near Malibu Creek State Park.