[Column] ‘I'm in my early 20s, should I have bariatric surgery?’

A red-faced man in his early 20s walked into my office with his middle-aged mother. She looked familiar, but I couldn’t quite place her. The mother said, “Doctor, don’t you remember me? You performed my surgery two years ago.” I replied, “Ah, I recognize you by the sound of your voice. I hope you’ve been doing well.”

This time, she brought her son because she had come to realize just how much her life had changed since undergoing bariatric surgery. Her son was about to join the military, and she said she had talked to him enough -- now, she wanted him to have the surgery as soon as possible.

But when his mother mentioned scheduling the surgery, his expression darkened noticeably. He asked, “Am I good enough for surgery?” At the time, he was 21 years old, weighed 109 kilograms, had a BMI of 39 kg/m², and wasn’t taking any medication.

“I thought the army could help me lose weight,” he said. “I'm still so young -- do I really need to have part of my stomach cut out now?”

The son's questions continued. I looked at him and paused for a moment. I realized that if I were in his position, deciding to undergo surgery would not be easy.

I told him that we should begin with blood tests, and if he didn’t have diabetes, we could take some time to consider surgery more carefully. I suggested that we first try aggressive medical treatment.

After they returned home, I found myself thinking about the phrase “obese enough to get surgery.” In medical terms, it refers to the clinical guidelines for bariatric surgery. Over the past 60 years, these guidelines have undergone three major revisions—first in 1997, then in 2016, and most recently in 2022.

In the 1997 and 2016 guidelines, the basic criterion of a BMI of 35 kg/m² remained unchanged, but the presence of diabetes, rather than obesity alone, became the primary factor in determining surgical eligibility. In 2022, the BMI threshold was lowered to 30 kg/m².

Modern medicine is fundamentally evidence-based, and the guidelines for bariatric surgery are no exception. These guidelines are grounded in substantial evidence, particularly considering the limitations of conventional treatments such as medications, the chronic and relapsing nature of obesity, and the progression of diabetes. In this context, surgery is often a worthwhile option. Moreover, the current guidelines remain sufficiently conservative to ensure patient safety while offering an effective solution.

When we shift the focus to adolescent obesity metabolic surgery, the reasoning remains consistent, but the recommendation becomes more assertive. The rationale is clear: adolescent obesity almost invariably progresses to adult obesity, leading to an accelerated onset of adult diseases and complications in the late 20s or early 30s. As a result, the guidelines have become more supportive of intervening earlier to break this cycle before it leads to more severe health issues.

In fact, in some countries, if a young person develops type 2 diabetes, even if they have a low BMI, they are aggressively recommended for surgery.

The mother, who had been frustrated by her son's hesitancy throughout the appointment, brightened when I told her we would monitor his progress with medication. After all, it was weight loss, not surgery, that had brought her to the clinic in the first place.

Dr. Kim Yong-jin is one of the leading authorities on bariatric surgery in Korea. He has performed more than 4,500 cases of bariatric surgery, and was the first surgeon in Korea and the fifth in Asia to be certified as a “Master Surgeon” in bariatric diabetes surgery by the U.S. Surgical Review Corporation (SRC), the world's leading surgical evaluation and certification organization. After training at Asan Medical Center, he worked as a professor of surgery at Soonchunhyang University Seoul Hospital from 2005 to 2019. He currently serves as the Director of the Obesity and Diabetes Surgery Center at H+ Yangji Hospital. -- Ed.