You check your BMI and it reads 24.2 — the WHO says that's normal. But your doctor is concerned. Why? Because research over the past two decades has consistently shown that South Asians — including Indians — have significantly higher body fat percentage and metabolic disease risk at the same BMI compared to Caucasians. The universal WHO cutoffs may be giving millions of Indians a false sense of security.
What is BMI and How is it Calculated?
Body Mass Index (BMI) = Weight in kg ÷ (Height in metres)². It was developed by Belgian mathematician Adolphe Quetelet in 1832 primarily using data from European men. Despite its limitations, it remains the most widely used screening tool for assessing body weight because it is simple, non-invasive, and free.
WHO Standard vs Indian-Specific Cutoffs
WHO standard: Underweight < 18.5 | Normal 18.5–24.9 | Overweight 25–29.9 | Obese ≥ 30. Indian/Asian-specific (recommended by ICMR and WHO expert committee): Underweight < 18.5 | Normal 18.5–22.9 | Overweight 23–24.9 | Obese ≥ 25.
This means a BMI of 23.5 — perfectly "normal" by WHO standards — is classified as "overweight" by Indian health guidelines, and may already warrant lifestyle interventions. This is not alarmism; it is based on robust epidemiological evidence.
Why Indians Have Higher Risk at Lower BMI
Multiple studies have shown that at the same BMI, South Asians have 3–5% higher body fat percentage than Caucasians. This "thin-fat" phenotype — where Indians appear lean but carry excess visceral (abdominal) fat — is particularly dangerous. Visceral fat is metabolically active and directly causes insulin resistance, type 2 diabetes, hypertension, and cardiovascular disease.
The Jaipur Heart Watch study found that Indians had significant cardiovascular risk factors at BMI values as low as 21–23. India currently has the second-largest population of diabetics globally (~101 million), and a significant proportion have a BMI below 25 — which would be classified as "healthy" by WHO standards.
Waist Circumference: A Better Indicator for Indians
For Indians, waist circumference is often a better predictor of metabolic risk than BMI alone. ICMR-recommended cutoffs: Abdominal obesity in men: ≥ 90 cm (compared to 102 cm in the Western standard). Abdominal obesity in women: ≥ 80 cm (compared to 88 cm in the Western standard). Measure at the midpoint between the lowest rib and the iliac crest (hip bone), while standing, after a normal exhale.
BMI Limitations to Keep in Mind
BMI does not distinguish between muscle and fat. A trained athlete with high muscle mass will have a high BMI but very low body fat — they are not at risk. Conversely, someone with low muscle mass and high fat (common in sedentary individuals) may have a "normal" BMI but a dangerous body composition. Use BMI as a first screening tool, not as a definitive health assessment.
What to Do If Your BMI is in the 23–25 Range
A BMI of 23–25 for an Indian is a signal to: 1) Measure your waist circumference. If above 90 cm (men) or 80 cm (women), prioritise abdominal fat reduction. 2) Check fasting blood glucose and HbA1c — Indians are prone to prediabetes even at normal weight. 3) Focus on diet quality — reduce refined carbohydrates (white rice, maida), increase protein and vegetables. 4) Add at least 150 minutes of moderate exercise per week. 5) Consult your doctor for a comprehensive metabolic panel.