Ethnic Differences in Body Composition
At the same body mass index, people of Chinese, Malay and South Asian ancestry tend to carry more body fat than people of European ancestry, which is why Singapore uses the lower BMI action points of 23 and 27.5.
Plain English
Patient-Friendly Explanation
Body mass index is a proxy. It measures weight for height, and it assumes that two people of the same height and weight carry a similar amount of fat. Often they do not, and in Singapore that difference was measured rather than assumed. Local researchers studied 291 adults of Chinese, Malay and Indian ancestry whose body fat was measured with the most accurate method available, a four-compartment model that combines body water, body density and bone mineral content. When the equations normally used in European populations were applied to them, those equations understated their body fat by roughly three to six percentage points. The three groups also differ from one another: for the same body mass index, Indians carried the most body fat and Chinese the least. The consequence is practical. The weight-for-height number at which a person here reaches the body fat of a European with a body mass index of 30, the conventional threshold for obesity, is much lower, about 27 for Chinese and Malays and about 26 for Indians. That is the reason the health authorities in Singapore use action points of 23 and 27.5 rather than the international 25 and 30, and the reason a body mass index of 26 deserves attention even though a chart printed elsewhere would call it normal. None of this means ancestry decides your weight or your health. It means the same number on the scale can represent a different amount of fat in different people. Two other measurements matter as much: waist circumference, which captures the fat around the organs, and the trend over months, which tells you where you are going rather than where you are.
Medical
Clinical Definition
The relationship between body mass index and body fat percentage is population-specific, and the thresholds used in Singapore rest on local measurement. Deurenberg-Yap and colleagues studied 291 adults selected to span the adult range of age and body mass index and measured body fat with a four-compartment model: total body water by deuterium oxide dilution, body density by air-displacement plethysmography, and bone mineral content by dual-energy X-ray absorptiometry. A prediction equation derived in a Caucasian population underestimated body fat in Singaporean Chinese, Malays and Indians, with mean errors of 2.7 to 5.6 body-fat percentage points, and the body mass index to body fat relationship differed among the three groups, with Indians having the highest and Chinese the lowest fat content at any given index. The authors calculated that matching the body fat of a Caucasian at a body mass index of 30 would require an index of approximately 27 in Chinese and Malays and 26 in Indians. A parallel analysis of the 1998 National Health Survey, 4,723 adults with a 291-subject body composition subsample, found that at a body mass index of 22 to 24 and waist circumferences of 75 to 80 centimetres in women and 80 to 85 centimetres in men, the absolute risk of carrying at least one cardiovascular risk factor was 41 to 81 per cent and the relative risk 1.97 to 4.38 compared with the reference category, all below the cut-offs then recommended internationally. These data supported the additional public health action points of 23 and 27.5 kilograms per square metre for Asian populations adopted by the World Health Organization in 2004 and applied in Singapore. The mechanisms proposed include differences in body build, with a shorter sitting height relative to stature, a more central distribution of fat, and a greater proportion of fat relative to skeletal muscle at any given weight, together with differences in how much of that fat is visceral. The clinical implications are that the index must be read against local thresholds, that waist circumference should accompany it, and that a single number should not decide whether someone needs assessment: the distribution of fat, the metabolic markers and the trajectory over time carry more information.
Key Insight
Why It Matters
A body mass index of 26 means something different in Singapore than the same number read against a European chart, and the local action points of 23 and 27.5 exist because the fat-to-index relationship was measured in this population.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: October 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
