ABC News' Jen Pereira reports:
Val McLeod has been fighting a war on weight for her entire life.
At her heaviest, the 54-year-old Atlanta woman said she weighed about 620 pounds.
Some days McLeod would eat more than 30,000 calories - including fried chicken, cookies, chips, ice cream and soda - in portion sizes that were large enough for three people.
"My doctor just told me, you're going to kill yourself," McLeod said in an interview with "Good Morning America."
McLeod's weight took its toll on her joints, and they started to break down under the pressure. By the time she was in her mid-20s, McLeod was using upholstery fabric to make clothes.
"I couldn't find clothes. I had gotten so large that I no longer could fit in clothing from the full-figured women stores," she said. "We would just roll out as much fabric, yards, as I needed and put elastic in the waist."
McLeod has since lost 393 pounds after making a commitment to health and wellness.
"It wasn't like I was eating and eating and didn't care about it, I tried dieting and it worked, I'd lose a few pounds, then I would gain those pounds back and more," she said.
Her wake-up call came when, in preparation for a gastric bypass surgery that would ultimately fail, she had to be weighed on a freight scale.
"I went to a nutritionist who helped me figure out what proper portion sizes were," she said. "I also started seeing a therapist, because weight loss and being overweight is as much mental, psychological as it is physical."
And she slowly started to incorporate exercise into her daily routine. When she first started walking, McLeod said, she could "barely even go a block."
She now weighs 227 pounds, and it took her 25 years to do it. She still wants to lose 50 pounds more.
Her eating habits have undergone a significant change. She no longer eats processed food, preferring a diet of fruit, vegetables and fish.
"Make one change that's healthier and the body is so intelligent, I say the body has a brain, it will respond to anything you do for it that's in the right direction," she said.