Oprah Winfrey Announces She Lost 40 Pounds

— -- Media mogul Oprah Winfrey announced today that she reached the milestone of losing more than 40 pounds, crediting the dramatic slim-down to her "lifestyle" on Weight Watchers.

“I can honestly tell you, I struggle no more,” Winfrey, 62, said in a new ad. "I’m eating everything I love — tacos, pasta. I’ve never felt deprived."

Winfrey bought a 10 percent stake in Weight Watchers last year and joined its board. She also began fronting its ads, including the latest, the "Live Fully" campaign, which is set to debut after Christmas and aims to help people live life to the fullest by focusing on maintaining good health.

"Weight Watchers is easier than any other program I’ve ever been on. It’s a lifestyle, a way of eating and a way of living that’s so freeing. You never feel like you are on a diet and it works," Winfrey said. "I believe others who are looking to make a change will be as inspired as I am about the stories we are sharing in this new campaign."

Winfrey has kept the weight off for a little more than a year, but data finds that many struggle to keep the weight off for good.

“The good news is that weight-loss experiences definitely vary individual to individual and everyone will have their own journey on that,” Dr. Jen Ashton, ABC News' chief women's health correspondent, said today on “Good Morning America.” “There’s also really good data that your initial weight loss predicts long-term success. The bad news: data clearly tells us that at the two year mark most people are back up at where they started. That doesn’t mean it’s impossible, it just means it’s very difficult.”

Winfrey, 62, is endorsing the campaign in two new television ads, sharing her personal weight-loss success story and how the program has helped her live a "fantastic and full life."

Winfrey's weight has long been a topic of conversation. In 1988, Oprah revealed her new 145-pound figure and wheeled out a wagon filled with 67 pounds of fat to represent the weight she'd lost.

In 2008, she tackled her 40-pound weight gain on the cover of O, the Oprah Magazine by superimposing a bigger photo of herself next to a photo of her in a crop top.