She's known for her tough love on The Biggest Loser, but fitness expert Jillian Michaels tells Rachael that she has the best intentions when it comes to her no-nonsense attitude toward the contestants. "They come to the campus," she says, "and they really have no concept of how strong they are or what they're capable of, and on certain occasions I have to intimidate them into healthy behaviors. But once they realize that they can do it, then they'll hopefully take off from there."

Jillian can empathize with the contestants, having struggled herself with weight issues as a child and then a teenager. "My mother, God bless her, had the foresight to get me into martial arts," she says. "Not because I was a fat kid, but more because I was troubled, going through hard times and struggling with many different things, and she thought that it would be a great outlet for me. And that's really where I developed my philosophy about fitness, not only as a means to get healthy, but as a way to change your life. Your health is the platform your entire life sits on top of, and when your health is good and you feel strong, it transcends into every facet of your life."

As the holiday season kicks into high gear, the temptation of delicious foods is unavoidable, so Jillian shares her tips for staying fit and healthy during the holidays:

• Revamp your meals. "White meat, not dark meat. Have salad and steamed vegetables instead of fattening casseroles. Go with baked sweet potatoes instead of candied yams. Fruit salad instead of fruit pie, and whole grain roles instead of biscuits."

• Communicate with your family. "So many people have a lot of stress if they're on a diet or trying to stay healthy," Jillian says. "There's food pushing going on, or grandparents who want to be validated and that's how they show you love. Tell them what you need, and how to support you -- say, 'Grandma, I would love it if you could come up with a low-calorie cheesecake recipe for me.'"

• Stay in control. If you're trying to watch what you eat, bring your own dishes when going to a party, or eat a healthy meal beforehand so you don't arrive hungry and are susceptible to temptation.

• Get minty fresh! Chew on gum to avoid grazing while cooking -- it makes it less conducive to overeating. And brush your teeth when you're done eating so you don't go back for seconds.

Squeeze in fitness whenever possible. If you're traveling during the holidays, try to stay at a hotel that has a gym, or bring workout tapes with you.