Wednesday, April 17, 2013

This is what a "normal" BMI looks like

112 - Sept 2009
Before I had my surgery, I used to get an argument with a certain someone on the web with a screen name of Jachut. She would constantly declare that a BMI of 24.9 was healthy and any BMI above that was not. Period.

I liked Jachut a lot and I loved her no-nonsense attitude about exercise and eating and how she didn't sugar-coat things or fool herself. But, on this one, she was full of shit. Period.

That's because BMI has absolutely nothing to
125 - Nov 2010 (IMAZ)
do with individual health. It's simply a formula that takes your height and weight and makes a ratio out of it. It was invented in order to put people into groupings (called populations) for the purposes of studying them.

114 - July 2009
The idea is that you can't put people into meaningful groupings based on raw weight because a 225 pound 5' tall person is in a very different weight category than a 6' tall person who weighs the same.

BMI was created to make a guestimate of how overweight or underweight a person is, but it doesn't take into account body composition or frame size so the categories are very rough estimates. And, again, they have nothing to do with an individual's own health. Statistics are not predicative to an individual anyway.

123 - April 2013
I don't actually think that means BMI is "meaningless" as some people will tell you. It does a good job, within it's limitations, of putting people into those gross categories so you can study them. Since that's what it was created for, that's a good thing.

But you need to be careful if you try to put too fine a point on it and make distinctions that aren't there -- like the difference between 24.7 and 24.9 or 24.9 and 25.1. Because there is no study that proves that people with a BMI of 24.4 are, on average, healthier than people with a BMI of 24.7.

113 - May 2010
In fact, at some point after looking at a bunch of studies, the experts in charge of such things got together and decided to change the ranges. So some people went to bed in the normal category and woke up in the overweight category, so to speak. Did they become unhealthy overnight? Of course not. Their individual health remained whatever it was before the categories were redefined.

To illustrate the wide range of weights that are covered by the "normal" BMI category, here are some pictures of me at various weights, all of which fall into the BMI range of 21 to 24.9.

As you can see, in some of them I have some pretty thin body parts (even if the whole is fine) and in some of them I am actually pudgy. Even sometimes at the same weight!

But they are all technically normal, if all you look at is BMI.

117 - Feb 2010

115 - June 2009
So what are we seeing here?

The ones I find the most interesting are the ones in the 120+ range. At Ironman Arizona, I'm 124-125 depending on the day and I'm almost as thin as I was at 112-113!

I'm not quite as thin because I have muscle covering some body parts that are a bit over-thin otherwise. You can't really see it because I have clothes covering my chest in the 120+ pictures. If I didn't, you'd see that my chest doesn't have that chicken-wing look at the higher weight that it does in the banner at the top of this blog. (However, right now I'm starting to get that look again because I can't lift weights. Grrrr.)

125 - Sept 2012
Otherwise, I pretty much look the same as I do in the Nov 2010 picture where I'm 125 and the picture taken last weekend where I was 123. I think maybe I have less "junk" around the middle at the lower weights. But it's hard to say because I have a lot of loose skin in that area and that obscures things.

129 - Jan 2012

But then we look at the pictures of me at 117 and I do think I look heavier than at 112-114. Also, some of my 125 pictures are pretty pudgy and we won't even talk about my 129 and 130 pix!

Okay, yes we will. I can't resist telling this story:

I met some people right before the 129 picture was taken who I hadn't seen since the summer of 2010 when I was 115-116 and looking similar to my May 2010 picture. Guess what they said? Oh, you look so much better now!
130 - Feb 2013

Um, really? Sorry, but I don't think so. I've got these arranged by size, not weight and there's a reason that picture is next to last!

I'm much happier with how I look in both the IMAZ pic (125), the Wildflower Training Weekend pic taken last weekend (123) and the Team Altered Reality pic (112). Yes, there's a 12 pound difference within those pictures. The difference is muscle. I was in much better shape at IMAZ than I was at Bike MS.

So there we have it... many different weights all in the "normal" range but some clearly overweight, some on the thin side and some "just right." I hope you find it enlightening.
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