What is the definition of morbid obesity in Asians?

From the Guidelines

Morbid obesity in Asians is defined as a Body Mass Index (BMI) of 27.5 kg/m² or higher, which is a lower threshold compared to Western populations. This definition is based on the most recent and highest quality study available, which suggests that Asian populations tend to have higher body fat percentages and greater risk of obesity-related health complications at lower BMI values compared to Western populations 1. The study, published in 2023 in the journal Obesity Reviews, proposes threshold values of BMI ≥ 23 kg/m2 for overweight and BMI ≥ 25 or ≥27.5 kg/m2 for obesity in South and Southeast Asian countries.

Key Points to Consider

• The World Health Organization and various Asian health organizations have recognized these ethnic differences in body composition and metabolic risk 1.
• Using Western BMI cutoffs in Asian populations would underestimate obesity-related health risks and delay necessary interventions.
• Healthcare providers should use these adjusted BMI thresholds when assessing Asian patients to ensure appropriate screening and management of obesity-related conditions such as type 2 diabetes, hypertension, and cardiovascular disease.
• The proposed BMI cut points for obesity in Asian populations are generally lower than those for Western populations, with a threshold of BMI ≥ 27.5 kg/m² being considered obese in many Asian countries 1.

Importance of Ethnic-Specific Definitions

The use of ethnic-specific definitions for obesity is crucial in clinical practice, as it allows for more accurate assessment and management of obesity-related health risks in Asian populations. The study published in 2023 in Obesity Reviews highlights the importance of considering the unique body composition and metabolic profiles of Asian populations when defining obesity 1. By using these adjusted BMI thresholds, healthcare providers can provide more effective and targeted care for Asian patients, ultimately improving their morbidity, mortality, and quality of life.

From the Research

Definition of Morbid Obesity in Asians

• Morbid obesity is generally defined as a Body Mass Index (BMI) of 40 or higher, or a BMI of 35 or higher with serious obesity-related comorbidities 2.
• However, for Asian populations, the BMI cut-off points for defining overweight and obesity should be lower due to the higher metabolic risks at a given BMI compared to Caucasians 3, 4, 5.
• The World Health Organisation (WHO) and other organizations recommend lower BMI cut-off points for obesity in Asian people, such as BMI ≥25.0 or ≥27.5 kg/m2, instead of the standard ≥30.0 kg/m2 threshold 4, 5.

BMI Cut-off Points for Asians

• Several studies have identified the BMI cut-off points for Asian populations to be lower than the international BMI cut-off points recommended by the WHO 5.
• The International Association for the Study of Obesity (IASO), the International Obesity Task Force (IOTF), and the WHO have recommended BMI cut-off points for Asian populations, but further research is needed to develop country-specific and ethnic-specific cut-off points 5.
• A study proposed evidence-based ethnicity-specific action points for public awareness, screening, and treatment, taking into consideration sensitivity, specificity, and positive/negative predictive values for cardiovascular disease and/or metabolic syndromes 3.

Management of Obesity in Asians

• Lifestyle modification is recommended as the cornerstone of obesity management, but many patients do not achieve long-lasting benefits due to difficulty with adherence and physiological and neurohormonal adaptation of the body in response to weight loss 6.
• Bariatric surgery yields substantial and sustained weight loss with resolution of type 2 diabetes, although it is generally recommended for patients with severe obesity due to the high cost and small risk of serious complications 6, 2.
• Asian-specific parameters for assessing obesity should become a standard part of clinical practice, and Asian American people should be offered subgroup-specific tailored interventions due to the heterogeneity of this population 4.