Jackie Warner Jackie Warner

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?

TVGuide.com: Which client surprised you the most?
Jackie Warner: Jeana really checked out and didn't want to change her lifestyle at all. It was interesting to me that someone would come into this program and try to maintain exactly what they were doing before and expect a different result. I was [also] surprised by Nikki, someone who came in with so much baggage, so much emotional work to do, and it was overwhelming for her because we were tackling not only the weight loss, but some serious emotional issues.

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TVGuide.com: Why do you think Stacy struggled so much?
Warner: It was very obvious to me who was working the program and who wasn't. I knew that Shay, Jeana, Nikki and Stacy were not following the program. Stacey's got PCOS (Polycystic Ovary Disease) which does make it more difficult to lose weight, but the calories I had given her were so greatly reduced from what she was normally doing that she should've been losing 4 or 5 pounds and she was only losing 2 a week. So even with the PCOS she could've done better if she had been following the program. Stacy was missing meals and then eating too much. We found out she was eating 1500 calories in shakes a day, in addition to her regular food.

TVGuide.com: Joe gave you heat for babying Nikki. Do you agree after watching?
Warner: I have to go where I think the most help needs to be. Joe wasn't so damaged in terms of his self esteem. In terms of Nikki, I had two choices: Either I release her from the program or I continue to show her I'm a presence and that I'm not going to let go of her. That's what I chose to do. Otherwise, I would've had to fire her from the program, and I don't think that would've been good for anybody. 

TVGuide.com: Why do you tell your clients to cut sugar first?
Sugar is an addiction — it releases the same chemical in the brain as heroin. I allow them to have sugar, but it has to be under 5 grams so you're not going to have an insulin spike. It doesn't alter the body or brain chemistry in that amount. I gave them other oral substitutes like tea at night, adding lemon juice to water to cleanse their liver, and the exercise further curbs the addiction. The problem with that is the exercise has to be consistent and they were only with me two times a week. The whole premise of the show is not me putting them in a house, restricting their calories, and watching their every move. It's me giving them tools for their real life. I can only interfere so much.

Check out photos from Thintervention

TVGuide.com: What's your go-to workout?
Warner: I lift weights. The more muscle you have on your frame, the faster your metabolism. Let's say I only have 15 or 20 minutes at the gym, I'm not going to jump on a cardio machine. I'm going to get a good circuit in, where I'm constantly moving, never resting, lifting weights. 

TVGuide.com: Is there any celeb you'd love to train?
Warner: Lindsay Lohan. I feel that I could maybe connect with her and retrain her addiction. She's clearly an addictive personality type and you can switch that addiction to healthy things.

TVGuide.com: What can you tease about the finale?
Warner: Some people lose weight and some people don't reach their goals. What I pitched initially about the show is that I don't want to do just a weight loss show — I want to do a life change show. I want the viewers to see the connection and actually change the pattern in their life that will give them long-term success. In terms of that, everybody succeeded greatly.