[Sportschosun, Reporter Jang Jong-ho] Obesity is a major chronic disease affecting about 800 million people worldwide, and it is also common in the Asia-Pacific region, where two out of five adults are overweight or obese. Until now, obesity has mainly been diagnosed using body mass index (BMI), which is calculated by dividing body weight by height squared. However, BMI alone cannot show how much body fat a person has or where it is stored, making it difficult to accurately assess actual health risks.
These limitations are especially pronounced in Asians. Even when BMI is within the normal range, many Asians accumulate excessive fat in the abdomen, liver, and pancreas. This fat makes blood sugar control more difficult and impairs organ function, leading to diabetes, fatty liver disease, and cardiovascular disease. As the population ages, sarcopenic obesity, in which people have low muscle mass but high body fat, is also increasing, further raising the risk. In fact, 32% of Korean adults with a normal BMI range of 18.5 to 22.9 have been reported to be at risk for metabolic disease.
Against this backdrop, a research team led by Professor Lim Soo of the Department of Endocrinology and Metabolism at Seoul National University Bundang Hospital has published a review paper proposing a new standard to redefine obesity diagnosis in Asians for the international academic community. The study was conducted jointly with leading experts in obesity and diabetes from Japan, China, and India, and Professor Lim participated as both first author and corresponding author.
Based on the concept of "clinical obesity disease" introduced by the Lancet Commission in 2025, the researchers refined the framework to reflect characteristics specific to Asians. Under the new standard, obesity is diagnosed not simply as a weight issue, but according to whether complications are actually present. The team divided the condition into "preclinical obesity," in which a person has excess body fat but no major complications and can carry out daily life without difficulty, and "clinical obesity disease," in which complications such as dysfunction in major organs have already developed due to excess body fat.
Diagnosis of clinical obesity disease is carried out in three stages. First, doctors determine whether body fat is excessive. They then assess whether organ function is impaired before making a final diagnosis. Specifically, waist circumference, body fat percentage, blood sugar, blood pressure, cholesterol, and kidney function are evaluated together. For more precise body composition measurements, dual-energy X-ray absorptiometry, or DXA, and impedance devices using electrical resistance may be used.
The research team said treatment strategies should also differ depending on the diagnostic stage. In preclinical obesity, where no complications have yet developed, lifestyle changes such as improved diet and exercise should be used to prevent complications. In clinical obesity disease, however, complications are already progressing, so more aggressive treatment, such as GLP-1-based anti-obesity drugs or metabolic bariatric surgery, is needed. These treatments can reduce weight while also improving complications.
Until now, clinical guidelines and insurance standards have largely been based on BMI. If the newly proposed diagnostic criteria are adopted, however, Asian patients with a high disease risk despite a low BMI are expected to gain broader access to early prevention and treatment. The approach is also likely to help shift public perception of obesity from a matter of personal willpower or appearance to a chronic disease.
Professor Lim Soo said, "Even if Asians do not weigh much, visceral fat and fat in the liver and pancreas can accumulate and raise the risk of diabetes and fatty liver disease." He added, "The focus of obesity care must move away from the number on the scale and toward the amount and location of body fat, organ function, and the patient's actual health problems."
He also emphasized, "The new standard we proposed is not intended to label more people as obese, but to identify those who need treatment at an early stage and to reduce both underdiagnosis and overdiagnosis caused by defining obesity based only on BMI."
Meanwhile, the review paper was published in Nature Reviews Endocrinology (IF 39.1), a leading global journal in the field of endocrinology.
Reporter Jang Jong-ho bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
