Monday, August 06, 2012

Amassing mass

Prior to last week, excepting routine dental cleanings I hadn't been a medical patient in any capacity for nearly a decade. I have full employer-provided health coverage I've never used and I'm pushing thirty now, though, so it seemed as good a time as any to schedule a physical.

Oh no! With a body mass index of over 27 (the commonly used statistic for assessing overweight and obesity rates in the US), I find out I'm overweight. Obesity isn't that far over the horizon. When I ran cross country in high school, my BMI was around 23. My body fat then was 13%. Today it's 9%. 

A healthy AE
AE on the way to the morgue
I realize it's hardly novel to criticize the BMI, and as someone who relies heavily on the GSS' wordsum vocabulary test as a proxy for IQ, I'm the last person who should criticize imperfect metrics. Still, it's worth keeping in mind that the trends over time in the US towards conspicuously building muscle mass and increases in obesity rates are correlated to some extent. Half Sigma has pointed out that Burt Reynolds used to cut it as an onscreen strongman. He obviously wouldn't today.


Anonymous said...

The average American adult male stands around five feet ten inches tall. For that height, he has to weigh 190 lbs to get to a BMI of 27.3.

What percentage of 5'10" 190lb American men are ripped athletes as opposed to lard-butts? Just from looking at people around me, I'd guess 5% as an upper limit.

BMI is a guesstimate, but a more accurate one than word-sum.

Peter said...

Waist measurement is a much better determination of whether a man is overweight or not. It doesn't work quite as well for women, but is still moderately useful.

Olave d'Estienne said...

I trust weight to height ratio much more than BMI (which seems like a decent measure of skinniness, but who wants to measure that? "unskinny" isn't a useful concept ... but I'm preaching to the choir).

My only problem with waist to height ratio is that I don't know if I'm measuring my waist fairly. I'm always worried I'm "sucking it in" or "pooching it out". I usually just measure my belt, from clasp to the hole I usually use, but that is padded with trouser and I'm not sure it's technically "waist".

Jokah Macpherson said...

Did they measure your triglyceride level? That is a really useful measurement.

Anonymous said...

You do see a lot more heavily muscled guys today than you did twenty-five years ago. Some of it is due to better diet and exercise, no doubt. But I suspect there's a lot more doping going on as well.

CH said...

the trend toward musculature would primarily affect false positive rates of male obesity. i don't see too many women bulking up or hitting the weight room at the gym. if anything, the trend for women is in one of two directions:

SWPL chicks - aerobically lean
all other chicks - fat assed

Anonymous said...

Burt Reynolds had hair on his chest. So did Tom Selleck in Magnum P.I. At one time having hair on your chest was the epitome of masculine virility. Now it's considered gross.

I'm not complaining, since I don't have chest hair. I just think it's a change worth mentioning.

Audacious Epigone said...


That wasn't tested. My LDL HDL is 98:100 though, which my doctor did tell me was one of the better ratios he'd ever seen. Are triglycerides and HDL inversely correlated?

Andrew Oh-Willeke said...

Triglycerides, high cholestorol (both total, LDL and the wrong LDL/HDL ratio), and high blood pressure are all blood chemistry early warning markers of obsesity associated cardiovascular disease risk (e.g. strokes and TIAs, and heart attacks). Triglycerides can also be early warning signs of obsesity associated Type II diabetes risk.

Usually, well written statements of BMI and obesity links note that BMI is not too accurate as a health predictor for athletic people and that indicators like body fat percentage, body shape (e.g. waist size relative to BMI), triglyceride levels, cholestorol levels, high blood pressure and blood sugar levels are better indicators of the health risks associated with obesity.

Of course, BMI trends are perfectly valid, even if they are influenced by muscle as well as fat for some purposes - for example, for determining how many people can safely ride an elevator or how many seats an airplane should be designed to have, where average weight is the only issue, but theaverage people who ride your planes may have non-average heights.

I also wouldn't be surprised if high muscle, high BMI individuals suffered from some of the non-cardiovascular maladies associated with obesity (e.g. succeptibility to planar fasciitis, aka arch collapse, in your feet).

Overall, however, I suspect that buff men are a pretty modest factor in the rise of the percentage of the population that is obese as measured by BMI.

Jokah Macpherson said...


My understanding from reading Taubes is that they are.

I wonder if BMI tends to be a more accurate predictor of health for women. They probably have less variance in muscle mass as a percentage of total body mass.

pat said...

The great nutritionist Jean Mayer had an even simpler test. He suggested taking off your cloths and looking at yourself in a full length mirror. He said - if you look fat, you are fat.


as said...

You look nice.