From the Guidelines
For Asian populations, the BMI threshold for obesity is typically defined as 25 kg/m² or higher, and overweight is defined as a BMI of 23 kg/m² or higher, due to the higher risk of cardiovascular disease and type 2 diabetes at lower BMI levels compared to non-Asian populations. This is based on recent evidence from the Obesity Reviews journal, which highlights the importance of using Asian-specific BMI cutoffs when assessing obesity-related health risks in Asian patients 1. The physiological reason for this difference relates to body composition variations, with Asians generally having more visceral fat (fat around internal organs) at the same BMI compared to other ethnic groups.
Key Points to Consider
- The relationship between BMI and body fat storage and distribution varies across different ethnicities, with Asians typically having BMIs that are 2–3 kg/m2 lower than Caucasians for the same body fat percentage 1.
- Asian populations have higher levels of body fat at a given BMI, especially in visceral adipose tissue, which is associated with greater health risks 1.
- Earlier intervention strategies for weight management should be considered when BMI exceeds 23 kg/m² in Asian populations, due to the increased risk of health complications such as cardiometabolic disease, cancer, osteoarthritis, sleep apnea, and depression 1.
- The use of Asian-specific BMI cutoffs is supported by epidemiological data, which demonstrate that high BMI is associated with increased risk of mortality, cardiometabolic disease, and certain cancers 1.
Recommendations for Healthcare Providers
- Use Asian-specific BMI cutoffs when assessing obesity-related health risks in Asian patients.
- Consider earlier intervention strategies for weight management when BMI exceeds 23 kg/m² in Asian populations.
- Provide ongoing support and extended treatment to maintain initial weight loss in Asian patients who have reached their treatment target.
From the Research
Definition of Obesity in Asians
- Metabolic risks are greater in Asians than Caucasians at a given body mass index (BMI) 2
- The BMI cut-off points for defining overweight and obesity should be lower for Asians 2, 3
- Roughly even-spaced multiple action points (i.e., BMIs of 23,25,27.5,30,32.5,35 and 37.5) have been advocated for managing obesity in Asians 2
Ethnic-Specific Criteria for Classification of Body Mass Index
- Definitions for overweight and obesity are universally applied using body mass index (BMI), based on morbidity and mortality data derived from white populations 3
- Several studies have shown higher body fat, excess metabolic perturbations, and cardiovascular risk factors at lower values of BMI in Asian versus white populations 3
- Definitive guidelines have been published to classify a BMI of ≥23 kg/m(2) and ≥25 kg/m(2) as overweight and obese, respectively, by the Indian Consensus Group (for Asian Indians residing in India) 3
Prevalence of Overweight and Obesity among Asian Americans
- Asian Americans have low prevalence of overweight/obesity based on standard BMI cut points yet have higher rates of diabetes 4
- Using lower BMI cut points recommended by the World Health Organization (WHO) for Asians, the prevalence of overweight/obesity is higher among Asian American subgroups in California 4
- Filipinos, Vietnamese, Korean, South Asians, and Japanese have higher diabetes prevalence at lower BMI cut points 4
Management of Obesity in Asians
- Orlistat, an inhibitor of intestinal lipase, has been available for the treatment of obesity for nearly two decades 5
- Orlistat treatment results in a placebo-subtracted reduction in body weight of around 3 kg at 1 year, and increases the likelihood of achieving clinically significant (≥5%) weight loss by around 20% 5
- Orlistat-induced weight loss also confers modest improvements in systolic and diastolic blood pressure, low-density lipoprotein (LDL) cholesterol, glycemic parameters, and progression to diabetes in people with impaired glucose tolerance 5, 6