What is Body Mass Index (BMI)?
What is Body Mass Index (BMI)?
BMI is an acronym for Body Mass Index. Health organizations, doctors, dieticians, insurance companies, authors, fitness trainers, and many others use the BMI calculation to define a healthy weight range based on an individual's weight and height.
The BMI calculation
can be traced back to the early to mid 1850s. The Body Mass Index formula was
developed by a gentleman named Adolphe Quetelet, who was a mathematician / statistician guru. He developed this formula as a way to compare
people's body mass.
In the 1960s,
more than 100 years later, obesity became a topic of interest in the medical
community as well as within social interest groups. With the use of the computer and the ability to gather, compile,
and analyze data, the BMI (Body Mass Index) has become increasingly more popular
and more widely used. Over the last
150 years the formula and method of indexing has been refined and has evolved into
the BMI formula that we use today.
person's BMI is a popular way to determine obesity level and healthy weight
levels. It's a simple, quick and
inexpensive measurement. Today, just about all publicized statistics regarding
weight and obesity are derived from using the Body Mass Index (BMI). The CDC, National Institutes of Health,
World Health Organizations, and many others use BMI to determine healthy weight
What is the Purpose of a BMI Calculation?
The main purpose of
the BMI calculation is to provide a general assessment of a person's body
composition, primarily body fat. BMI is a more accurate way to measure obesity
than the traditional means of stepping on a scale. Measuring weight alone can
be misleading because it gives no indication of body fat composition.
The Body Mass Index assumes that a healthy person’s body, based on a certain height, should have a similar base weight, resulting from bones, tissues, organs, fluid, etc… So, ideally, people who are the same height should have a similar optimum weight range. Makes sense, doesn't it?
that BMI is only a "general" calculation because it is a quick
formula that uses only two fixed variables; weight and height.
How is BMI Calculated?
In simple terms, the BMI formula uses weight and height to determine your body mass composition.
Body Mass Index Formula:
(Weight / (height x height)) x 703 = BMI
Note: Your height needs to be measured in inches rather than feet.
Example: 5’11” male that weighs 180 lbs
(180 lbs/ (71 x 71)) * 703 = 25
Interpreting Your BMI Number:
Underweight = 18.5 and below
Normal Weight = 18.6 - 24.9
Overweight = 25 - 29.9
Obese = 30 +
Controversy Over Using BMI
The controversial problem with the BMI calculation is that it makes broad assumptions based on only two variables, weight
and height. Consider the following scenarios:
· I can be 5’11”, weigh 200 lbs, be at peek physical condition as a body builder, and have lean muscle tissue, but according to the BMI calculation, I would be considered obese.
· OR I can be 5’ 11” weigh 170 lbs, but be in lousy physical condition but still be considered a healthy weight according to my BMI.
· OR I could be a 5’ 11" and genetically have a larger frame, which means I don't fit the average BMI range for my height and weight.
As a result, this has lead to a lot of controversy over the use of BMI to assess a person’s (or group of people’s) physical condition, body composition, and most importantly their health.
Concluding Remarks on BMI
The bottom line
is, take it for what it's worth. BMI is
only one of many tools used for measuring healthy weight loss. Remember, your ultimate goal isn't what the scale shows, or what your body mass index is, but rather to build a healthier lifestyle.