BMI (Body Mass Index) is calculated by dividing weight (kg) by height (m) squared. It's the most widely used indicator of body fatness, developed by Belgian mathematician Adolphe Quetelet in the 19th century.
WHO classification:
🔵 Underweight: BMI < 18.5
🟢 Normal: BMI 18.5 – 24.9
🟡 Overweight: BMI 25 – 29.9
🔴 Obese: BMI ≥ 30
Asian/Chinese standards differ slightly: overweight starts at 24, obesity at 28. Asian populations face metabolic risks at lower BMIs.
BMI can't distinguish muscle from fat. A muscular athlete may have an overweight BMI but be perfectly healthy. Conversely, a normal-BMI person may carry excess visceral fat ("skinny fat").
Combine these metrics for a fuller picture:
📏 Waist circumference: ≥ 90cm (men) / ≥ 85cm (women) indicates abdominal obesity
📐 Waist-to-hip ratio: > 0.9 (men) / > 0.85 (women) is risky
📊 Body fat percentage: 15-20% (men) / 20-25% (women) is healthy
🩸 Metabolic markers: Blood sugar, lipids, and blood pressure are the ultimate health indicators
Q: Is normal BMI always healthy?
A: Not necessarily. A normal-BMI person with a large waist or high body fat still faces elevated cardiovascular risk. Combine BMI with waist circumference and body fat measurements.
Q: What BMI is ideal?
A: A BMI of 20-25 is associated with the lowest mortality risk. But individual variation is significant — don't obsess over a specific number.