A pledge of regular mediocrity

Perhaps the very worst thing about having only one substantial, researched and drafted post in this blog is that it set a precedent. It's a rather bad one, truth be told, because it has meant that, whenever I have sat down to write an entry in the three-odd years since I started this blog, it has looked slapdash by comparison. For that reason, I've started many posts and published none of them.

To help alleviate this issue, I have reminded myself of three things: 1) I started this blog as an outlet for the rants that bubble up from within me on a semi-regular basis, 2) I find journalling/ranting therapeutic, and (perhaps most importantly) 3) No-one reads the fucking thing anyway!

So, in that vein, I'd like to re-commit to writing this har blog. I'll aim to curb my natural anal-retentiveness about grammar, and will pledge today that I'll produce more, faster, crappier content than ever before. I'll use blue language at times, shamelessly write autobiographical posts, restaurant/book/game/film/TV/stage/music reviews, ill-conceived polemic rants, and generally re-dedicate myself to mediocrity. If readers have any problems, praise or other comments, they just need to follow two easy steps:

1) Pop into existence.
2) Use Blogger's handy commenting feature -- that's why it's there!

Anywho, this is mainly a note to self, a reminder that I like to talk/write shit and escape the oppressive shackles of the APA referencing style once in a while.

Allabest.

Love,
Dan

PS: I made a point of *not* proofreading this post, so if you find any glaring mistakes, omissions or heresies:

1) Tell me -- you'll warm the cockles of my black heart. Take that, clinical perfectionism!
2) Please -- and I can't stress this enough -- be mortally offended.
3) If you'd like me to change anything, slowly drink a glass of water, take a deep breath, and blow it out your arse.

New Blogger App

Sooo, this is just a very brief post to test out the new (to me) Blogger app for iOS. So far, it seems intuitive and elegant.

BMI: Bloody Massive Idiocy

When I started writing this post, I had just finished my academic semester, and was feeling very relaxed. Relaxed enough that I wanted to take a slice of my then-ample free time to write about something that has bugged the hell out of me for years. Unfortunately, inertia, changing blogs and going back to uni conspired to delay actual posting until now. Without further ado, however, I present: MY RANT AGAINST BMI!

The BMI, or Body Mass Index, is otherwise known (at least to me) as the arithmetically-derived pseudoscientific twaddle used to diagnose Australia as the 'Fattest Nation on Earth', having recently pipped the US for that crown. You heard it here first, kids. You know, unless you watch the news or read the paper, that is.

A little history (I'm drawing heavily on relevant sections from Fat Politics by J. Eric Oliver for my facts and figures). The BMI was developed in the 1830s by a Belgian astronomer and physiognomist named Adolphe Quetelet. He was interested, not in measuring human health, but in exploring the applicability of mathematical probability to humans. Quetelet collected data from French and Scottish army conscripts, plotting their heights and weights. He found that, for those who weighed roughly the statistical average for their height, weight was proportional to height squared. This is the source of the BMI formula (BMI = weight (kg)/height (m)²). As Oliver notes, however, Quetelet went a step further. He fallaciously reasoned that, since the weight of the 'average' conscript in his sample was proportional to their height squared, that weight and height should always exhibit this relationship. In case you're wondering, this relationship is the basis for 'ideal weight' calculations. It is also noteworthy that his sample was presumably comprised of only adult, white males, presumably with some form of standardised military physical training.

To provide a clearer example of Quetele's reasoning is 'bayad, m'kay', let's look at another example. Aristotle famously assumed that women were essentially passive, as Athenian women had no formal political role and little influence. In doing so, he treated something that was contingently true of Athenian women (their lack of political power) as a necessary fact about all women.

Anywho, let's look at a little testing theory. In order for any test to be useful, it needs to consistently gauge the target variable (e.g. weight). After all, there is no use for a set of bathroom scales that gives wildly varying results when the same person steps onto them several times in a row. Tests that deliver consistent results in this way are called reliable. Perhaps more importantly, it's crucial that a test measure what it purports to measure. Testing mavens call this property 'validity'.

Mechanically speaking, the BMI is a simple ratio of weight (in kg) divided by height (metres) squared: w/h². For a start, no such simple measure can be sensitive to different builds, proclivities for water retention, body fat percentages, bone density or any number of other variables that might reasonably affect this value. Examining Quetelet's methodology reveals that there is nothing magical or even special about this ratio -- it was simply an observed relationship in a subset of his very limited sample. Even if it weren't for Quetelet's poor reasoning in jumping from observation to injunction, his restricted sampling makes it impossible to make any valid inferences about the height-weight relationship for anyone not represented in his sample.

Let me clarify why this is a problem. Imagine that I went into the Olympic Village and took the body fat percentages of every female sprinter. I then went home and analysed the data and found that the average body fat rating was 14%. From that, I concluded that every man, woman and child of any age, fitness level and build should have 14% body fat. Hopefully, this reasoning seems as silly as it is, and this is precisely the logical process underlying BMI.

So this is the measure used on evaluating the health of nations; hence, it will be used to direct funding, justify lap band surgery and drive the diet industry. I'm not arguing that people are not getting heavier, eating poorly or exercising less than, say, 20 years ago. What I am saying is that BMI is an inappropriate measure of that trend. Empirically, the strongest correlations with coronary heart disease are not with BMI, but with levels of tummy fat. BMI is widely used not because it has any particular intrinsic merit, but because it is easy to measure. The problem, of course, is that it doesn't measure what it should, and that is a dangerous failing indeed.