Formerly Obese Woman Sees Her Belly Button for the First Time in 20 Years After Weight Loss

Kim Carter Martinez started to gain weight after the tragic losses of both her parents at a young age.

“My father died when I was 12, and my mother was very sick after that and she died when I was 17,” Carter Martinez, now 41, tells PEOPLE. “I resorted to eating as a way to cope with my feelings.”

Carter Martinez’s weight reached 344 lbs. and her mobility was limited — even moreso because of her struggle with arthritis.

“My doctor told me I needed a knee replacement to rid me of the horrible pain I was having, but I was too heavy to operate on — my BMI was so high there was a chance I could die on the operating table,” she says. “He wouldn’t operate until I lost 50 lbs. That really motivated me.”

BMI, or body mass index, is a calculation that tries to categorize weight and measure body fat in adults. Since it compares weight and height, BMI does not measure body fat directly. The index is a common convention but experts consider it a flawed standard because it was not developed to include people of color.

“I didn’t want to live with that pain and with being on narcotics and being unable to do things like walk down the beach with my husband,” she continues. “I decided I was going to lose weight to have the surgery, and I did it — and kept going.”

The Oakland, California-based labor union employee started to slim down by making “a lot of small changes that added up to a lifestyle overhaul.”

“At first I gave up Starbucks and snacking and started cooking my own meals because I was eating most of my meals at restaurants or on the run,” she says. “And I did Richard Simmons videos in my garage because that was the level of physical activity I could handle — very gentle, very easy, no jumping, nothing crazy. And I was way too embarrassed to go to the gym at my heaviest weight.”

Once Carter Martinez became more comfortable cooking healthy foods, she adopted a paleo diet. She rode her bike regularly, and eventually became comfortable enough with her body to go to the gym.

“I started using the machines and incorporated strength training,” she says. “For three years, I exercised every day and went to the gym three or four times a week, and I did walking or bike riding or some kind of exercise video in the garage.”

WATCH: Oprah’s Tips to Losing Weight! Hint, it Involves Eating Bread!

With hard work and patience, Carter Martinez reached her goal weight — but because she had dropped so many pounds, she was left with loose skin on her stomach.

“When I reached my goal weight, I was very happy with how my health had improved and how my confidence had gone up and how I felt about myself, but when I looked in the mirror I had 6 lbs. of skin that was just hanging,” she says. “It felt like this constant reminder that I used to be morbidly obese and unhealthy, and I hated that.”

Carter Martinez decided to undergo skin removal surgery to remove the excess skin.

“When I went for my post-op checkup four days later and took off the compression garment and saw the results, I just started to cry,” she says. “I literally hadn’t seen my belly button in 20 years because there was so much belly fat hanging over.”

Now that Carter Martinez is down 170 lbs., she’s doing things she never thought possible.

“In San Francisco there’s a really famous 12k race called Bay to Breakers; it’s this huge part of San Francisco culture, and it’s something that I never thought I’d be able to do. I’ve actually done it twice now,” says Carter Martinez. “Being able to participate in things like that that were once so unreachable for me has been the best part of this.”

Carter Martinez says losing weight has improved her overall quality of life.

“Life was really hard before — there were so many times that I had to say no to social situations because I couldn’t walk around, but now I don’t have to say no to things anymore,” she says. “I can pick what I want to do and be able to do it.”