What is BMI?

BMI stands for Body Mass Index and is a way to calculate body fat in adult men and women.  It’s a quick way to find out how healthy or unhealthy weight wise you are in comparison to your current weight and height.  Most BMI calculators will give you a number based on your current weight and height and with that number it will put you into 8 different categories.  These categories are listed below:

 

Very severely underweight –  If your BMI is less than 15.0 than you’ll fall into this category.

Severely underweight –  If your BMI ranges from 15.0 to 16.0 than you’ll fall into this category.

Underweight – BMI ranges for this category are 16.0 to 18.5

Normal – Ranges for this category are BMI’s of 18.5 to 25

Overweight – BMI range of 25 to 30

Obese Class 1 – If your BMI falls in between 30 and 35 then you’ll end up here.

Obese Class 2 – The BMI ranges are 35 to 40 for this unfortunate category

Obese Class 3 – Any BMI over 40 will put you here.

Disadvantages of using BMI

BMI is not the total answer to find out if you are currently healthy or unhealthy.  It does not take into account your muscle mass which can completely sway a number one way or another.  This is especially true in adult males and most body builders would end up in the obese categories when obviously they are not.  Also for girls if you have large breasts then this could also sway your number higher than normal even though you may not be unhealthy BMI does not take this into account. In addition to those 2 areas it also does not take into account of varying proportions of fat, bone, cartilage, water weight, ect. Also, BMI isn’t used for children and can only be used for adults.

The main reasons that BMI has several short comings is it only asks for 2 values, height and weight.  For instance, comparing BMI to Body Fat % calculations there are major differences.  In a 2008 study BMI defined 21% of the men and 31% of the women as being obese.  Using the same test subjects, body fat % found that 50% of the men and 62% of the women were considered obese.

These disadvantages all add up to only using BMI as one way to figure out your body fat.  Since it does not take into account your body frame size, be very cautious about getting a disappointing number as you may not be overweight at all.

Advantages of using BMI

Obviously the main advantage of using BMI is that it can be calculated quickly and without expensive equipment.  Also, BMI has been accepted by many clinical professions such as physicians and pharmacists.  Even though it may not truly accurate, it should still fall into a close area of where the individual is.  This is the main reason why insurance companies have adopted using BMI as a way to figure out if the individual is overweight or not and to decide to either raise, lower, or not insure the applicant.

BMI Calculator

If you want a BMI Calculator you can find one on our Pro Ana home page.   Again, have fun playing with it but remember that BMI number may be far off from the real result.