All You Need to Know About BMI


Senior Member
7 Jun 2011
Your BMI and You
One device that many people and doctors use to track fluctuations in body weight and their relationship to overall health is the Body Mass Index or BMI. The BMI is a single number that is said to evaluate a person's weight status relative to their height.

The simple formula for BMI is (weight [lbs] x 703) / (height squared [in inches squared]). This formula doesn't take into account differences in weight/density between bone, muscle, fat, organs, or water stored in the body. It's just a big simple number that tried to boil down an extremely complicated issue into something easy to understand. Unfortunately it's not that simple. The BMI is NOT a diagnostic tool. It can be used as a guideline to track weight issues, but that is all.

The Guide to BMI
According to "accepted" guidelines, there are different ranges indicating health, overweight, and obese. "Healthy" individuals are said to reside within the 18.5 to 24.9 range. People with BMIs greater than 25 but less than 30 are labeled overweight. Anything over 30 is obese.

The History of the Body Mass Index
The BMI has a long and colorful history of scientists and doctors trying to unravel the secret relationships between weight and health and diet and exercise and everything else that makes humans tick. It kind of makes you wonder how humans ever got along before modern medical science came along to tell them what was wrong with them and what they were doing.

The story of the BMI starts in 1832 when Adolphe Quetelet started work on the "Quetelet Index." Quetelet was searching for the medically/scientifically "normal" human. Presumably it was important to discern a baseline for a standard human so that abnormalities could be noted and medical/scientific research conducted.
The early 20th century saw the rise of insurance companies lead to the first ever large-scale study of health as pertains to obesity and weight. Apparently, when money starts to enter into the picture, everyone starts wanting to know more about what makes people sick, fat, and dead. Insurance companies wanted to know and show the relationship between overweight people and early death (presumably so that they could start charging more money).
The early 1900's went on to reveal many other maladies associated with being overweight and obese. Among these were (and still are) diabetes, hypertension, and heart disease. Many of these have been linked to excess adipose tissue.

Jumping forward to 1972 we see Ancel Keys (father of the "Lipid Hypothesis") publishing his "Indices of Relative Weight and Obesity." This tome purports to examine various height vs. weight indices in order to ascertain which formula did, indeed, reveal the most telling relationship between height, weight, obesity, and god health. Keys puts forward the "Quetelet Index" as the best possible match, thereby signifying that medical science had advanced not at all in 140 years.

In the 1980s the BMI becomes the international standard by which obesity and height/weight issues are compared and judged. The 1990s has the government launching healthy eating and exercising programs. This is when the BMI first becomes widely known.

Again: High BMI numbers are often found to be connected with various health risks. Cardiovascular diseases, hyperlipidemia, elevated insulin levels (often a precursor to diabetes), and increased blood pressure.

Population Numbers
Now that the BMI has become the yard stick by which all countries and peoples are judged for their height/weight health, it's worth seeing how the US stacks up against the rest of the world. For starters, America is the WORLD LEADER in OBESITY! An immense 30.6% of the population weigh in at more than 30 on the BMI scale. Mexico is fast behind them with 24.2% of people being obese.

No other countries on our list come anywhere near those numbers. Norway is down around 8.3% and Switzerland is even lower than that at 7.7%. Korea and Japan both has 3.2% obesity, which is not much at all.

In fact the distribution numbers of "overweight" and "obese" for adults are pretty chilling. Nearly two thirds of adults are overweight, while one third of adults are obese - which means that in the US, pretty much everyone over 18 is fat.

It's not just adults either - more and more children are being recorded as overweight and obese. Ten percent of children age 2 to 5 are obese. That number doubles in the 6 to 11 age range, with 20% being obese. It more or less holds steady into young adulthood, however, with only 18% of adolescents (ages 12 to 19) being obese.

Taking Control
A number of different factors influence BMI. Heredity and genetics can make you taller or shorter or more likely to store fat or burn it up as fuel. However, the food that you eat plays a major role in your BMI. The types of foods you eat and the affect that they have on insulin levels, etc. can also cause you to store food as fat.
However, buying higher quality foods and supplements can help you manage your BMI and keep your weight within healthy levels. Exercise and activity levels can also influence BMI and have beneficial affects on insulin sensitivity and blood pressure.


3 Feb 2013
I know about BMI. But i think you missed out something. There are easy ways to measure BMI for both men and women.

For more info,please visit couple of video tutorial of Edward checo.