Plug your height and weight into a generic online BMI calculator and it might tell you you're in the "Normal" range — while your doctor, using Indian clinical guidelines, tells you that you're overweight. Both are reading the same number correctly. They're just using different cutoffs, and the difference isn't a rounding error — it changes which category millions of people fall into.
Why the cutoffs are different at all
The original WHO BMI categories (overweight ≥25, obese ≥30) were developed mainly from studies on European/Caucasian populations. Research since then — including large studies specifically on Asian Indian populations — found that Indians tend to develop diabetes, high blood pressure, and heart disease risk at a lower BMI than the original cutoffs assumed, largely because Indian bodies tend to carry more visceral (internal, around-the-organs) fat at the same BMI compared to Caucasian bodies. In 2009, a consensus group of over 100 Indian medical experts formally proposed lower cutoffs specifically for this population.
| Category | Standard WHO cutoff | Asian Indian consensus cutoff |
|---|---|---|
| Underweight | < 18.5 | < 18.5 (same) |
| Normal | 18.5 – 24.9 | 18.5 – 22.9 |
| Overweight | 25.0 – 29.9 | 23.0 – 24.9 |
| Obese | ≥ 30.0 | ≥ 25.0 |
What this actually means for a real number
Someone with a BMI of 24 falls in the "Normal" range under the standard WHO scale — but is already classified as overweight under the Indian consensus guidelines. That's not a small gap: it's the difference between a calculator telling you everything is fine and a guideline suggesting it's worth paying attention to diet and activity levels now, before numbers climb further.
Where BMI falls short even with the right cutoff
BMI only uses height and weight — it can't tell the difference between muscle and fat. A muscular person can show a high BMI without carrying excess fat, while someone with a "normal" BMI can still carry unhealthy levels of visceral fat, especially around the waist. That's why waist circumference is often used alongside BMI in Indian clinical guidelines — commonly cited cutoffs for increased health risk are a waist above roughly 90 cm for men and 80 cm for women, though your doctor is the right person to interpret this alongside your BMI, not a calculator alone.
FAQs
Should I always use the Asian Indian cutoff instead of the
standard one?
If you're of South Asian descent, the Indian consensus cutoffs are
generally considered more clinically relevant for assessing
metabolic risk than the original WHO scale — but this is a
population-level guideline, not an individual diagnosis.
Does this mean the standard BMI calculator is "wrong"?
Not wrong — just calibrated for a different population. The
number itself (weight ÷ height²) is identical either way; only the
category labels attached to that number differ.
