At over 600 pounds, Kirsten undergoes weight-loss surgery.

At almost 700 pounds, Doug fights to overcome his food addiction.

At almost 700 pounds, Erica is desperate to undergo gastric bypass surgery.

Diana, at over 600 pounds, is a prisoner to her body.

Michael addresses his anger issues and undergoes weight loss surgery.

At over 700 pounds, Nicole risks leaving her two young children motherless.

At over 600 pounds and just 32 years old, Tanisha fears a premature death.

At almost 800 pounds, James is bedridden and can barely move his legs.

At over 600 pounds, most of Tracey's weight is in her misshapen legs.

Steven and Justin, brothers and nemeses, are pushed to lose weight.

Steven struggles to qualify for weight-loss surgery.

Lee and Rena make another attempt at weight loss to save their lives.

At over 600 pounds, Janine is immobile and pursues weight-loss surgery.

Alicia is afraid she'll die before she can marry or see her nieces grow up.

Liz attempts to reclaim her health and mobility with weight loss surgery.

At over 600 pounds and barely able to bathe herself, Karina makes a change.