What is Body Mass Index (BMI)?
Body Mass Index (BMI) is a widely used screening method that categorizes a person's weight status. By calculating the ratio of your weight to your height, BMI provides a simple numeric value that helps healthcare professionals and individuals assess potential health risks associated with body weight.
While BMI is not a direct measure of body fat, it correlates moderately with more direct measures. It is an essential starting point for weight management and acts as a general health tracker for adults.
How is BMI Calculated?
Metric Formula
BMI = kg / m²
Weight in kilograms divided by height in meters squared.
Imperial Formula
BMI = 703 × lbs / in²
Weight in pounds divided by height in inches squared, multiplied by 703.
Understanding BMI Categories
| Category | BMI Range |
|---|---|
| Underweight | < 18.5 |
| Normal Weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obese | 30 or greater |
Limitations
- Athletes: High muscle mass can result in a high BMI, misclassifying fit individuals.
- Age: Elderly individuals often lose muscle, so a "normal" BMI might mask fat.
- Pregnancy: Not applicable for pregnant women.
Healthy Tips
- Eat fruits, vegetables, & whole grains.
- 150 mins moderate activity/week.
- Sleep 7-9 hours per night.
Frequently Asked Questions
When is the best time to weigh myself?
In the morning, after using the restroom and before eating. This provides the most consistent baseline.
Does BMI calculation differ for men and women?
The formula is the same. However, interpretations may vary slightly as women naturally have higher body fat percentages.
Why is my BMI High but I am not fat?
If you are muscular, your BMI might indicate 'overweight' due to muscle density. In this case, body fat percentage is a better metric.