Marie Osmond foxtrotted off the pounds on national TV.
Pounds lost: 45
How she did it: NutriSystem and Dancing With the Stars

Marie Osmond had always felt her body was a ticking time bomb. Her mother, father, and grandmother had passed away from heart disease, and she wanted to be around for her five kids. So when her son asked her to lose the weight, it was an easy decision. "It was very touching to me. The fact that I am a single parent made me reevaluate," she says. Although Marie lost weight fairly quickly while competing on Dancing With The Stars, she had also coupled her physical efforts with the NutriSystem program, which slimmed her down from a size 10/12 to a 2/4. And she's happier than ever. "The weight loss is not why I am happy," she explains. "I made a lot of serious decisions in my life before I lost the weight. I think it is important to be at peace in your life."

After struggling with her weight for a lifetime, Carnie Wilson went under the knife.
Pounds lost: 92
How she did it: Gastric bypass

In 1999, at 300 pounds, Carnie Wilson had gastric bypass surgery and lost a whopping 50% of her weight...150 pounds. Although Carnie was ecstatic with the results, they didn't last. After she gave birth to her daughter, Lola, she had trouble dropping the baby weight. That inspired Carnie to go on VH1's Celebrity Fit Club, where she lost 22 pounds. Today, Carnie is back at 208 pounds, wearing a size 16, and admits she has "hit rock bottom with her weight." Carnie attributes her weight gain to the demands of motherhood--leaving her no time to focus on her diet. But Carnie is optimistic she'll lose the weight. "I'd like to lose 45 to 50 pounds and then try to get pregnant again," she says. "I know I will do it! I don't consider myself a failure. I just got off track." If she did it before, she can do it again!

She was always cast as the "fat girl"... but Ricki Lake reinvented herself and her body.
Pounds lost: 137
How she did it: Diet and exercise

When Ricki Lake, 38, weighed 260 pounds and wore a size 24, she wasn't happy. For 20 years, the former talk show host had tried every crash diet around, frequently fainting because she wasn't eating enough. When she finally decided to lose the weight, she signed up for "Fresh Dining," a delivery service that offers calorie-controlled balanced meals. Now 123 pounds and a size 4/6, Ricki reveals the happy side effects of weight loss: "For the longest time, when I was very heavy, I couldn't cross my legs. I couldn't physically do it. Love that I can cross my legs now...even my shoe size is changing. My Jimmy Choo's are too big now." Go, Ricki!

Valerie Bertinelli became the face of Jenny Craig...and dropped major weight.
Pounds lost: 40
How she did it: Jenny Craig

Valerie Bertinelli, 47, began hating her body at an early age. She was always "America's Sweetheart," but she surprisingly fell from grace when she entered into a turbulent relationship with a rock star and spiraled into drugs and alcohol, which took a major toll on her body. At age 40 and 172 pounds, she decided to get her life under control with the help of Jenny Craig. The plan helped her learn portion control, and to rely more on how she felt and looked as an indicator of success, rather than what the scale said. She stopped emotionally eating once she realized she was snacking out of boredom. And then she began to keep pre-made foods like hardboiled eggs or chopped veggies handy. She also bought an elliptical machine and starting walking with a pedometer. Valerie soon lost 40 pounds on the program, whittling down to 132 pounds and became the spokesperson for the company. The best lesson she learned? Forgiveness. Now, if she lets her diet slip, she just starts up again, guilt-free!

The Biggest Loser host Alison Sweeney has experience losing weight herself.
Pounds lost: 30
How she did it: Cutting out sweets

Days of Our Lives' star Alison Sweeney, 30, admits the pressure to be thin in Hollywood has affected her, and she spent years on fad diets to stay slim for the camera. At one point, she even considered taking "eating worms"--tapeworms that settle in the stomach to prevent weight again. Thankfully, she never went that far, but the actress often binged on sugar, which destroyed her teeth and metabolism. Her dentist advised her to go off sweets (no soda, carbs, not even artificial sweeteners) and, as a result, Alison lost 30 pounds and dropped to a size 4 in just three months! Her new diet consists of foods like turkey bacon, salad with tuna, and limited carbs. This mother of one, with one on the way, keeps the weight off by staying busy on the set knitting and chugging water.