BMI or Body Mass Index is a globally acknowledged, scientific method of measuring obesity. Recommended by the WHO (World Health Organization), it is a simple index of weight- for- height, which is used to classify underweight, normal, overweight and obese adults along with their level of associated health risks. It is calculated by dividing the weight in kilograms by the square of an individual’s height in meters. The classification of Underweight, Normal Overweight and Obese according to BMI is given in the table below
Though globally a BMI of 25 is accepted as normal, for Asian Indians this value is considered higher because at lower BMI they tend to accumulate higher fat percentage which is the actual cause behind developing various other medical disorders and diseases.
A normal BMI should ideally fall between 18.5 and 22.9. A BMI between 23 and 29.9 is considered overweight and anything above that qualifies as obese.
Classification | Popular Description | BMI (kg/m2) | Risk of co-morbidities |
---|---|---|---|
Underweight | Thin  | <18.5 | Low (but risk of other clinical problems increased) |
Normal range | Normal | 18.5 - 22.9 | Average |
Overweight | 23 – 24.9 | ||
Pre-obese | Overweight | 25 - 29.9 | Increased |
Obese Class I | Obese | 30.0 - 34.9 | Moderate |
Obese Class II | Obese | 35.0 - 39.9 | Severe |
Obese Class III | Morbidly Obese | > = 40.0 | Very severe |