Top 10 Reasons Why The BMI Is Bogus

1. The person who dreamed up the BMI said explicitly that it could not and should not be used to indicate the level of fatness in an individual.

The BMI was introduced in the early 19th century by a Belgian named Lambert Adolphe Jacques Quetelet. He was a mathematician, not a physician. He produced the formula to give a quick and easy way to measure the degree of obesity of the general population to assist the government in allocating resources. In other words, it is a 200-year-old hack.

2. It is scientifically nonsensical.

There is no physiological reason to square a person's height (Quetelet had to square the height to get a formula that matched the overall data. If you can't fix the data, rig the formula!). Moreover, it ignores waist size, which is a clear indicator of obesity level.

3. It is physiologically wrong.

It makes no allowance for the relative proportions of bone, muscle and fat in the body. But bone is denser than muscle and twice as dense as fat, so a person with strong bones, good muscle tone and low fat will have a high BMI. Thus, athletes and fit, health-conscious movie stars who work out a lot tend to find themselves classified as overweight or even obese.

4. It gets the logic wrong.

The CDC says on its Web site that "the BMI is a reliable indicator of body fatness for people." This is a fundamental error of logic. For example, if I tell you my birthday present is a bicycle, you can conclude that my present has wheels. That's correct logic. But it does not work the other way round. If I tell you my birthday present has wheels, you cannot conclude I got a bicycle. I could have received a car. Because of how Quetelet came up with it, if a person is fat or obese, he or she will have a high BMI. But as with my birthday present, it doesn't work the other way round. A high BMI does not mean an individual is even overweight, let alone obese. It could mean the person is fit and healthy, with very little fat.

5. It's bad statistics.

Because the majority of people today (and in Quetelet's time) lead fairly sedentary lives and are not particularly active, the formula tacitly assumes low muscle mass and high relative fat content. It applies moderately well when applied to such people because it was formulated by focusing on them. But it gives exactly the wrong answer for a large and significant section of the population, namely the lean, fit and healthy. Quetelet is also the person who came up with the idea of "the average man." That's a useful concept, but if you try to apply it to any one person, you come up with the absurdity of a person with 2.4 children. Averages measure entire populations and often don't apply to individuals.

6. It is lying by scientific authority.

Because the BMI is a single number between 1 and 100 (like a percentage) that comes from a mathematical formula, it carries an air of scientific authority. But it is mathematical snake oil.

7. It suggests there are distinct categories of underweight, ideal, overweight and obese, with sharp boundaries that hinge on a decimal place.

That's total nonsense.

8. It makes the more cynical members of society suspect that the medical insurance industry lobbies for the continued use of the BMI to keep their profits high.

Insurance companies sometimes charge higher premiums for people with a high BMI. Among such people are all those fit individuals with good bone and muscle and little fat, who will live long, healthy lives during which they will have to pay those greater premiums.

9. Continued reliance on the BMI means doctors don't feel the need to use one of the more scientifically sound methods that are available to measure obesity levels.

Those alternatives cost a little bit more, but they give far more reliable results.

10. It embarrasses the U.S.

It is embarrassing for one of the most scientifically, technologically and medicinally advanced nations in the world to base advice on how to prevent one of the leading causes of poor health and premature death (obesity) on a 200-year-old numerical hack developed by a mathematician who was not even an expert in what little was known about the human body back then.

BMI of CelebsAnd Athletes

Angelina JolieEstimated BMI: 17.9

The mother of six must stay lean chasing after her

growing brood: At 5'8", our experts say she probably

weighs about 118 lbs. Though many people envy

her beauty and accomplishments, her estimated BMI of 17.9

suggests she'd be an even better role model if she

gained some weight.

BeyonceEstimated BMI: 21

This "Bootylicious" songstress gets called curvy by the tabloids, but by

BMI standards, she's perfectly proportioned. Our experts

estimate that Beyonce is a svelte 130 lbs. At 5'6", that gives her an estimated BMI of 21—well within

the "normal" range.

So if Beyonce's BMI is right on target, what about all the super-

skinny celebs that make her seem shapely?

Tom CruiseEstimated BMI: 26

He may not be scaling mountains in his movies

anymore, but there's nothing wrong with Cruise's current

physique—or is there?The 5'7" star clocks in at an estimated 166 lbs. With a

corresponding BMI of 26, he'd be considered "overweight."

Tony RomoEstimated BMI: 28.8

Whatever you think about his performance on the field, it's hard to deny that Romo's body is pretty

perfect. But if you go by BMI standards, the Dallas Cowboys

quarterback is "significantly overweight." He's listed at 6'2"

and 224 lbs., giving him a BMI of 28.8.

"A better measurement of an athlete’s body composition

includes a comparison of lean body mass to body fat," says

Largeman-Roth.

Serena WilliamsEstimated BMI: 22.1

Not all athletes seem to totter on the edge of obesity. This

super-fit tennis sensation has a BMI of 22.1, which is well within the normal range.

At 5'9", her competition weight has recently been just 150 lbs., meaning she packs on a whole

lot of muscle and practically zero fat.

Arnold SchwarzeneggerEstimated BMI: 30.8

This former bodybuilder and Terminator star is the poster child for physical

fitness. But surprise! He's "obese"—at least according to his BMI. He stands tall at

6'2" and our experts say Schwarzenegger probably

weighs in at about 240 lbs., which would give him a super-high BMI of 30.8.

Dwight HowardBMI: 27

(Overweight)

Height: 6'11" Weight: 265 lbs.

Blake GriffinBMI: 26.3

(Overweight)

Height: 6'10" Weight: 251 lbs.

Chris PaulBMI: 25.7

(Overweight)

Height: 6'0“Weight: 190 lbs

LeBron JamesBMI: 27.4

(Overweight)

Height: 6'8“Weight: 249 lbs.