LOS ANGELES, Sept 16 (Reuters) Health and fitness guru Bob Harper shot to fame as a trainer on “The Biggest Loser” reality TV series, which begins its 12th season on Tuesday on NBC, after becoming an improbable hit for its network.The show has obese people compete in various fitness contests over a period of time to see who loses the most weight, and in the process both the contestants and audiences learn about health, nutrition and themselves.At a recent event for health care company Anthem Blue Cross, for which Harper is a spokesman, the 46-year-old trainer sat down with Reuters to talk about the upcoming season, why he stopped being vegan and his obsession with his best friend.Q: First, the burning question: how is tennis star Anna Kournikova doing as the new replacement for Jillian Michaels, the longtime trainer who elected not to come back this season?A: “It’s been an adjustment. I would love to say that everything is perfect. Jillian is one of my dearest friends. I’ve been working with her since the beginning (of the show). Anna is bringing in her own style, her own technique from her years of being a tennis player and competitive athlete.”Q: What can Anna offer contestants trying to lose weight?A: “There’s a certain amount of competition that she brings. But it’s going to be the audience’s decision, won’t it? You can never fill Jillian Michael’s shoes. She’s one in a million. Anna came in not wanting to be Jillian at all. That’s what she has going for her.”Q: Are there any contestants this year that are particularly inspiring to you?A: “Antone Davis. He’s an ex-football player and his life went dangerously wrong with his health. He stopped playing sports and got up to 450 lbs. People are always inspired by athletes that have gone awry and then come back, so I think that people are really going to love him.”Q: The contestants go through a lot physically and emotionally to lose weight. How safe are the show’s methods?A: “We all know the rule: you should be losing one to two pounds a week on a proper weight loss. But we are doing a reality show that is an extreme reality show that also brings with it hope and inspiration. So when you can stop comparing yourself to the weight loss you see on our show and get inspired to get off the sofa and make a change, then we’re doing something right. But our contestants are all under medical supervision.”Q: You recently stopped being a vegan. Why?A: “I still believe that a plant-based diet has tremendous health benefits but I have incorporated more animal protein into my diet. I found that my body personally got to a point where I needed something more. I used to yell at people who said that, but now all of a sudden, my body just kind of went, ‘I need something.”‘Q: Is there a common mistake you see people make when trying to lose weight that frustrates you?A: “When people work out hard, but not smart. I see people trying to go as hard as they can at the gym because they made poor choices of eating the night before and they’re thinking, ‘I gotta pay because I played.”‘Q: What’s the better solution?A: “If they can rein their diet in a little bit more, focus on a healthy lifestyle, then it can be a lot easier. Our bodies want to be healthy. I see that on my show all the time with people who are morbidly obese. When they start to make changes, their numbers start changing.”Q: How has the show changed you?A: “I’ve lived in Los Angeles for over 20 years. I was the fitness guy that was the celebrity trainer working out people that (were already skinny).“All of a sudden I went to this morbidly obese world and it really awakened something in me. It was like, ‘Oh this is what I’m supposed to be doing.’ It awakened a calling in me and I love it. I’ve been given a really big platform to reach as many people as I can. And I take that very seriously.”