Background: A new diagnostic framework for clinical obesity, proposed by the Lancet Commission, defines obesity as excess adiposity with organ dysfunction, offering a more functional assessment than traditional body mass index (BMI)-based classification. However, it has not been applied to Asian populations, where obesity-related complications arise at lower BMI thresholds. Methods: We analyzed 57,863 Korean adults aged ≥20 years from the 2014 to 2023 Korea National Health and Nutrition Examination Survey (KNHANES), a nationally representative, cross-sectional dataset. Clinical obesity was defined as excess adiposity with ≥1 obesity-related complication or functional limitation; preclinical obesity was defined as excess adiposity without complications. Age, sex, and temporal trends were examined and compared with BMI-based classifications using complex sampling weights and age-standardization. Results: The prevalence of clinical obesity and preclinical obesity was 31.2% and 8.1%, respectively. Among those with BMI-defined obesity (≥25.0 kg/m²), 20.1% had no complications, while 19.4% of overweight individuals (BMI 23.0–24.9 kg/m²) met clinical obesity criteria. Clinical obesity increased with age despite stable BMI, driven by metabolic and functional decline. Cancer prevalence was highest among individuals with clinical obesity (1.77%). Applying Western waist circumference cutoffs drastically reduced the estimated prevalence of clinical obesity to 13.1%. Longitudinal analyses showed a rising trend in clinical obesity over ime. Conclusion This is the first large-scale study to apply the clinical obesity framework in an Asian population. The framework identifies high-risk individuals missed by BMI al

The worldwide prevalence of obesity is a key factor involved in the epidemic proportions reached by chronic societal diseases. A revolution in the study of obesity has been the development of imaging techniques for the measurement of its regional distribution. These imaging studies have consistently reported that individuals with an excess of visceral adipose tissue (VAT) were those characterized by the highest cardiometabolic risk. Excess VAT has also been found to be accompanied by ectopic fat deposition. It is proposed that subcutaneous versus visceral obesity can be considered as two extremes of a continuum of adiposity phenotypes with cardiometabolic risk ranging from low to high. The heterogeneity of obesity phenotypes represents a clinical challenge to the evaluation of cardiometabolic risk associated with a given body mass index (BMI). Simple tools can be used to better appreciate its heterogeneity. Measuring waist circumference is a relevant step to characterize fat distribution. Another important modulator of cardiometabolic risk is cardiorespiratory fitness. Individuals with a high level of cardiorespiratory fitness are characterized by a lower accumulation of VAT compared to those with poor fitness. Diet quality and level of physical activity are also key behaviors that substantially modulate cardiometabolic risk. It is proposed that it is no longer acceptable to assess the health risk of obesity using the BMI alone. In the context of personalized medicine, precision lifestyle medicine should be applied to the field of obesity, which should rather be referred to as ‘obesities.’

The worldwide prevalence of obesity is a key factor involved in the epidemic proportions reached by chronic societal diseases. A revolution in the study of obesity has been the development of imaging techniques for the measurement of its regional distribution. These imaging studies have consistently reported that individuals with an excess of visceral adipose tissue (VAT) were those characterized by the highest cardiometabolic risk. Excess VAT has also been found to be accompanied by ectopic fat deposition. It is proposed that subcutaneous versus visceral obesity can be considered as two extremes of a continuum of adiposity phenotypes with cardiometabolic risk ranging from low to high. The heterogeneity of obesity phenotypes represents a clinical challenge to the evaluation of cardiometabolic risk associated with a given body mass index (BMI). Simple tools can be used to better appreciate its heterogeneity. Measuring waist circumference is a relevant step to characterize fat distribution. Another important modulator of cardiometabolic risk is cardiorespiratory fitness. Individuals with a high level of cardiorespiratory fitness are characterized by a lower accumulation of VAT compared to those with poor fitness. Diet quality and level of physical activity are also key behaviors that substantially modulate cardiometabolic risk. It is proposed that it is no longer acceptable to assess the health risk of obesity using the BMI alone. In the context of personalized medicine, precision lifestyle medicine should be applied to the field of obesity, which should rather be referred to as ‘obesities.’

The worldwide prevalence of obesity is a key factor involved in the epidemic proportions reached by chronic societal diseases. A revolution in the study of obesity has been the development of imaging techniques for the measurement of its regional distribution. These imaging studies have consistently reported that individuals with an excess of visceral adipose tissue (VAT) were those characterized by the highest cardiometabolic risk. Excess VAT has also been found to be accompanied by ectopic fat deposition. It is proposed that subcutaneous versus visceral obesity can be considered as two extremes of a continuum of adiposity phenotypes with cardiometabolic risk ranging from low to high. The heterogeneity of obesity phenotypes represents a clinical challenge to the evaluation of cardiometabolic risk associated with a given body mass index (BMI). Simple tools can be used to better appreciate its heterogeneity. Measuring waist circumference is a relevant step to characterize fat distribution. Another important modulator of cardiometabolic risk is cardiorespiratory fitness. Individuals with a high level of cardiorespiratory fitness are characterized by a lower accumulation of VAT compared to those with poor fitness. Diet quality and level of physical activity are also key behaviors that substantially modulate cardiometabolic risk. It is proposed that it is no longer acceptable to assess the health risk of obesity using the BMI alone. In the context of personalized medicine, precision lifestyle medicine should be applied to the field of obesity, which should rather be referred to as ‘obesities.’