Body Mass Index
Everyone wants to know if they are healthy. They use their own measurements against standards set by the medical community. One of the most commonly used measurements is the Body Mass Index (BMI). BMI is calculated using height and weight and gives a number that places you in a preset group, from underweight to morbidly obese. BMI is easy and convenient to tell if you're normal, obese, or overweight, but there are limits to using just BMI to get to know about your health. People who train intensely or are actively involved in sports should consult a specialist if BMI puts them in 'unhealthy' group
If you think your BMI is high and you need a thorough and scientific plan to work on your weight, use our Weight loss calculator (for women | for men ).
The BMI is universally expressed in kg/m2, resulting from mass in kilograms and height in metres. If pounds and inches are used, a conversion factor of 703 (kg/m2)/(lb/in2) must be applied. In informal conversation units are usually omitted.
BMI gives a simple index number for a person's weight with respect to other people, allowing health professionals to discuss weight problems more objectively with their patients. BMI was designed to be used as a simple means of classifying average sedentary (physically inactive) populations, with an average body composition.
For such individuals, the value recommendations as of 2014 are as follows:
| From | To | Weight |
|---|---|---|
| 18.5 | Underweight | |
| 18.6 | 25 | Healthy |
| 26 | 30 | Overweight |
| 31 | 35 | Obese (I) |
| 36 | 40 | Obese (II) |
| 41 | Obese (III) |
Lean male athletes often have a high muscle-to-fat ratio and therefore a BMI that is misleadingly high relative to their body-fat percentage.
The BMI overestimates roughly 10% for a large (or tall) frame and underestimates roughly 10% for a smaller frame (short stature). In other words, persons with small frames would be carrying more fat than optimal, but their BMI indicates that they are normal. Conversely, large framed (or tall) individuals may be quite healthy, with a fairly low body fat percentage, but be classified as overweight by BMI.
A new formula for computing Body Mass Index that accounts for the distortions of the traditional BMI formula for shorter and taller individuals has been proposed by Nick Trefethen, Professor of numerical analysis at the University of Oxford:
