Body Mass Index (BMI)

Body Mass Index (BMI) is a numerical value calculated by dividing a person's weight in kilograms by the square of their height in meters (kg/m²). Developed by Adolphe Quetelet in the 1830s and popularized as a clinical screening tool in the 1970s, BMI is used by healthcare providers worldwide to classify weight status. The WHO categories are: Underweight (BMI < 18.5), Normal (18.5–24.9), Overweight (25.0–29.9), and Obese (≥ 30.0). BMI is a population-level screening tool, not a direct measure of body fat, and has documented limitations for athletic populations and certain ethnicities.