(CNN) -- Regina Lopez ran up the stairs near her home in Long Beach, California.
She hated her thighs. She hated her butt.
If other early-morning exercisers had wandered by, they would have heard her whispering to the fat on her legs: "Go away. You're going to go away."
Lopez pictured herself as a smaller person -- someone who was able to go shopping and buy the cute clothes she saw on the thrift store hangers. The mental image pushed her to do the beach stairs again despite the rising temperature.
Bad habits from an early age
Lopez and her siblings lived primarily with their grandmother when they were young. Once a month, Grammita bought groceries with money from her pension and Social Security check.
"The first of the month I would chow down," Lopez remembers, because "by the end of the month we would be barely having anything."
"Growing up poor, living off rice and beans -- if we were lucky -- had a big impact on our eating habits," says Lopez's younger sister, Francine Hernandez. "No one ever told Regina and I to 'eat your vegetables.' "
Lopez used to steal cookies out of her cousins' cupboards when she went to visit them. As the sisters got older, they started playing outside less and drinking more. They took money they earned working to splurge on the dollar menu at McDonald's.
"I developed an addiction to eating junk," Lopez says simply.
These bad habits carried into adulthood. Lopez ordered fast food for lunch every day with her co-workers. She never exercised and hated vegetables.
Once in a while she attempted to lose weight, sometimes dropping 10 or 20 pounds. But something always made her sabotage her efforts. She figured her obesity was hereditary -- her aunts were all "short, chubby little ladies with big boobs. And that's what I was."
Creative by nature, Lopez expressed her growing unhappiness in journals. She'd draw photos of a fat woman crying, with word bubbles that said things such as "I'm huge, and I hate myself."
What she hated most was shopping for clothes. She longed to buy the cute outfits she saw at swap meets or in stores but could only fit into what she calls the "Golden Girl"-type dresses sold in her size: 22/24.
At 4 feet 11 inches, Lopez weighed 224 pounds.
Lopez talked with her Art Supply Warehouse co-worker Sarah Nelson often about losing weight. In November 2011, Nelson's mother underwent heart valve replacement surgery. It was the wake-up call Nelson needed to change her eating and exercise habits.
The friends decided to start an office weight-loss competition. Lopez was embarrassed stepping up to the scale for the first time in May 2012 -- "No one wants to show that they weigh 224 pounds in front of guys" -- but the number that flashed on the scale simply reinforced her commitment.
She and Nelson began walking on their 10-minute breaks and sharing healthy recipes they found online. Lopez also used the Lose It! app to track her calorie intake. She exercised six days a week, walking on the beach for four miles or running the stairs.
It was hardest at social gatherings with her friends; they'd be drinking beer and eating burgers, while Lopez tried to stick with skinless chicken breasts and vegetables.
"My friends still love to have parties," she says. "I'm kind of like an old lady. I come home, work out, eat dinner, watch 'Golden Girls' and go to sleep."
By the end of the challenge, Lopez had lost 49 pounds. She had also lost the competition -- the winner beat her by losing just 1% more of his body weight.
"I totally cried," she remembers with a laugh. "I wasn't trying to be a sore loser, but I think I worked my butt off."
Before that fateful day, Lopez swore to Nelson she would celebrate the end of the competition with a large, cheesy pizza.
"I never got that pizza."
'You are tiny'
When Lopez showed up at her family's annual Thanksgiving dinner in 2012, she was wearing jeans for the first time in years. She was also wearing a top that was way too big for her, says Hernandez, her sister.
Lopez went shopping a few months later and called her sister to tell her the good news: She now fit into a small shirt size.
"I said, 'Regina, I told you. You are tiny,' " Hernandez recalls. "It took me forever to get used to seeing Regina so small."
Since May 2012, Lopez has lost 97 pounds. She currently weighs 127 pounds -- just two pounds short of her goal weight. She still walks or runs or climbs stairs six days a week. And on Saturdays she "treasure hunts" at the swap meet, browsing through the $1 clothing tables.
"I literally always dreamed about buying clothes and feeling good because they fit," she says. "Now it's my reality. It's an amazing feeling."
Nelson, who has also lost close to 50 pounds, says, "Regina has always been beautiful inside and out. But now her health is better than ever. She looks wonderful."
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