Kelly Osbourne admitted Thursday in a podcast interview that her recent, dramatic weight loss is partly due to undergoing gastric sleeve surgery. “I did the gastric sleeve. All it does is change the shape of your stomach,” the 35-year-old Osbourne explained. “I got that almost two years ago. I will never, ever, ever lie about it ever. It is the best thing I have ever done." She also said the decision to go under the knife came after two years of Osbourne deciding if she still wanted to be in showbiz and "figuring out if I was even capable of even losing this weight." While Kelly says mom Sharon was her biggest weight-loss "cheerleader,"ET notes that Sharon has spoken out about how much she regretted her decision to undergo gastric bypass surgery in 1999. "I felt [like] such a cheat when I had that band on my stomach," Sharon told ET back in 2014. "People are saying, 'You look wonderful!' I'd go, 'Thank you, I just have to leave and vomit.'" Sharon ultimately had her band removed in 2006.