NBC has aired 15 seasons full of success stories on The Biggest Loser since 2004, but once the cameras stopped rolling, where those stories still successful?
A new installment of "Oprah: Where Are They Now?" follows up with some of the reality stars to see how their lives have changed since the experience ...
One star who definitely kept it off? Julie Hadden. And not with the help of Jillian Michaels cheating. Just kidding. Sorry. Low blow. Anyway, back to Julie.
On The Biggest Loser Season 4, she came in second place by dropping 97 pounds. In the years since then, Julie went on to battle infertility issues.
She finally got pregnant at age 40, and is now happy stay-at-home mother of three, as well as an author and public speaker who inspires others.
In Season 2, Matt Hoover took home The Biggest Loser title after dropping 157 pounds. He fell in love with co-star Suzy Preston, who lost 95 pounds.
The couple married less than a year later, and they remain married today. Oprah first caught up with Suzy after she gave birth to their second child.
"I hadn't eaten anything good in two years," she said. "Once the doctor said, 'You really shouldn't be on such a restrictive diet,' I said, 'Okay. No problem.'"
Today, Matt and Suzy say they no longer live by a number on a scale. They've regained some of the weight, but keep active with their two boys.
Season 5's Mark Kruger, a father of two who originally weighed 285, says he's been able to maintain the nearly 100 pounds he lost on the show.
He tells Oprah he's doing better than ever these days by avoiding the pitfalls of processed foods and by working out six days out of every week.
How are the rest of the cast members from The Biggest Loser doing? We'll find out when Oprah: Where Are They Now? airs Sunday at 10 p.m.