BMI is one of those health metrics that everyone has heard of and almost nobody fully understands. Your doctor mentions it during annual checkups, fitness apps calculate it automatically, and insurance companies use it to assess risk. But there's a specific problem with BMI for Indians that most people — including many doctors — don't talk about enough.
How BMI is calculated
The formula is simple: weight in kilograms divided by height in metres squared. So if you weigh 72 kg and are 1.70 m tall, your BMI is 72 ÷ (1.70 × 1.70) = 24.9.
Standard WHO categories put 18.5–24.9 as normal, 25–29.9 as overweight, and 30+ as obese. You've seen these charts. Here's what most of them don't mention — these thresholds were developed primarily using data from Western, European-origin populations. And they don't translate well to Indians.
Why Indians face higher risk at lower BMI
Multiple large studies — including ICMR research published in peer-reviewed journals — have found that South Asians develop Type 2 diabetes, hypertension, and cardiovascular disease at significantly lower BMI values than people of European origin.
The reason is body composition. At the same BMI, Indians tend to carry more visceral fat — the fat that wraps around internal organs like the liver, kidneys and pancreas. This type of fat is metabolically far more dangerous than the subcutaneous fat you can pinch under your skin. A person of European origin with a BMI of 27 might have a relatively healthy metabolic profile. An Indian person with the same BMI may already have insulin resistance.
This is why the WHO Asia-Pacific guidelines recommend different cutoffs for South Asians. For Indians, overweight starts at BMI 23 (not 25), and high risk starts at 27.5 (not 30). If your BMI is 24 and you're Indian, you're not "normal weight" by Indian-appropriate standards — you're in the overweight category with elevated metabolic risk.
What BMI can't tell you
BMI doesn't distinguish between muscle and fat. A well-built person who lifts weights regularly will have a higher BMI than their lean, sedentary colleague — but they're obviously healthier. BMI also doesn't tell you where your fat is distributed, which matters enormously.
Two people with identical BMIs can have wildly different health risks depending on whether they carry fat around the belly or around the hips and thighs. Belly fat (abdominal obesity) is the dangerous kind — it's associated with heart disease, diabetes, and liver disease. Hip and thigh fat is relatively harmless.
Better ways to assess your health
Waist circumference is more predictive of metabolic disease than BMI for Indians. The risk thresholds for Indians are 90 cm for men and 80 cm for women. If you're above these numbers, that's more meaningful than what your BMI says.
Waist-to-height ratio is even better. Divide your waist by your height — both in the same unit. If the result is above 0.5, you have excess abdominal fat regardless of what your BMI shows. This is called "central obesity" and it's the real risk factor that gets underdiagnosed in India because people look at BMI and think they're fine.
Fasting blood glucose is the most direct measure of metabolic health. If you're above 100 mg/dL, you're in pre-diabetic range. Get this tested once a year if you're over 30, especially if diabetes runs in your family.
What I think is more useful than obsessing over BMI
Honestly — focus on waist circumference and annual blood work over your BMI number. A 30-minute brisk walk five days a week, reducing white rice and maida intake, and keeping your waist under the threshold will do more for your long-term health than hitting a specific BMI target.
BMI is a useful screening tool, not a diagnosis. Use it as a starting point, not the final word on your health.
Calculate your BMI with Indian-specific risk assessment using our BMI Calculator.