Transcript for Oprah Announces She's Lost 40 Pounds
She is on a personal journey to live her best life and this morning Oprah has reached a major milestone and ABC's Mara schiavocampo is here with all of the exclusive details. Mara, this was embargoed. Because we're hearing for the first time what she has done over the last year. Like so many of us, Oprah made a weight loss resolution last year and now we're learning that she's made good big time. Revealing in a new weight watchers ad campaign just how much she's lost. Crediting her success to an entire lifestyle shift. This morning, Oprah is revealing she's accomplished one of her goals since setting this 2016 resolution last December. I don't have like a dress or some big red carpet thing. I have to do -- I'm just looking at 2016 as the year of my best body. Reporter: The 62-year-old announcing a huge milestone in her weight loss journey. Since I started weight watchers I've lost over 40 pounds. I can honestly tell you I struggle no more. Reporter: Through the years Oprah's shared her struggles with weight. It's not about the food. It's no using food. Reporter: Now the media mogul is getting results from the beyond the scale program and encouraging others to live fully with the help of the company she owns a portion of calling weight watchers a lifestyle, a way of eating and a way of living that is so freeing. I live well while losing weight. It is easier than it's ever been. Reporter: Weight watchers new campaign encouraging people to live the life they want. I've eaten everything I love, taco, pasta, I've never felt deprived. Reporter: And, of course, one of Oprah's favorite things, bread a food she spoke about back in January. I don't deny myself bread. I eat it every day. Reporter: Telling "Gma" the program is one of the things helping her live her best life. How is weight watchers? You've got your hands in a lot of different projects. So I'm at a point in my life where I actually for years in the magazine "O" magazine talked about balance and living your best life, I actually am doing it. Reporter: And weight watchers said with their new programs mens are now losing 15% more weight than before and Oprah, of course, is not just a happy customer she also owns 10% of weight watchers and she says another really big key for her having a weight loss partner her diet buddy is Stedman and I'm a big fan of having a buddy. You got to do it with someone. It helps and feel like you're in it with someone else. Look who we have here now our senior medical contribute Dr. Jen Ashton. Thanks for being with us. Good morning, you guys. Important to know you are board certified in obesity medicine. Talk about the significance of Oprah's weight loss. Let's do simple math. In the world of obesity medicine the gold standard is the loss of just 5% to 10% of your starting body weight so while people who are overweight and obese want to lose a lot more than that, just 5% has been shown to do some dramatic positive things internally for meth benefits. Talk about 40 pounds unless you started at 800 pounds that is significant weight loss. And she's Ken the weight off a little more than a year. But what is the likelihood that Oprah or anyone else can keep it off for good. You say likelihood. In the world of medicine and nutrition when you talk about statistics to be clear, we do that because that's what data gives us but for you you're not going to be 84% successful. It's going to be all or none so you have to take that with a grain of salt. Good news/bad news here. The good news is that weight loss experiences definitely vary individual to individual and everyone will have their own journey on that. There's also really good data that your initial weight loss predicts long-term success did you 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 and it's not a matter of willpower. She's made a lifestyle change. She no longer struggles and worries about it like she did. I think she looks the best she's ever looked. Your mind will follow and your body -- you need that equilibrium. Power of positivity and Stedman apparently.
This transcript has been automatically generated and may not be 100% accurate.