Crab this BMI widget here
ON OUR NETCAST, PID Radio, Derek and I refer to repeating themes and ‘memes’ in current entertainment. The picture isn’t complete, however, without noting ‘non-fiction’ sources such as cable news and public policy announcements. Just this afternoon, an interesting ‘press release’ arrived in my mailbox from our friends at the Centers for Disease Control (CDC).
The title of the linked article is “Obesity Among U.S. Adults Continues to Rise”, continuing a healthcare drumbeat that underscores and supports President Obama’s call for a national healthcare bill. Americans, it seems, just can’t stay healthy on our own. We require guidance–and rules. Here’s an excerpt:
More than 400,000 U.S. adults were surveyed in the 2008 BRFSS [Behavioral Risk Factor Surveillance System], which is the world’s largest telephone health survey. To assess obesity prevalence, survey respondents are asked to provide their height and weight, which is used to calculate their body mass index (BMI). A person is considered obese if they have a BMI of 30 or above.
First of all, this ‘surveillance system’ assumes respondents reply honestly and accurately. For instance, if I asked for your weight and height, would you know the true numbers? My weight, for instance, fluctuates by as much as fifteen pounds on any given day, depending on how much fluid I retain. If I’m giving you that morning’s number, it could be which could be enough to put me over the line. Also, my height can vary depending on the time of day. If measured early in the morning, I tend to be more energetic, which can stretch my height to 5’5″. However, I’ve noticed if I go into the doctor’s office in the afternoon, my height might be as short as 5’4″ (this number can also vary according to the person with the measuring stick!). So, getting an accurate set of numbers is tricky–and that assumes I’d be honest with the caller. How many of us tell a perfect stranger the real numbers, eh? Next, you’ll expect me to wear my clothing labels on the outside!
But I digress. Back to the call from the BRFSS (not your BFF). Recording my weight and height may tell you a little about me, but it won’t tell you the composition of that weight. I might be excessively muscular (no, I’m not, but I COULD be–ok, so that’s a pipe dream–roll with me here).
BMI (Body Mass Index) is computed this way: Body weight divided by your height squared. The universal formula is: kg/m2. This cute little formula is the invention of a mathematician not a doctor. This quick ‘trick’ of numbers fails to consider waist size, bone density (the more fit, the denser the bones as a rule), muscle mass, or age.
What BMI does do is provide a neat and elegant means for classifying a huge majority of people as unhealthy. Any BMI over 25 falls into the overweight range! Thus, most athletes and many otherwise healthy individuals will falsely be labeled ‘unhealthy’ by number crunchers, and the new Obama Health Czars.
When I was in my twenties, I was mostly flab but very skinny. I rarely walked or worked out, but I starved myself to be thin. My BMI at that time would have been superb. As I aged, that flab turned to fat. However, while attending school at IU, I began to walk daily and work out weekly, and I ate healthy foods and seldom snacked. Before long, my weight hardly dropped, but my hips and waist grew smaller by the week. Within six months, I could wear my best friend’s size ten dresses, but I weighed 175 pounds. At 5″5′, that put my BMI at 29.1 — nearly into the morbidly obese range! You should have seen the muscles on my calves then! My waist was 27 inches!
BMI is a false and intentionally misleading number. But don’t take my word for it. Here’s a link to an article at the Mathematical Association of America’s website. Read what a numbers guy thinks of the government’s numerical sledgehammer.
Keith Devlin, the article’s author has this to say (and much more):
Why do we have this annual BMI charade? Why would otherwise well-educated medical professionals ignore the evidence of their own eyes? Because the BMI is one of those all-powerful magic entities: a number. And not just any number, but one that is generated by a mathematical formula. So it has to be taken seriously, right?
Sadly, despite that fact that completion of a calculus course is a necessary prerequisite for entry into medical school, the medical profession often seems no less susceptible than the general population to a misplaced faith in anything that looks mathematical, and at times displays unbelievable naivety when it comes to numbers.
BMI ranking is a numbers game, and it’s rigged to make Americans think we’re fatter than we are. Why? To enslave us to pills, diets, and surgeries. It lays the blame for all health issues at our feet — our ‘fat’ feet according to the government — but it forgets to look at environmental and nutritional factors. Chemtrails, hormones, genetically modified foods, and treated water (chlorine and fluoride) are major contributors to the rising diabetes, autoimmune, and cardiovascular diseases. The very ‘diet’ products we’re encouraged to consume (at higher cost mind you) aid in our deterioration. Additives and dyes in processed foods are killing us–not natural sugars and meats. But Obama’s health ‘cure’ will likely place everyone with a BMI over 25 on a pill of some kind.
And you and I? Fat Chance. That’s what. Fat Chance.
I like how the BMI score goes to the one billionth decimal point. VERY mathematical!
Thursday is Donut day at the office; needless to say, I felt a lot better after reading your article.
NPR also has an article on this issue:
Top 10 Reasons Why The BMI Is Bogus
It’s obvious this score is flawed when you have overweight people with healthy hearts and marathon runners needing triple-bypass surgery, but it won’t make any difference, except only in the minds of us who score over 35. 😉
Great article, Sharon. Thanks for keeping me informed!
Hi Darren! Funny, I almost linked to the NPR article you mention, but I figured there might be more a mathematician might bring more ‘weight’ to the issue!
Enjoy the donuts!
Oh, I did!
In fact, I think my BMI went up a couple of points. 😛
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