Why do South Asian people carry fat around the middle at a lower BMI?
Quick answer
South Asian adults can have metabolic risk at lower BMI levels, and central fat distribution may add information that BMI misses. BMI is a screening measure, not a diagnosis; use appropriate population-specific thresholds alongside waist and other clinical risk factors.
South Asian adults can develop type 2 diabetes and cardiovascular risk at lower BMI values than some other populations. BMI is a screening measure, not a diagnosis, and waist size and other risk factors matter. NICE uses lower action points for South Asian adults; assessment should be individualized rather than based on appearance or ethnicity alone.
Why can BMI understate risk?
BMI compares weight with height, but it does not show where fat is carried or distinguish fat from muscle. At the same BMI, average body-fat percentage and central fat distribution differ between populations. Fat around internal organs is associated with metabolic risk, although no single measurement predicts an individual's future with certainty.
What thresholds are used?
NICE recommends using lower BMI thresholds to trigger consideration of overweight and obesity in people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds: overweight from 23 kg/m² and obesity from 27.5 kg/m². These are action points reflecting population-level risk, not boundaries between healthy and unhealthy people. They are not a claim that every person in a group has the same risk.
What else should be assessed?
A clinician may consider waist circumference, blood pressure, glucose or HbA1c, cholesterol, family history, age, pregnancy history and smoking. Waist-to-height ratio can help assess central adiposity for many adults; measurement and interpretation should follow local guidance. Symptoms, existing disease and personal history can justify assessment at any BMI.
Does this mean illness is inevitable?
No. Risk is influenced by many factors, including genetics, age, activity, sleep, diet, social conditions and access to care. A risk marker is not a prediction. Avoid blaming an individual or treating ethnicity as a diagnosis. Screening and prevention should be respectful and based on the whole clinical picture.
What can you do?
Ask whether diabetes and cardiovascular risk checks are appropriate for you, particularly with family history or previous high glucose. If weight management is relevant, agree on a sustainable plan that considers health, preferences and barriers. A clinician can discuss nutrition, physical activity, sleep and, when indicated, treatments. BMI alone should not determine access to care.
How should waist measurements be interpreted?
Waist measurement is a useful screening clue, not a diagnosis. Measure consistently and discuss the result in context: height, age, pregnancy history, muscle mass, medical conditions and personal preferences all matter. A clinician can explain which local thresholds apply and whether additional checks are appropriate. Do not use a population average to infer an individual person’s health.
A practical next step
If you are concerned, ask your GP or care team about blood pressure, glucose or HbA1c and cholesterol checks. Bring relevant family and personal history. Focus any plan on achievable habits and access to support, rather than appearance or blame.
Sources & further reading
Reviewed by
Dr Chinnadorai Rajeswaran
Specialist Endocrinologist · MBBS MRCP FRCP
Last Reviewed: November 2026
Read about complex severe obesity and related care.
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