ABC News' Liz Sintay and Katie Kindelan report:
Wiltrina Jones struggled with obesity her entire life, surrounded by the sweet treats of her native New Orleans and then working in the food industry while in high school, throughout college and then as an adult.
At her peak weight, she stopped stepping on the scale because she knew the scale didn't go above 350 pounds.
That all changed the day Jones, 43, logged on to a website created for members of her high school to reconnect. When she saw how her classmates looked, she vowed to change.
"I had two good friends that were in the band with me, and when I came across their pictures. They were fit and toned," she told "Good Morning America." "I just stood there looking at their pictures with my mouth open, actually gasping, just looking, wondering."
"I asked myself, with tears rolling down my eyes, 'How come they look like that and I look like this, and we're the same age?'" she said. "And that made me want to change my life. I wanted to be fit. I wanted to be healthy. I didn't wanna look like I looked anymore."
Jones, who now lives outside Atlanta and works as a dog groomer, began her weight loss slowly, walking on the treadmill at the gym for 30 minutes a day and making small changes in what she ate. Within five months, she'd lost 68 pounds.
That weight loss was quickly undone by a knee injury that sidelined her for 10 months and caused her to regain the 68 pounds, plus a few more. When the doctor told her she would need surgery if things didn't improve, Jones vowed to get healthy again.
Motivated by a friend, she followed a no-carb diet for 30 days, and then began to figure out ways to incorporate carbohydrates back into her food plan so she could turn her gains into a lifestyle, not a diet.
"I started creating recipes, and I started adding a little bit of carbs, just a little bit of flavor to the food that I was preparing," she said. "And, in turn, I was able to do that for an extended amount of time. Everything I did was through trial and error."
Next, Jones tackled her fitness, returning to the gym and taking on something new, weight-lifting. While it didn't happen overnight, Jones eventually saw definition in her arms and legs and was encouraged by her fellow gym-goers to start competing in bodybuilding competitions.
"I always said, 'Well, no, no, I'm not doing that,'" Jones said. "And one day, I was just working out in the mirror, as I do every day, and I was just looking at myself, as I do every day and I said, 'Why not? You're going to sculpt your body and just sculpt it for nothing? Why not compete?'"
"So, when the competitors came in one day, I said, 'I'm going to do it. I'm going to compete,'" she said. "And I've been on the track of competing ever since."
For the past 11 months, Jones has followed a workout routine that sees her in the gym six days a week, two times a day, for a total of at least six hours a day.
She also follows a meal plan that allows her to eat the same foods she's always enjoyed, just baked in a more healthy way and served in smaller portions. Instead of fried chicken she'll have baked chicken, and instead of an all-you-can-eat buffet, she'll use a saucer round as a plate.
"The main thing you want to do is to watch your fat, watch your carbs and watch your calories," she said. "If you control those three things, you're going to lose weight. That's what I've learned."
Jones now wants to use what she's learned to build a career from her passion -- fitness -- and help other people achieve what she has.
"I want to teach people how to live healthier lifestyles, how to eat, and I want them to know it can be done," she said. "If I could do it, absolutely anybody in this world can do it."
Another thing that helps spur weight loss, Jones said, is having your own personal cheerleader to encourage and cheer you on, something she happens to have in the form of her mother.
"My mom gets on the bus with the book [of Jones's photos] and she will show everybody that's on that bus my pictures. She'll start with the bus driver," she said. "She is my biggest cheerleader, and she always tells me how proud she is of me that I have turned my life into a healthier lifestyle."