Some kids dream of becoming firefighters. Others fantasize about joining the circus. As a child, Heather Zehring always imagined she’d grow up to be fat.

“My brother and I used to play fat people when we were young,” says Zehring. “We would pretend to be fat people leaving the grocery store. We’d bump into each other and our pretend groceries would spill all over and we’d fall on the floor. So I guess it’s karma coming back and punishing me.”

Zehring was actually an average-sized kid. But by the age of 27, her childhood premonition had come true and she weighed more than 300 pounds.

Embarrassed by her size, she’d wait until midnight to go grocery shopping. She didn’t want to share the aisles with the spandex-clad women who stopped by the supermarket after their morning workouts. And she didn’t want crowds of people trying to peek into her cart to see what kinds of foods fat people buy.

“I bought a lot of sheet cakes,” says Zehring.”Sometimes I would buy candles with the sheet cake, trying to trick people into believing I wasn’t just buying the cake for myself. Once I got a sheet cake and asked the people in the bakery department to write somebody’s name on it in frosting. Of course, it wasn’t anybody’s birthday. I was just going to inhale that cake when I got home. But I was so worried that the people at the store would know the truth.”

That anxiety, though, was nothing compared to her fear of dying at a young age. She knew overweight individuals were at risk for everything from high blood pressure to heart disease. And she knew her affection for food was becoming dangerous.

“I knew that there were some people somewhere who don’t have this attachment to food — people who eat food when they’re hungry. And when they’re not hungry anymore, they stop eating,” says Zehring. “For me, it was about satisfying something else. My comfort and my safety and my solace was food.”

At the age of 29, Zehring went in for laparoscopic gastric bypass surgery. Doctors reduced her stomach to the size of an egg to restrict the amount of food she could take in.

Fifteen months ago, Zehring weighed 312 pounds. She couldn’t climb more than eight stairs at a time. And she crossed her fingers that the 4XL shirts she bought over the Internet would fit.

Today she weighs 156 pounds. She can’t believe how close her bones are to her skin. And, much to her constant surprise, she can now bake blueberry muffins without feeling the need to devour them all the minute they come out of the oven.

“When I passed from morbidly obese to obese, I was thrilled. When I became merely overweight, I thought, ‘My God, this is something else,'” she says. “And when I became a size 18, I really thought I was a supermodel. I really thought that was the greatest thing in the world.”

Although she’s thrilled by her new size, Zehring sometimes misses the soft rolls of fat that used to hang from her sides. She says they were the perfect excuses for why she didn’t have that high-paying job or that ideal husband. But now that they’re gone, fitting into the world is much easier.

“I didn’t like to sit outside at restaurants because they always have those plastic chairs outside and I was afraid they would break if I sat in them,” says Zehring. “Airplane seats were the worst. Some airplane seat belts wouldn’t buckle. I’d have to get an extender. When I’d get off the plane, I’d pull the seat belt tight so it looked like I had been able to buckle it and have extra room. I didn’t want the evidence  just sitting out there in the open of just how much girth I had.”

When she was overweight, Zehring assumed people would look at her in disgust. But, in reality, they just didn’t look at her at all.

“I did feel kind of invisible sometimes. I felt like I could go in and out of the crowd without being noticed. Kind of like a superhero. A really fat superhero,” she says.

Today, Zehring works at Woodbury Elementary School as a teacher’s aide. It’s a job she never would’ve considered a year ago. In fact, she was uncomfortable pursuing most forms of employment.

“The thing that would always stop me was the thought of having to buy clothes for the job,” says Zehring. “There’s a point where it doesn’t matter if your stripes are horizontal or vertical, you’re still going to look fat. I didn’t want to have to put on skirts that had waists the size of kiddie swimming pools. And I didn’t want to have to wear nylons because I didn’t want my thighs to be scratching against each other as I walked down the hall.

“I feel more useful now. It’s not necessarily the fat that dragged me down. It’s everything that got me to being so fat that dragged me down. That became symbolic. When I lost that, I was able to deal with a lot of other things. I came out of my cocoon.”

Like any major operation, gastric bypass surgery comes with serious risks. Up to 20 percent of patients need followup procedures to address complications. Zehring’s been lucky. Her biggest challenge is remembering she no longer weighs more than 300 pounds.

“I still walk really slowly. I still shuffle my feet. I still walk like a fat girl. I wonder when it’s going to wear off,” she says.

“Even though I’m not really fat anymore, I identify with fat people more than any other person. They’re my race, fat people. And I think I’ll always feel that way.”