Dr. Nowzaradan tells Tara that if she doesn't change her eating habits immediately, she'll only live five more years. Tara is reduced to tears when her mother delivers an ultimatum on top of that.

Chuck is surprised to discover that surgery didn't take away his cravings. He's still getting meals from the drive-thru.

Moving to Texas wasn't easy for Christina, but she's kept a brave face. Daunted by getting into her temporary home, though, she breaks down into tears.

Christina is shocked to discover how little weight she's lost after surgery. Her family offers her some excuses, but she tells them it's simply not good enough and she has to work harder.

Zsalynn is scared going into surgery, but she puts on a brave face for her daughter Hannah. She confesses that she wishes her husband were there to support her.

Zsalynn fights -- and wins -- the battle over tortilla chips at a Mexican restaurant, but she later falls prey to another food craving.

Paula mentally prepares for gastric bypass surgery by drastically altering her look with bright green hair dye.

James comes from a long line of family obesity and at 706lbs, is determined not to die in the same hospital bed that his father and sister did.

Penny is transported from her home in Maryland to see Dr. Nowzaradan in a Texas hospital. Once she's there, he shares some grim facts about her weight and BMI.

These individuals transform their bodies -- and their lives -- over an intense seven-year journey.

Olivia is placed in the hospital for 48 hours to assess her preparedness for gastric bypass surgery.

Olivia travels from Chicago to Texas to see Dr. Nowzaradan, but the 18-hour car trip is grueling for someone in her condition.

Post surgery Zsalynn enjoys the next step in her battle with obesity, but her victory is short lived with the arrival of her unsupportive husband.

Paula is motivated to work out with a personal trainer at her gym, but it's still going to take some time before Dr. Nowzaradan's diet advice really sinks in.

Chuck weighs almost 700lbs and it has hindered every aspect of his life. He's had to downsize his business and his wife feels like a single-parent, who is ready to leave him.

Christina's husband and mother are enabling her to eat 7,000 calories a day. She learns a tough lesson from Dr. Nowzaradan: When they put food in front of her, she must simply say no.

Chay reinvents himself as Lola and goes shopping for a new wardrobe.

Tracey describes the challenges growing up that led her to turn to food for comfort.

Steven describes the troubles he experienced as a child that led to his weight gain.

In an effort to lose weight, Marissa convinces her mother to go to the gym with her. Unfortunately, Jennifer feels she is unable to take such a big step at this time and they decide to take a walk around their neighborhood.

Steven demands fast food from his father as they make their way towards the hospital.

Will Ashley be able to turn her life around and achieve her goal of owning a childcare facility?

When "Who Do You Think You Are?" returns on Tuesday, Feb. 24 at 10/9c, celebrities will discover life-altering truths about their ancestors.

Lisa Kudrow visits The Talk to promote the newest season of "Who Do You Think You Are?" and announce that Talk host Julie Chen will appear on the show!

Get to know Dan Bucatinsky, Executive Producer of "Who Do You Think You Are?" In this video, the actor, author, dad and TV fanatic answers questions about his life and career.

Rachel and Kayleen McAdams explore the roots of their 5x great-grandfather who was actually a British loyalist in the American Revolution.

Rachel and Kayleen McAdams learn that their great ancestor James Gray was a British loyalist.

WHO DO YOU THINK YOU ARE? returns this spring to give eight new celebrities a unique opportunity to dig into their roots and learn more about their family history. New episodes begin Sunday, March 8 at 10/9c.

Minnie Driver unravels the deep family secrets her late father kept hidden.

Cynthia Nixon visits a prison to learn more about her ancestor, Martha, who was the only woman incarcerated there among dozens of men.

Rachel and Kayleen McAdams discover an English ancestor who lived and worked in a privileged world. As they unravel the mystery of their Canadian heritage, they uncover the harrowing circumstances that brought their family to Canada.

This season of Who Do You Think You Are? features J.K. Rowling, Alfre Woodard, Tom Bergeron, Ginnifer Goodwin, and Bryan Cranston.