Diagnostic Criteria of Obesity as per 2022 Update of Clinical Practice Guidelines for Obesity by the Korean Society

Obesity is a chronic condition marked by excessive body fat and a high body mass index (BMI), which is calculated by dividing weight in kilograms by height in meters squared. The prevalence of obesity has been rising steadily over the past 11 years, leading to a range of associated health issues. Diagnosing obesity is crucial, as it determines the need for treatment.

This review focuses on the diagnostic criteria for obesity as laid out in the 2022 Clinical Practice Guidelines by the Korean Society for the Study of Obesity (KSSO). BMI serves as a key measure for defining obesity due to its strong correlation with body fat and obesity-related health problems, such as diabetes and hypertension. The World Health Organization (WHO) classifies a BMI of 25 kg/m² and above as overweight, and 30 kg/m² and above as obese. However, Asian populations, including Koreans, face higher risks of related diseases at lower BMI thresholds, necessitating adjusted classifications: a BMI of 23 kg/m² is considered overweight, and 25 kg/m² is considered obese.

The KSSO's analysis revealed that the risk of conditions like type 2 diabetes and hypertension increases steadily with BMI, particularly in the 23-25 kg/m² range. Hence, the KSSO defines overweight and obesity as BMI ≥23 kg/m² and ≥25 kg/m², respectively, emphasizing the importance of morbidity over mortality in diagnosing obesity.

Stages of Obesity:

The KSSO classifies obesity in adults based on an increase in obesity-related comorbidities according to the BMI level, which is as follows:

Abdominal Obesity Diagnosis:

In Korea, abdominal obesity is determined by waist circumference (WC), with thresholds set at ≥90 cm for men and ≥85 cm for women. Since BMI alone does not accurately reflect body fat, especially in certain populations, the KSSO recommends using both BMI and WC measurements to assess obesity. Research indicates that WC is a better predictor of cardiovascular diseases and other related health issues than BMI alone.Thus, integration of these criteria aims to enhance the management of individuals at risk for obesity-related health issues.

Source: Haam JH, Kim BT, Kim EM, Kwon H, Kang JH, Park JH, Kim KK, Rhee SY, Kim YH, Lee KY. Diagnosis of Obesity: 2022 Update of Clinical Practice Guidelines for Obesity by the Korean Society for the Study of Obesity. J Obes Metab Syndr. 2023 Jun 30;32(2):121-129. doi: 10.7570/jomes23031. PMID: 37386771; PMCID: PMC10327686.