Yes. If your family background is South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean, NICE recommends lowering the BMI cut-offs by 2.5 points. Increased risk begins at 23 rather than 25, and high risk at 27.5 rather than 30.
It is one of the clearer pieces of UK guidance and one of the most commonly missed, because applying it depends entirely on someone thinking to ask the question.
What the adjusted thresholds are
The adjustment applies to people from a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background (NICE, 2025).
In practice this means someone with a BMI of 28 might be assessed as overweight against one set of numbers and as high risk against the other. Same person, same measurement, different clinical picture.
Why the numbers are different
BMI is a measure of weight relative to height. It says nothing about what that weight is made of or where it sits.
At any given BMI, people from these backgrounds tend on average to carry more visceral fat — the fat stored around the organs — and less muscle mass than white European populations. Visceral fat is the tissue most strongly associated with insulin resistance, type 2 diabetes and cardiovascular disease.
The result is that health risk arrives at a lower number. A BMI of 27 in a South Asian adult can carry a comparable metabolic risk to a BMI of 30 in a white European adult.
This is not a new observation. A World Health Organization expert consultation set out the case for lower Asian thresholds in 2004, and UK guidance has reflected it for over a decade (WHO, 2004; NICE, 2022).
Why it gets missed
The guidance is clear. The gap is usually in how services are built rather than in what they know.
An online assessment can only apply a threshold it has the information for. If the questionnaire asks height, weight and medical history but never asks about family background, there is no way to make the adjustment — and the person is measured against a threshold that was not designed for them.
The consequence runs in both directions. Someone can be turned away from care they would benefit from because their BMI reads as 28 rather than 30. Or the reverse: a risk profile that warrants closer monitoring gets treated as routine.
What this means for you
If your family background is one of those listed, the numbers that apply to you are 23 and 27.5.
That does not mean treatment is automatically appropriate at 27.5, any more than it is automatically appropriate at 30. BMI is the entry point to an assessment, not the assessment itself. Your medical history, current medicines, previous experience and personal goals all sit alongside it.
What it does mean is that any service assessing you should have asked. If it did not, that is worth noting.
If you have a mixed background
Guidance does not currently set out a separate approach for people of mixed heritage, and clinicians generally apply judgement rather than a formula.
The practical answer is to say so during your assessment. A clinician can then weigh it alongside everything else, which is a better outcome than a questionnaire making an assumption either way.
BMI is your weight in kilograms divided by your height in metres squared. Someone who is 1.7m and 82kg has a BMI of 28.4.
It is a screening measure, not a diagnosis. It was designed to describe populations, and it does that job reasonably well. Applied to one person it is a useful first filter and very little more.
A useful second measure
Because BMI has these limitations, waist measurement is often used alongside it.
NICE suggests waist-to-height ratio as a straightforward check: for most adults, keeping your waist to less than half your height is a reasonable guide. It is not affected by the same population differences as BMI, and it gives a rough indication of central fat that BMI alone cannot.
You can calculate your BMI and read more about what BMI you need for weight management treatment.
What happens next
If you would like a clinician to assess whether treatment is appropriate for you, the adjusted thresholds are applied as part of that. We ask about family background because we cannot apply the guidance properly without it.
Frequently asked questions
Which ethnic backgrounds have lower BMI thresholds? South Asian, Chinese, other Asian, Middle Eastern, Black African and African-Caribbean family backgrounds. NICE recommends reducing the standard cut-offs by 2.5 points for these groups.
What is the BMI threshold for South Asian people? Increased risk begins at a BMI of 23 and high risk at 27.5, rather than 25 and 30.
Why do South Asian people have a lower BMI threshold? At the same BMI, South Asian populations tend on average to carry more visceral fat and less muscle mass. Visceral fat is the tissue most closely linked to type 2 diabetes and cardiovascular disease, so risk arrives at a lower number.
Do lower thresholds mean I definitely qualify for treatment? No. A BMI in range means an assessment is appropriate, not that treatment is. Your medical history and circumstances form part of the decision.
What if I am of mixed heritage? Current guidance does not set a separate threshold. Tell the clinician assessing you and they will take it into account alongside everything else.
Does this apply to children? No. BMI is assessed differently in children and young people, using centile charts rather than fixed thresholds.
References
National Institute for Health and Care Excellence (2025) Overweight and obesity management. NICE guideline NG246. London: NICE.
National Institute for Health and Care Excellence (2022) Obesity: identification, assessment and management. Clinical guideline CG189. London: NICE.
World Health Organization Expert Consultation (2004) 'Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies', The Lancet, 363(9403), pp. 157–163.
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