Lifestyle Health Jazz Jennings Is 'Absolutely Horrified' She Might Not Be Able to Get Gender Confirmation Surgery Jazz Jennings must lose 30 lbs. to undergo gender confirmation surgery By Natalie Stone Published on January 9, 2018 10:00 AM Share Tweet Pin Email Jazz Jennings' lifelong dream of undergoing gender confirmation surgery may not be possible for the transgender teen. The 17-year-old TLC star and LGBTQ rights activist has been mentally readying to undergo surgery, but now she's been informed that she must also physically prepare — but it might take longer than she expected. In a PEOPLE sneak peek at Tuesday night's episode of I Am Jazz, Jennings and her parents visit her doctor, who delivers some bad news. "I saw Jazz and her folks about six months ago and that was actually the first time I've gotten to examine Jazz, so I called the Jennings today because I've been speaking with colleagues and I wanted to get their take on a number of issues," Jennings' surgeon Dr. Marci Bowers explains. "I wanted to follow-up with you in person just because your surgery will be very difficult in terms of what even the most experienced surgeons have encountered," she tells Jennings. "Not to bring up the bad news first, but you gained in your BMI — which is called body mass index — which basically looks at your weight compared to your height. If we're going to get a hospital to say, 'we're going to allow a surgery at age 17,' you're going to have to be at a lower BMI. Literally, they won't approve it if your BMI is one dot over. When it translates to pounds, it's about 30 pounds." 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. WATCH: Jazz Jennings Responds to Derick Dillard's Transphobic Tweet: 'Every Day I Experience Cyber-Bullying' Upon learning that she is required to lose 30 pounds to be approved for surgery, Jennings is fearful that her dream may not become a reality. "The fact that I might not be able to get the surgery if I don't lose 30 pounds, I am absolutely horrified," she share. "I knew that my weight was a problem, but I didn't realize that it could affect something that I've been waiting for my entire life." Bowers continues to explain that a surgery candidate could be denied if their BMI is too high because "if there's more weight, it makes the surgery longer and it makes it more difficult." The surgeon adds: "What we're finding is that as one new technology emerges, like hormone blockade — nobody thought we could block puberty — it creates another problem elsewhere. Now we don't have enough tissue to create the adult genitals of the opposite sex." In the season 4 super tease of the reality series, Jennings opened up about her battle with overeating. "My eating habits are beyond my control," she admitted. I Am Jazz airs Tuesdays (10 p.m. ET) on TLC.