I do this at home, without clothes
In my last post I wrote about our upcoming generations and their obesity issues. Unfortunately, as you might have easily been able to predict, that carries over into adulthood. The same issue (Feb 1, 2012) of the Journal of the American Medical Association (usually called JAMA) had several articles on adults also. To begin with the National Health and Nutrition Survey (NHANES) looked at the body mass index (BMI) of men and women from 1999 through 2010.
"AARRGGHH" you say, "Why the hell should I care about whatever BMI is enough to try to understand it?"
Well, that's a tough question, I admit. But BMI is the standard way of deciding if a person is too thin, normal, overweight or obese. So let's give it a try.
Your BMI is a number calculated using your height and weight. If you weight 250 pounds and you're a seven-foot tall basketball professional center player, you're unlikely to be obese. But if you're five foot, six inches tall, and don't exercise at all, like the adolescent I was reading about recently, you're far too heavy. In the first case, the athlete has a lot of muscle, whereas the youngster is almost certain to be carrying around a lot of excess fat.
For a long time physicians just weighed their patients. That plus eyeballing their bodies in an exam room works for most people. Then along came the BMI as one way of getting a little more scientific. I looked online for the history of the use of body mass index as I suspected it was "invented" by a European (it was). It certainly seems to me to favor the metric system. There it's easy to figure out your BMI; you divide your weight in kilos by your height in meters. It's much more complicated using pounds and inches (BMI = weight in pounds divided by height in inches squared and that number is multiplied by 703) The CDC explanation of BMI is helpful and also supplies a "widget" you can download and a calculator if you just want to bookmark the website.
height counts, for adults too
So now you've (hopefully) figured out your own BMI; What does it mean and how reliable is it?
First the numbers: most people with a BMI under 18.5 are skinny, underweight. That probably excludes a whole passle of long-distance runners. Most people with a BMI over 18.5 and under 25 are in the "normal" weight category. I used the CDC calculator and my number is 20.5. Most whose magic number is 25+ and less than 30 are overweight and almost anyone whose BMI is over 30 is obese. The teenager I mentioned above has a BMI of 40.
Okay, you say. Now what do I need to do once I know what category I'm in.
I'd start with the eyeball test. Do you have a roll around the middle? In early 2009, weighing only three pounds more than I had for twenty years, I clearly did. I made up my mind to do something about that excess flab, knowing that fat in the belly also implies arteries that are narrowing down.
After losing thirty pounds and keeping it off, I bounced up after the Superbowl and went back on my diet, i.e., consuming fewer calories. I went to a meeting last evening; there were lots of goodies, but I ate only carrots and cucumbers. This morning I'm at 148.2 pounds, smack dab in the middle of the three-pound "ideal weight" range I decided on.
Harvard Medical School just published a piece titled "Choosing the diet that will work for you." The central theme is cutting calories.
Tags: BMI, body mass index, Obesity