Twins David and Rebecca didn't think that much about their weight as they were growing up in North Prairie, WI. Dave, who weighs in at 470 pounds, and Becca, who weighs 398 pounds, spent their childhood making people laugh. Behind the smiles there were tears of pain from a difficult upbringing that led them to use food as an outlet. This brother and sister duo need help getting control of their weight. Well, help is on the way!
Chris Powell surprises the twins on their 23rd birthday. He realizes they're extremely co-dependent and enable each other's poor decisions, especially when it comes to their weight. After a rough first workout and a tearful goodbye, the twins are split up for a 90-day challenge, with Becca going to Arizona to work alongside Chris's wife, Heidi. At the beginning of his weight loss journey, Dave says he'd always wanted to go through Navy SEAL training to show his dad that "he was a man." The twins have Phase 1 goal to lose 200 pounds between them.
Dave comes home to a completely redone workout room. It’s a much more inspiring place. Chris surprises him with a visit at the 45-day mark. He’s happy to hear that he’s getting support from his dad. However, he still can’t talk to him about his past issues with drugs and suicide. In Arizona, Becca is introduced to Chris’ wife, Heidi and her exercise therapist, Richard. She also meets former weight loss participant Jacqui. Becca hits the track for a rough workout. Her knees take a major beating, but Becca presses on. She takes on bleacher steps, track runs and MMA training.
At the 90-day weigh-in, Dave and Becca are reunited. Both are amazed how much weight each of them has lost. David takes to the scale first. He’s lost 112 pounds and is down to 358. Becca started at 398. She needs to lose 88 pounds to meet the combined weight loss goal of 200 pounds. Becca lost 92 total pounds which means they lost 204 combined. For the next phase, Becca must lose 57 pounds while David is tasked with dropping 75.
Dave and Becca are together again. The struggle is working with someone who doesn’t follow the same routine as the other. This concerns Chris, who doesn’t see Dave pushing himself like he was before. At the six-month weigh-in, Becca comes in at 248 pounds. She beat her goal by one pound. As for Dave, he came up 13 pounds short of his goal, but he’s now under 300. Chris lets them know that their milestone is taking place right away. They are embarking on some legitimate Navy SEAL training.
Chris turns Dave and Becca over to the SEAL team trainers. The twins are challenged to a rigorous "Kokoro" training camp designed to forge mental toughness and modeled on Navy SEAL Hell Week. Becca struggles mightily during the beach run. She’s terrified when she’s told to link arms with the others while lying in the ocean. Her coach pushes her to run back to the gym. Becca collapses before they get there. She works through a panic attack to get back up. Dave is happy to have her back. Becca takes charge of the rest of the grueling workout. This inspires her brother to continue.
Dave and Becca must lose a combined 76 pounds for Phase 3. Trouble arises. Dave doesn’t want to always exercise and Becca takes cues from him to possibly binge. The two of them argue about this issue. Becca feels like she’s being sabotaged by her brother. At the 9-month weigh-in, Chris notices the confidence in his clients. He also learns that they are struggling with their relationship with each other.
At the weigh-in, Dave is shown to have lost only 28 pounds. As for Becca, she’s dropped 20 pounds. They didn’t meet the goal, but they have chopped a significant chunk of their body fat. Dave is a good candidate for the skin removal surgery, but his sister is not. This has him feeling guilty about how he treated Becca over the past three months. For the final phase, the twins are separated once more. Dave begins his journey by telling his dad about his suicide attempt by drugs. He says that a phone call from his father where he said that he loved him was all he needed to turn things around. His dad saved his life.
The time comes for the final weigh-in. Dave steps out to the cheers of an amazed crowd. He gives his dad a hug before taking the stage. Dave hasn’t seen his sister in three months. He’s blown away by how great she looks when she joins him on the stage. Tears flow. Dave steps onto the scale to see his new weight of 258 pounds! He lost a total of 212 pounds over the course of a year. Becca is up next. She weighs in at 192 pounds. She lost 206 pounds! She’s now a candidate for the skin removal surgery. Combined, Dave and Becca lost a total of 418 pounds! They are a new generation wonder twins!