What is BMI?
Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in metres squared.
BMI is a useful measure of overweight and obesity. It is calculated from your height and weight. BMI is an estimate of body fat and a good gauge of your risk for diseases that can occur with more body fat.
How is BMI Calculated?
The BMI formula is straightforward:
- Metric: BMI = weight (kg) / height² (m²)
- Imperial: BMI = 703 × weight (lbs) / height² (in²)
BMI Categories
According to the World Health Organization (WHO):
- Underweight: BMI less than 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25 to 29.9
- Obesity: BMI 30 or greater
Limitations of BMI
While BMI is a useful screening tool, it has limitations:
- It doesn't distinguish between muscle and fat
- It doesn't account for age, sex, or ethnicity
- Athletes may have high BMI due to muscle mass
- Elderly people may have normal BMI but high body fat
Why BMI Matters
Despite its limitations, BMI remains valuable because:
- It's easy to calculate
- It correlates with body fat
- It predicts health risks
- It's useful for population studies
Tips for Maintaining Healthy BMI
- Balanced Diet: Focus on whole foods, vegetables, and lean proteins
- Regular Exercise: Aim for 150 minutes of moderate activity weekly
- Stay Hydrated: Drink plenty of water throughout the day
- Get Enough Sleep: Poor sleep can affect weight management
- Manage Stress: Chronic stress can lead to weight gain



