Body Mass Index

I keep hearing this term often when it comes to fitness. I have tried reading something on the websites to know what it is.

Either I happened to read complicated definitions or it was too much for me to understand :?

Can anyone give me a simple explanation of it? Thks.

Nila,

BMI is a new term for most people. BMI equals a person's weight in kilogram divided by height in meters squared ie Kg/m2

Doctors are indicating that weight alone can't be a determinant of whether a person is over weight or not. Weight, together with height, is a better indicator of an individual weight status. That is why BMI is helpful as it takes into account both weight and height.

Hope this helps.

Reshna, that is exactly my understanding as well.

Nila, here is a rough guide on what BMI equals in terms of weight status..

BMI	Weight Status
Below 18.5	Underweight
18.5 – 24.9	Normal
25.0 – 29.9	Overweight
30.0 and Above	Obese

I am in the upper end of Normal

As I mentioned in my earlier message,

xxxxxxxxxxxWeight in Kilograms
BMI = ------------------------------
xxxxxxHeight in Metres x Height in Metres

To use the above formula, we need weight in kilograms and height in metres. In India, we are used to measuring weight in kilograms. So, no issues there. However, we measure height in feet and inches, not metres. To convert height into metres, here is a quick way.

First convert height into inches. 1 Feet = 12 inches. So, if your height is 5ft and 10 inches, then it is 5x12 + 10 = 70 inches. Second, convert inches into metres. 1 inch = 0.0254 metres. So, 70 inches is 70 x 0.0254 = 1.778 metres.

Now, you are ready to use the formula to calculate BMI. Assume an individual who weights 80 Kilograms.

xxxxxxxxxx80
BMI= -------------- = 25.3
xxxxxx1.778 x 1.778

As per the table given by Ankita, the above individual is over weight!

Hi Reshna,

Thanks for that detailed explanation. In the US, they measure weight in pounds and height in inches. Any easy formula that you can provide us for measuring BMI in such a situation?

Bharthi - Happy to help.

In such a situation, the formula slightly changes as follows...

xxxxxxxxxxxWeight in Pounds
BMI = ------------------------------ x 703
xxxxxxHeight in Inches x Height in Inches

If you are 150 Pounds and 70 inches, your BMI is

xxxxxxx150
BMI = -------- x 703 = 21.52
xxxxxx70 x 70

As per the table given by Ankita, the above individual is normal weight!

Dear Friends,
thanks for providing the BMI formula so clearly. I applied my statistics to the formula and got an answer of 24.66. (187 pounds and 6' 1") I have heard people saying that I am slightly overweight. Now I can throw the figures before them to say I am normal or as Ankita fashionably said "in the upper end of normal" ha ha!
You made my day, ladies.
varalotti

Dear all:

Currently, Body Mass Index (BMI) is arrived as a ratio between height and weight of an individual. According to a study published in "The Lancet" the ratio between the belly size and hip size appears to be a more useful index of health risk than the widely used BMI. The deficiency with the currently used BMI is that it does not take into account where the weight is carried in the body.

Measuring the girth of the waist and hip is of far more utility.

To calculate the waist-to-hip ratio (WHR), measure your waist (in inches) at the smallest part, then measure your hip at the widest; divide your waist measurement by your hip measurement.

WHR less than 0.8 and 1.0 for women and men respectively, is the lowest risk.