Jackie Warner's clients know what they're getting into when they sign up to be her trainees. But for some of the cast of Bravo's Thintervention with Jackie Warner, the lifestyle changes weren't so easy. The no-nonsense trainer (her best-selling book is titled This is Why You're Fat) says she was most surprised by Real Housewife of Orange County's Jeana Keough, who came into the program not wanting to change her routine, yet saw results. Warner tells TVGuide.com why Jeana, Shay and Stacy struggled to lose weight, and what to expect from the show's finale. Plus: Which celeb would Warner love to work with?