What's your Allometric Index?

[The Last Conformist]

I'm sure I'm not the only one here who has wondered where the exponent in the BMI formula came from - afterall, for people with the same build, weight goes up with the 3rd power of the height, not the 2nd. This means that if you take a 2m tall guy with BMI 20 and shrink his linear dimensions till he's 1.5m tall, he'll be much slimmer than a guy who started out 1.5m tall with BMI 20. In fact, his post shrinkage BMI will be 15 - he's gone from the lower part of the normal range to deep into the underweight range while getting more athletic (since his strength - proportional to square of height - has decreased less than his weight). This seems, in a word, wrong.

The explanation, apparently, is that the BMI formula isn't from considerations of allometry at all, but from finding a best fit simple function of height and weight to predict body fat percentage. As probably everybody knows by know, it goes seriously haywire with tall muscular men.


Enough with the prolegomena. Just out of idle curiosity, I defined a modified index that is invariant under linear scaling, which could be called an "allometric index". It's simply your weight (in kilograms) thru the cube of your height (in meters). Put another way, it's your BMI thru your height (in meters). So, compute and vote!


Edit: If you end up exactly on any of the boundaries, vote for the higher option, ie. if your AI is exactly 12, vote 12-15.

 

[Tenochtitlan]

Exactly 10

 

[bhsup]

I'm in the 18-20 range.

 

[Adebisi]

12-15

 

[JoeM]

I'm with the masses (3 votes) in the 15-18 range with 16.

 

[The Last Conformist]

I should perhaps add that I don't have the physiological competence to say whether your allometric index is of any medicinal relevance. Please nobody start slimming because of this thread!

My own is 11.

 

[luiz]

12.27 for me.
(My weight is 74 KG and I'm 1.82 m tall).

 

[Birdjaguar]

I'm 12.175, looks typical, but is it good?

 

[sysyphus]

I'm at 14.985, barely enough to keep me in the 12-15 group.

 

[carlosMM]

I beat you by a few .xxx but am also quite close to 15.

 

[The Last Conformist]

One respondent is officially gutless.

 

[carlosMM]

One respondent is officially gutless.

... and gutted

 

[Perfection]

11.5

54.4 kilos @ 1.68 meters

 

[carlosMM]

11.5

54.4 kilos @ 1.68 meters

from now on, please spell your name 'perfection', not 'perfection' (kidding)

 

[Perfection]

from now on, please spell your name 'perfection', not 'perfection' (kidding)

HAHAHA!!!!

All you big lugs are gonna die when you get abducted by aliens and find you are to big to escape through the Jeffries tubes!

And, as always, I capitolize my name!

 

[carlosMM]

And, as always, I capitolize my name!

Hm, did you buy an old one or build a new one? where? Does it have columns out front?

 

[Perfection]

Hm, did you buy an old one or build a new one? where? Does it have columns out front?

My name belongs on a pedestal and so it resides. It's carved from fine salmon-colored marble and was a gift from the god Apollo.

 

[carlosMM]

My name belongs on a pedestal and so it resides. It's carved from fine salmon-colored marble and was a gift from the god Apollo.

how high is it? and does it have the same weight as you do? pictures, please!

TLC: how does that fit into your allometry?

[/threadjack]

 

[The Last Conformist]

TLC: how does that fit into your allometry?

It's height/width ratio is much higher than that of my name written in codfish-coloured granite. This indicates a higher degree of hubris in Perf's.


But let's get back on topic.

 

[Narz]

I'm too lazy to figure this out, you're gonna have to design an online allometric calculator.