After gaining back the weight she'd lost, Kirstie says she's struggled emotionally as well. "I've hated myself," she says. "You beat yourself up, and I [asked myself], 'What am I doing?'"

Though her first weight loss attempt wasn't entirely successful, Kirstie says one thing came out of it that's she's very proud of—she stopped smoking. "When I was on [your show] and fat, you said, 'You really have to stop smoking, because you can't be fat and smoke,'" Kirstie tells Oprah. "So I haven't smoked since. ... I think that this should be celebrated."