After This Ultrasound Technician Saw Her 'Organs Were Smothered in Fat,' She Lost 167 Lbs.

Monica Rose Villarreal realized she “was a walking, ticking time bomb” at 310 lbs. — so she worked to lose half her size

Monica Rose Villarreal remembers being 8 years old and tipping the scale at 143 lbs.

She was growing up in a household where food "was always used as a reward, as a comfort, and sometimes a punishment," and her weight increased as she got older. At age 10, Villarreal recalls in PEOPLE's Half Their Size issue, she had sciatic nerve pain, requiring pricey chiropractor appointments that strained the budget of her single mom, as did expensive plus-size clothing.

"I felt like a monetary burden because I needed extra care and extra attention," the Long Beach, California resident, now 42, says.

Through the years Villarreal continued to gain around 15 lbs. a year, eventually hitting her highest weight of 310 lbs. at age 32.

"At that point, I had a 63 in. waist and I'm only 64 in. tall," she says. "So I'm as round as I am high and I can't tie my own shoes, cannot walk very far without being out of breath and could not even really take care of my kid. I had two babies at this point, they're 3 and 4, and it was a joke that I didn't have a lap because I didn't. My stomach was all the way to my knees."

In 2007, Villarreal suddenly lost her job to the recession and was looking for a new career path. She started looking into the medical field, and decided to become an ultrasound technician.

"I envisioned scanning babies and telling people, 'It's a girl!' and having this fun time," she says. So Villarreal enrolled in the 18-month training program and found that "in order to scan babies inside of the human body, you have to learn how to scan. So we practiced on ourselves."

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And at 310 lbs., Villarreal became a popular test subject in class — "it was a joke, like, 'She has no neck, it'll be hard to scan her arteries going to her brain.' "

"This is where I actually got to see with my own eyes that my organs were smothered in fat, covered in it. And then I'm learning about how this impacts your health and it just became glaringly obvious that I was a walking, ticking time bomb," she says. "I said to myself, 'I've got to do something.' "

But it still took time for Villarreal to make a change. In 2015, she was at a medical health fair and met another vendor who had lost 100 lbs. with Optavia's weight loss program.

"I eat chicken nuggets for breakfast, I eat quesadillas for lunch and I have pizza for dinner every single night; I do not exercise, I don't care about water. Those were habits of disease, not habits of health," she says. "When he explained to me that I needed structure, and Optavia had a curriculum to break my bad habits and recreate healthier ones with a community of other people that would help me, I was in."

Shanna Fisher

Villarreal started on the program and discovered how much of her eating habits were "emotional," something she started working to correct with a tailored plan of six healthy meals a day, along with the support of her coach and community.

"I found a hiking buddy, I found a cooking friend, I found a going-on-trips person and I found encouragement," she says.

Shanna Fisher

Villarreal also got into jumping as a fun, low-impact at-home workout, first on a trampoline she bought online, and then with Kangoo Jumps classes, a unique workout with boots that help people jump up and down. "It's like Zumba on steroids," she says. "I love just the whole vibe, the cute outfits, the girls, the whole camaraderie; and that was an environment I'd never been in."

Villarreal steadily lost weight, dropping 167 lbs., and is now 143 lbs. — the same weight she was at age 8.

"I remember getting to 143 and it was just like, 'I did it.' Every time I think about it I cry," she says. "And this 143 at 42 looks way different than 143 at 8 years old."