The BMI is used to classify the degree by which a person departs from the “ideal” weight for a person’s height. Many people today, including physicians, use BMI as an indicator of health or for medical diagnosis, particualrly because it is an extremely easy calculation.
BMI is calculated as follows:
BMI = weight in pounds/(height in inches x height in inches) x 703
The result is often grouped into the following classifications:
|Less than 15||Starvation|
|15 to 18.49||Underweight|
|18.5 to 25||Ideal|
|25.01 to 30||Overweight|
|30.01 to 40||Obese|
|Greater than 40||Morbidly Obese|
The BMI has come under fire recently on several fronts. In particular, a recent study found that people with a higher BMI actually live longer. Another recent study also found that overweight (as classified by the BMI) young women may have a reduced risk of developing breast cancer.
Additionally, BMI makes no distinction between body weight from muscle and body weight from fat. Listed below are many famous individuals who are either classified as obese or overweight. Obviously, they are neither.
|Tom Brady||6’4″||225 lbs||27|
|Kobe Bryant||6’6″||200 lbs||25|
|George Clooney||5’11″||211 lbs||29|
|Matt Damon||5’11″||187 lbs||26|
|Johnny Depp||5’7″||190 lbs||27|
|Vin Diesel||6’2″||200 lbs||26|
|Lebron James||6’8″||240 lbs||26|
|Michael Jordan||6’6″||216 lbs||25|
|Nick Lachey||5’10″||180 lbs||26|
|Yao Ming||7’6″||310 lbs||27|
|Brad Pitt||6’0″||203 lbs||28|
|Keanu Reeves||6’1″||223 lbs||29|
|Andy Roddick||6’2″||197 lbs||25|
|Nykesha Sales||6’0″||184 lbs||25|
|Will Smith||6’2″||210 lbs||27|
|Denzel Washington||6’0″||199 lbs||27|
|Tom Cruise||5’7″||201 lbs||31|
|Steve McNair||6’2″||235 lbs||30|
|The Rock (Dwayne Johnson)||6’5″||275 lbs||33|
There is a push for using waist circumference as a better indicator of health.
From a fat loss perspective, BMI can be flawed, especially if you are begining a weight training program. As you put on muscle, your BMI may stay the same, or increase slightly – indicating no progress. As evidenced by the list of athletes and thespians above, you can lose a great deal of fat, and still be classified as overweight or obese.
I personally use waist circumference and several “hand” calculations/estimations of body fat % (which takes into account both weight and waist size, among other factors) to monitor my progress. I find these to be more “directionally” correct, and a better measure of my overall appearance.