Jillian Michaels knows better than anyone what it’s like to be a fat kid. Hard to believe, maybe, looking at her rock hard, 115-pound, 5’2 and a half-inch physique. But it’s true–as a teenager, Michaels, now 37, once weighed in at 175 pounds. She credits martial arts with helping her slim down–and a drill sergeant teacher with inspiring (read: terrifying) her to Get Serious.

“I was being more active but I was still eating like s*** and my martial arts instructor gave me an ultimatum where he was like ‘Take this seriously or get out. I don’t have the time for this. Don’t insult me, don’t insult what I do,’” says Michaels, who, in her cut-off shorts and gray Havaianas flip-flops, her chestnut-colored hair tied back in a loose bun, looks about 16. “For a while I was pissed and what have you, and then I was like, ‘I need this in my life.’ I went back and cleaned up my act.”

She’s also put her past experiences to good use. For the past eight seasons Michaels has been the drill sergeant cum trainer on the Biggest Loser, barking orders at hapless contestants and whipping them into shape. While her in-your-face style offends some folks, she is admired for her honesty, and for so obviously caring about the people she encounters. (Millions of viewers can’t be wrong, right?)

Now she’s got her own show, Losing It, in which she moves in—yes, you read that right—with families across the country, and helps them with their issues..all of ‘em, and not just the ones related to the numbers on the scale.

“The idea about weight on the show is that when you are unhappy you’re going to be unhealthy in every facet of your reality–so you’re going to be overweight, you’re going to have problems in your family relationships and dynamics, you’re probably suffering with regards to your career,” says Michaels.

She knows of what she speaks—her own life has been anything but smooth. She grew up in Los Angeles and her parents divorced when she was about 12. The divorce was so traumatic that she ate her way through it. At 17, her mother threw her out of the house, and Jillian fended for herself. She ended up taking classes at California State University Northridge. She left after a year, became a literary agent at ICM, got herself certified in fitness. She was the owner of a sports medicine facility when she was asked to audition for “The Biggest Loser”.

Michaels thinks a large part of her appeal is her honesty.  “I’m not compassionate. I’m not sympathetic. I’m empathetic,” she says, her blue-green eyes shining. “When you’re sympathetic it’s almost like agreeing with someone’s idea of who they are: ‘Oh, poor baby you’re weak and pathetic.’ But empathetic is like, ‘Yeah, it’s hard, yeah, it sucks. Now do the work and let’s fix it. Because I’ve been there and I’ve done it…don’t give me your pity party.’”

How did you find the families for Losing It?

We put out a giant casting call. We went to families that we thought America would love and relate to. Single mothers, families that have lost their jobs, that have lost loved ones, families that have been hit by cancer and overcome it. You name it—we’re trying to get at those issues that Americans are dealing with.

Did you have a say in the casting?

Yes. I was able to watch the casting tapes and I was really nervous because the people are Biggest Loser heavy. And they work full time jobs. And I have two months. Biggest Loser is eight to ten months.  And I was like, ‘Oh my god, when we come back in two months it’s like, ‘Congratulations you’ve lost 30 pounds.’ You know what I mean? They’re not going to look different. It’s not a weight loss show, but if we cast them that heavy I’m afraid people will think that. But you know what– we cast the families that we thought that needed the most help and I’m just hoping America is like ‘Ok, I get it, they’re on track. Their life is back on course.’

Well, most people can’t take eight to ten months off to lose weight. This is reality.

This is reality. My only hope is that I wish we could come back in 6 months. Start to finish, the episode is eight weeks, sometimes six. …. In a perfect world I would have 6 months.

Do you think your style is effective in helping people lose weight?

Absolutely. Don’t the results speak for themselves?  I mean, I’ve taken thousands of pounds off people on television. It is what it is.

Jillian Michaels, once an overweight teen.

You’ve said that your martial arts teacher terrified you. Is he still alive?

Oh, yeah.

You’ve gotta go back and see him.

Oh no! He’ll beat the s*** out of me.

It would be great TV: ‘Meet the person who’s Jillian Michaels’s  worst nightmare!’

He’s extreme. You think I’m extreme? America wouldn’t understand. I used to have to set rat traps off of my fingertips and stuff. He’s bananas. People would not get it.

Being fat as a kid: did that shape your life?

Oh, yeah. People don’t understand. Deeply.

Did the other kids make fun of you?

They made whinnying sounds when I walked by…And karate saved my life.  On my show there’s this little boy, Elijah, who is huge—14 years old and 6 foot 5. He beats himself and calls himself a ‘catastrophic failure.’ And I’m like, ‘Elijah, the minute you stop treating yourself like this, they will stop treating you like this. Here’s what’s happening. You’re dealing with kids that are feeling powerless in their own life. They pick on you so they feel powerful and you feel powerless, but when you show them that you’re empowered, they know that you’re not going to be that kind of victim.’ And that’s exactly what happened with me. I was empowered.

Do you worry about gaining weight again?

Constantly. But actually not fat– I have that solidly under control. It’s injury. I’m really afraid of injury. I’m afraid of being helpless. Does that make any sense?

Totally: Powerless!

YES! It’s not fat. I’ve got that under control. It’s powerlessness. …Which is really amazing because I ride motorcycles, and every time I get on that bike I’m like, ‘What if something happens?’

What’s the hardest part of staying in shape?

Training is extraordinarily athletic, my life is athletic. But my diet—I’m not going to lie. I’m REAL good with it. I’ll have dark chocolate peanut butter cups or a brownie from my cookbook and it’s like 200 calories and it’s made with yogurt and honey and olive oil and tastes amazing.  Is it low calorie? No. But I’ll have 250 calories of it, of one brownie. My diet I can control really well.   Getting to the gym– When?  I mean: tomorrow I have to be up at –what—4:30 to do a satellite media tour. Then a press day. Then I’m on a plane to Arizona and then I have a pre-production meeting, and then I start shooting my next family and then I’ll get up the next morning and shoot a 15-hour day—easily—for 5 days in a row.

What’s your typical diet like?

Today I had an Ezekiel English muffin with almond butter and a banana on top. … Or sometimes I’ll have organic fruit with yogurt and granola, sometimes I’ll have eggs over easy with Ezekiel toast, or oatmeal with almonds and cinnamon and apples. For lunch I’ll have grilled fish with some kind of grain, like brown rice or quinoa or a salad, and then for a snack I’ll have sweets—the brownies from my cookbook, which again is no butter, no sugar—honey, olive oil—so I eat really good quality stuff. Tonight I’m going to have fresh rolls from my favorite Thai place –which is raw rice paper, shrimp and veggies.

But you don’t follow an official diet, do you?

It’s a way of life. I eat to live well now. Does that make any sense?  I eat to not get breast cancer.  I eat to not drop dead of a heart attack. I’m terrified of injury—I live in fear of the day when the doctor says, ‘We found a lump.’ I’m not kidding.

I have that same fear. So what’s your guilty pleasure?

The occasional glass of tequila or red wine. I don’t drink much so, when I do it’s a guilty pleasure.

Do you have one message you’d like to give viewers?

The message is that your dreams are your destiny, and with the right tools in place you can create any reality you choose for yourself. Live well. I’m helping people build a life, not a body.