Metabolic health
A healthy waist size for a South Asian body
In short. For South Asian adults, the International Diabetes Federation sets the waist limit at 90 cm (about 35½ inches) for men and 80 cm (about 31½ inches) for women, lower than the European figures. A simpler rule works across heights and ethnicities: keep your waist to less than half your height, a waist-to-height ratio under 0.5. In one Sri Lankan study, a waist of about 76 cm (30 inches) best picked out adults with a cluster of cardiovascular risk factors.
A man of 45 steps on the scale. 65 kg, a BMI of 22.5, a reading most people would call fine. Nobody puts a tape round his waist.
It measures 94 cm (37 inches). On a South Asian body, that is past the limit linked to a higher risk of diabetes and heart disease, and the scale has no way of showing it.
Why the waist and not the weight
Weight and BMI count all of the body at once: muscle, bone, fat under the skin, fat around the organs. They cannot say where the fat sits. The waist can, at least roughly, and fat carried around the middle is the kind most closely linked to insulin resistance, triglycerides of 150 mg/dL or more and a blood pressure of 130/85 or higher.
This matters more in South Asia because risk arrives at a lower weight. A WHO expert consultation found that in Asian populations the risk of diabetes and heart disease is already raised below the international BMI cut-off of 25, and set 23 as the point at which to act. A body can be ‘normal’ by the scale and carry its risk at the waist.
The numbers: 90, 80 and lower still
The International Diabetes Federation sets the waist limit for South Asian adults at 90 cm (35½ inches) for men and 80 cm (31½ inches) for women. For Europeans the figures are 94 cm and 80 cm. On those Asian limits, 26.2% of Sri Lankan adults were centrally obese in the national Sri Lanka Diabetes and Cardiovascular Study (2005–06).
Sri Lankan data suggest the line may sit lower again. In a nationally representative sample of 4,474 adults, the waist that best separated people with two or more cardiovascular risk factors from those without was about 76 cm, in men and women alike. That is 14 cm below the IDF limit for South Asian men, and 4 cm below the limit for women.
One study is not a guideline, and 76 cm has not been adopted as one. But it points the same way as everything else here: the European figures sit too high for this population.
Half your height: the simpler rule
Waist-to-height ratio is the waist divided by the height, both in centimetres. NICE, the UK guideline body, advises keeping it under 0.5, which means a waist of less than half your height, and uses three bands for adults of both sexes and all ethnicities with a BMI under 35:
- 0.40 to 0.49: healthy
- 0.50 to 0.59: increased risk
- 0.60 or more: high risk
It travels well because it adjusts for height, which a single waist limit cannot. A meta-analysis of 31 studies and more than 300,000 adults found waist-to-height ratio a better screening tool for cardiometabolic risk than BMI, and better than waist circumference for diabetes, raised blood pressure and cardiovascular disease. The margins were modest.
| Height | Healthy, under 0.5 | Increased, 0.5 to 0.59 | High, 0.6 or more |
|---|---|---|---|
| 150 cm | under 75 | 75 to 89.9 | 90 or more |
| 155 cm | under 77.5 | 77.5 to 92.9 | 93 or more |
| 160 cm | under 80 | 80 to 95.9 | 96 or more |
| 165 cm | under 82.5 | 82.5 to 98.9 | 99 or more |
| 170 cm | under 85 | 85 to 101.9 | 102 or more |
| 175 cm | under 87.5 | 87.5 to 104.9 | 105 or more |
| 180 cm | under 90 | 90 to 107.9 | 108 or more |
The man on the scale is 170 cm tall. His 94 cm waist gives a ratio of 0.55. Increased risk, at a BMI of 22.5.
How to measure your waist
Where the tape goes changes the number by several centimetres, so the method matters more than the tape.
- Stand upright, feet together, with the tape on bare skin or a single thin layer.
- Find the bottom of your lowest rib and the top of your hip bone, on your side.
- Place the tape midway between the two, which is usually just above the navel, not at the trouser line.
- Keep the tape level all the way round and snug, without pressing into the skin.
- Breathe out normally and read the number at the end of the breath.
- Measure twice. If the two readings are within 1 cm, use the average; otherwise measure again. Divide by your height in centimetres for the ratio.
What the tape cannot tell you
A waist measurement cannot separate fat around the organs from fat under the skin. It is a proxy, and whether South Asians carry more fat around the organs at the same waist size is still debated; the imaging studies do not all agree.
It is also not a diagnosis. A waist of 85 cm says where to look, not what will be found. The looking is done in the blood: HbA1c, triglycerides, HDL and, often before glucose moves at all, fasting insulin. The NICE bands were set for adults with a BMI under 35, and a waist measured in pregnancy cannot be read against them.
Where it fits in a health review
Waist and height are measured at the consultation, by the method above, alongside blood pressure, a resting ECG and grip strength. On Essential, the waist-to-height ratio is one of the nine inputs to the metabolic age. On both programmes it is read beside the blood results it tends to predict, and measured again at the next visit to see which way it is going.
Frequently asked questions
What is a healthy waist size for a South Asian man?
The International Diabetes Federation sets the limit at 90 cm (about 35½ inches) for South Asian men, below the 94 cm used for European men. A waist under half your height is a simpler target that adjusts for height: under 85 cm (33½ inches) at 170 cm tall.
What is a healthy waist size for a South Asian woman?
The International Diabetes Federation sets the limit at 80 cm (about 31½ inches) for South Asian women. By the half-your-height rule, a woman 155 cm tall should aim for a waist under 77.5 cm (30½ inches).
Is waist-to-height ratio better than BMI?
For cardiometabolic risk, it is a better screening tool on average. A meta-analysis of 31 studies found waist-to-height ratio outperformed BMI across cardiometabolic risk as a whole, and waist circumference for diabetes, raised blood pressure and cardiovascular disease, by a modest margin. NICE advises measuring it alongside BMI in adults with a BMI under 35.
Where exactly should the waist be measured?
Midway between the bottom of the lowest rib and the top of the hip bone, usually just above the navel, at the end of a normal breath out. Not at the trouser line, which sits lower and gives a different number.
The scale gives one number and it is the wrong one to stop at. A tape, a height and a few blood tests say more about where a South Asian body is heading. Both programmes measure the waist and read it with the blood, so the number comes with a meaning attached.
Sources
- International Diabetes Federation. The IDF consensus worldwide definition of the metabolic syndrome. Brussels: IDF, 2006
- WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. The Lancet, 2004;363(9403):157-163
- Katulanda P, Jayawardena MAR, Sheriff MHR, Constantine GR, Matthews DR. Prevalence of overweight and obesity in Sri Lankan adults. Obesity Reviews, 2010;11(11):751-756
- Katulanda P, Jayawardena MAR, Sheriff MHR, Matthews DR. Derivation of anthropometric cut-off levels to define CVD risk in Sri Lankan adults. British Journal of Nutrition, 2011;105(7):1084-1090
- National Institute for Health and Care Excellence (NICE). Overweight and obesity management. NICE guideline NG246, 2025. Section 1.9, Identifying and assessing overweight, obesity and central adiposity
- Ashwell M, Gunn P, Gibson S. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obesity Reviews, 2012;13(3):275-286
This article is general information, not individual medical advice. It does not replace assessment by your treating physician. If you have symptoms — chest pain, breathlessness or any urgent concern — seek medical attention immediately (Suwa Seriya 1990).