Health & Screening
Body Mass Index (BMI)
Body Mass Index (BMI) is a simple weight-for-height measure used to screen adults for underweight, overweight and obesity.
What is BMI?
Body Mass Index (BMI) is a number calculated from a person's weight and height:
BMI = weight (kg) ÷ height (m)²
For example, a person who weighs 70 kg and is 1.70 m tall has a BMI of about 24.2 (70 ÷ 2.89).
BMI is widely used in health checkups and health risk assessments because it is quick, free and easy to track over time.
BMI ranges and the Indian context
The WHO's general classification for adults is:
| BMI | WHO classification |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Normal |
| 25.0 to 29.9 | Overweight |
| 30.0 and above | Obese |
Research has shown that many South Asian people, including Indians, can face higher risks of diabetes and heart disease at lower BMI levels than Europeans. For this reason, a WHO expert consultation on Asian populations and Indian consensus guidelines suggest lower action points, commonly treating a BMI of 23 or above as overweight and 25 or above as obese for Indian adults. Your doctor may use these Indian cut-offs.
Limitations
BMI is a screening tool, not a diagnosis. It does not distinguish fat from muscle, so very muscular people may show a high BMI, and it does not show where fat is stored. Fat around the waist is linked to higher cardiometabolic risk, which is why waist circumference is often measured alongside BMI. BMI also isn't designed for children or pregnancy in the same way. A doctor should interpret it together with other tests such as a lipid profile and HbA1c.
Why it matters for employers
BMI is an easy, low-cost starting point in workplace health checkups. Aggregated, anonymised BMI trends can help employers decide whether to invest in programs for nutrition, physical activity or weight management. It should always be handled sensitively: never used to judge or rank individuals, and kept confidential.
Example
At an onsite checkup camp, an employee learns his BMI is 24, which is in the normal range by WHO cut-offs but above the commonly used Indian action point of 23. The doctor also checks his waist measurement and blood tests, discusses his overall risk, and suggests small changes in diet and activity, with a recheck at his next annual checkup.
Key takeaways
- BMI = weight (kg) divided by height (m) squared.
- Indian adults are often assessed using lower cut-offs: 23 for overweight and 25 for obesity.
- BMI is a screening tool; interpret it with waist size and other tests.
- Support employees through weight management and chronic care programs.