Healthy BMI for South Asians: why the line sits at 23, not 25.

Why is a healthy BMI different for South Asians?

Because the same BMI doesn't carry the same risk for everyone. A large UK study shows that people of South Asian background, including Pakistanis, develop type 2 diabetes at a lower BMI than white Europeans, so the usual cut-offs of 25 and 30 can miss risk that's already there.

BMI (body mass index) is your weight in kilograms divided by your height in metres, squared. It uses only two numbers, so it can't tell muscle from fat, and it can't show where your fat sits. A man with a round belly and thin arms can have the same BMI as a man who lifts weights at the gym.

That doesn't make BMI useless. It's free and takes a minute, so it's a fair first check. For Pakistanis it works better with two additions: the lower South Asian cut-offs, and a tape measure around your waist.

What did the Warwick study of 1.5 million people find?

It found that the type 2 diabetes risk white people had at a BMI of 30 was reached by South Asians at a BMI of 23.9. The University of Warwick study looked at 1.5 million people in England and was published in The Lancet Diabetes & Endocrinology in 2021.

Put that into kilos and the gap is large. For a woman who is 5 feet 3 inches (160 cm) tall, a BMI of 23.9 is about 61 kg and a BMI of 30 is about 77 kg. The same level of risk shows up at a weight about 16 kg lower.

The study was done in England, and it looked at ethnic background rather than country. UK guidance now uses lower cut-offs based on family background, not on where you live. For a Pakistani in Multan or in Manchester, the lower lines are the safer ones to use.

What is the Asian BMI chart?

It's the set of lower BMI cut-offs used for people of Asian family background. NICE guideline NG246 treats a BMI of 23 to 27.4 as overweight and 27.5 or above as obesity for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background.

If you'd rather skip the maths, find your height below. The first column of weights is where overweight begins on the South Asian chart, and the second is where obesity begins.

Lower isn't always better. A very low weight brings its own problems, so if you're losing weight without trying, see your doctor.

How do you measure your waist at home?

Use a soft tape halfway between your lowest rib and the top of your hip bone, breathe out normally, then divide your waist by your height. NICE suggests keeping your waist to less than half your height.

1. Stand up straight, with the tape on your skin or over a thin vest, not over a thick kameez.
2. Find the bottom of your ribs and the top of your hip bone on one side. Wrap the tape around your middle halfway between the two.
3. Keep the tape flat and snug without pulling it in. Breathe out gently and read it.
4. Use the same units for both numbers: centimetres with centimetres, or inches with inches.

This spot is often higher than where your shalwar or trousers sit, so your trouser size isn't a good guide.

These ranges are for adults with a BMI under 35, and NICE uses them for every ethnic group.

Why does age 25 matter for Pakistanis?

Because the risk of type 2 diabetes starts earlier for South Asians. Diabetes UK says that for people of South Asian background, including Pakistanis, risk rises from age 25, compared with 40 for white Europeans.

In Pakistan, diabetes is common. The IDF Diabetes Atlas puts the age-standardised rate of diabetes among adults aged 20 to 79 at 31.4%, the highest in the world, and estimates that 26.9% of adults with diabetes haven't been diagnosed. A blood test is how you find out.

So if you're over 25 and your BMI or waist is in the higher range, ask your doctor about an HbA1c or fasting glucose test. The American Diabetes Association counts an HbA1c of 5.7 to 6.4% as prediabetes and 6.5% or higher as diabetes, and a diagnosis usually needs two abnormal results. Our guide to insulin resistance and Pakistani food explains the tests and the possible early signs.

What should you do if your BMI or waist is in the higher range?

Treat it as useful information, not a verdict. Start with a check-up, then make small changes to the food you already eat. You don't need to reach a perfect number to lower your risk.

In a large US trial of 3,234 adults with raised blood sugar, a lifestyle programme aiming for at least 7% weight loss and at least 150 minutes a week of activity such as brisk walking cut the risk of developing type 2 diabetes by 58% compared with placebo (New England Journal of Medicine, 2002). For someone who weighs 75 kg, 7% is about 5 kg.

• Measure the fat. A tablespoon of ghee or oil is roughly 120 calories. Cooking the salan with a measuring spoon instead of pouring from the bottle is an easy place to start.
• Keep roti, watch the size. A roti made from 40 g of atta is about 135 calories before any ghee, and one from 30 g is about 100. Our article on roti and weight loss shows how to check yours.
• Protein and sabzi first. Build the plate around daal, chana, anda, chicken or fish with a full serving of sabzi, then add a smaller helping of rice or roti.
• Drink less sugar. Cut the sugar in your doodh patti a little at a time, and save sweet lassi, sharbat and cold drinks for occasions.
• Walk. 150 minutes a week is about 20 minutes a day, after dinner or around the mall when it's too hot outside.

Our Pakistani diet plan for weight loss has a sample week of home meals. If you live in the UK, Canada, the US or the Gulf, the guide to Pakistani food abroad covers takeaways and weekend dawats.

Every NutriZaika plan includes a Body Snapshot that checks your weight, waist and body-fat estimate against South Asian healthy ranges, and our cardiometabolic health service looks at blood sugar and cholesterol alongside weight. If you'd like a plan built around your own kitchen, see plans and pricing or book a consultation.