While the twist is unprecedented for the show, the contestants, as always, are certain to grab viewers with their emotional stories. Among those undergoing lifetime transformations are Olympic gold-medal-winning wrestler Rulon Gardner, competing with his friend and business partner Justin Page. But here are a three more pairs to watch:
Courtney Crozier, 22, and Marci Crozier, 49
Daughter and Mother Team from Valparaiso, Ind.
When Courtney turned 21 last year, she just couldn't face celebrating it with her family. At 5'7" and 423 lbs., "I didn't like how I looked," she says. "I didn't like any of it. It was really hard." Though she tried out for past seasons of The Biggest Loser and didn't make the cut, Crozier took inspiration from the show and lost 100 lbs. on her own. Now she starts on season 111 at 323 lbs. while her mom joins her at 238 lbs. "I really came on the show because of Courtney," Marci says, "but once I got here, it stopped me on a dime. I thought, 'You need this.' "
Arthur Wornum, 34, and Jesse Wornum, 61
Son and Father Team from Portland, Ore.
At 5'8" and 507 lbs., Arthur Wornum, a married daycare provider with two kids of his own, is the season's largest contestant, and he wants to lose the equivalent of his father Jesse, who at 5'7" weighs 293 lbs. "Even at 646 lbs.," says Arthur of his heaviest, "I was still mobile. So I thanked God and asked him to give me the strength to make these changes. So here I am a year later and I'm down 150 lbs. but I still need to lose a whole obese person." Says dad Jesse, "I've been in an obese state since I was 25 years old. I've gone up and down, up and down. I stopped doing the diet thing. But I've never been able to put exercising and dieting together."
Dan Evans, 54, and Don Evans, 54
Brothers from Oklahoma City, Okla.
These twins are both 5'6" tall, live in Oklahoma City where they serve in local law enforcement (Dan as a police captain and Don as a lieutenant) and are married and have children. They both also want to lose weight – Dan is 287 lbs. and Don is 309 lbs. For Dan, motivation comes six years after his son, Adam, died. "Since his death, I gained almost all of [100 lbs. I previously lost] back," Dan says. "I have a daughter who has never known me as anything but this way, but I want her to be proud of me the same way Adam was." And Don's son Paul, 28, tried to get his dad to exercise but Don never committed. "He came to me a while back and said, 'I am not going to watch you die ... I don't want to see you any more and I don't want you to call me and I won't call you.' ... I know he loves me and this is his intervention on me. At about the same time, the show came up and I thought, 'This is a godsend.' "
Check back Wednesday (and every week) for Ada Wong's Biggest Loser blog on PEOPLE.com