Diaz is 6-foot-5 and still growing. He's always been a heavy kid, but his weight has plummeted 80 pounds in eight months thanks to surgery that puts a plastic band around the upper part of his stomach. He says it has made all the difference.
"When I started losing weight, I had more energy and confidence and I started to care more about my appearance," he said.
Matt's positive outcome was repeated in the new study, which compared obese teens who had stomach banding to those on exercise and diet. Over two years, the operated teens lost an average of 76 pounds, compared to non-operated teen, who lost only 7 pounds on average.
Fat kids are getting adult diseases, such as diabetes and sleep apnea. But it's not just physical issues.
"It affects them socially and in school," said Dr. Christine Ren, of NYU Langone Medical Center. "They get bullied, they can't go into school, they need home schooling and they can't participate in gym or exercise classes."
Matt has had those bad experiences turned around by the surgery, which is done through a couple small incisions using a stomach scope. The band slows food entering the stomach and makes patients feel full faster. After surgery, eating too fast can cause vomiting. Aside from surgical risks of infection and anesthesia, there are not many side effects, and the band can be removed with another operation if it doesn't work.
Young people have to make a psychological adjustment to the band. First, they have to eat healthy foods and they have to eat small portions.
And that is a small price, if the results of the two-year study hold up.
"Two years is sufficient to see if theres going to be weight regain, but certainly you'd like to see five years at least," Dr. Ren said.
Dr. Ren says that she's pleasantly surprised that teens are better than adults at making the psychological changes needed to work with the stomach band, perhaps because they haven't had the time to develop ingrained bad eating habits. She adds that support from family and friends is critical to success.