Miss South Carolina's 110-Pound Weight Loss

Most beauty queens would not advertise that they once weighed 234 pounds.

Miss South Carolina's Bree Boyce made it her platform, and now she's on her way to competing in the Miss America pageant.

"If I hadn't gained the weight and then lost it, and didn't say anything about it, I wouldn't be helping others," said Boyce, who won the crown last Saturday. "I'm proud of it."

"I didn't necessarily choose my platform," she told ABCNews.com. "It chose me."

What makes Boyce's victory even sweeter was winning the preliminary swimsuit round.

"I never went to pool parties when I was a little girl," said Boyce, who was overweight by age 10. "So to go up on stage in a bathing suit was terrifying."

This time was different. "Right before I walked out on stage, I thought, 'This is your moment, what you've worked so hard for.'"

Over the course of three years, Boyce lost more than 110 pounds the old-fashioned way: through healthy eating and exercise.

At a news conference after the Miss South Carolina pageant, she held up a pair of faded blue, size-18 jeans she used to wear.

Bree Boyce, at 16 and close to her highest weight, with her sister behind her.

They serve as a reminder of where she came from and keep her from slipping back.

"When I think of the past and of all the hard work and how would that look to others if I gained the weight back, I just think this is something I have to keep up with," Boyce said.

The 22-year-old theater major said she began gaining weight at age 7. By 10, it was clear she had a problem. She tried every diet possible but always gained the weight back.

At 17, she had reached her highest, 234 pounds, and was having knee problems. Her doctor warned that her knees and joints couldn't handle the excessive weight and that she would have more problems in the future if she didn't slim down.

"I wanted to be a Broadway star and go to college and have a family one day," Boyce said. "My weight was hindering all those things. I decided to make a change that day."

Boyce went on an Atkins-type diet, losing 65 pounds. She competed in her high school pageant her senior year, and, even though she was heavier than the rest of the girls, she won.

Her victory was short-lived. Boyce gained the weight back and more. Then she stopped dieting and met with a nutritionist.

She reframed what she ate and why. Instead of looking at food as comfort, she viewed it as fuel. She shopped at the supermarket and learned to cook.

She got moving too. She got up every morning at 5:30 to work out.

Sharing a Goal with First Lady Michelle Obama

Today, Boyce never misses a workout and has become an avid runner, competing in races with the goal of completing her first marathon.

It may have to wait until after the Miss America competition, which takes place in Las Vegas on Jan. 14.

"Going to Miss America is a dream come true," said Boyce. "My older sister had always competed in pageants, and I was always in the background, the chubby little supportive sister. I always wanted to compete but didn't think I could because of my weight."

On her way to shedding pounds the healthy way, Boyce said someone suggested she enter her local pageant and make her weight loss journey her platform.

Boyce had lost 74 pounds by the time she won Miss Florence in 2009. The following year, she cracked the top 10 for Miss South Carolina. On July 2, she finally took the title, singing "Tu Tu Piccola Iddio" from the opera "Madame Butterfly."

Bree Boyce holding up size-18 jeans she once wore.

Now she shares her weight-loss journey and tips for healthful living with schools and other groups. She started an "Eating Healthy and Fighting Obesity" Facebook page "to inspire all ages to become healthy through good eating habits, exercise, and believing in yourself."

The page is filled with well wishes from around the world. Boyce promises to respond to all the people who have sent her messages asking for help with their own weight loss jouney.

She says her message is very relevant in a country that has seen an obesity epidemic in young people. She's hoping to work with First Lady Michelle Obama, who has corresponded with her, on tackling the problem.

"A lot of people ask me if I would change the past," Boyce said. "Then, I wouldn't have this amazing story to tell people."