On BMI, Smoking and Physical Fitness

Quite often amongst libertarians there’s a ‘drinkin’ smokin’ and ahm-a-gonna-continue-coz-you-ain’t-gonna-stop-me attitude’. Because the BMA advises something, some libertarians willfully do the opposite.

I entirely understand the wish to blow the smoke of an unfiltered Senior Service into the face of any public-health busybodies I see. There’s enormous glee for example in the reporting of the meta-study released recently which suggested the slightly overweight live longer than those in the “healthy” BMI range. This is something that I thought was long-known. The VERY underweight live the longest, as near-starvation prevents some damage caused by free-radicals in cells during metabolism. We all know what healthy people look like, but it’s apparently just as healthy to carry a bit more weight as you age. The findings of the report are not surprising.

BMI was invented in the 19th century, when people were calorie constrained, cars hadn’t been invented and everyone was skinny, worked in manual labour, and walked, rode, or cycled everywhere. “Normal” was different back then. However BMI’s not a bad rule of thumb. Normal these days is a bit overweight, and certainly not doing the exercise or suffering the occasional bout of hunger for which nature designed us.

The key is muscle. If you’re carrying muscle, and we carry a lot more of it than our great-grandparents, you’re active, a bit of extra fat isn’t a problem for your body to bear, but big muscles are heavy and so push you into “overweight” on the BMI.  If you’re built like a jockey’s whip, you’re completely sedentary and have an unhealthy lifestyle, you can have quite a high fat percentage and a low BMI as fatty tissue is less dense than muscle. Catwalk models have bad skin from make-up and a diet of cocaine, bulimic vomiting and fizzy white wine yet fall at or below the healthy range. Most professional Rugby Players, on the other hand are “obese” thanks to their large muscle mass. There’s no doubt which looks more healthy (without makeup).

I’ve never been a heavy smoker, but I have recently got into the habit of enjoying a cigarette or two in the evenings when I get home from work. I have for one reason or another been without a bicycle for much of the last few months. I’ve been drinking nearly every day and eating too much. I’ve not been taking exercise. I’ve got a bit fat. My BMI is 25.6. Very slightly over the border into overweight. And that’s probably about right. Fat, but not dangerously so. It certainly doesn’t help anyone who isn’t a professional athlete to see the BMI and think “Overweight is good”, because it isn’t.

Just a week of running and swimming each evening, and giving up the cancer-sticks entirely and cutting down the booze, I feel great. The first run was horrible. The second wasn’t much better. But on the third, I felt I’d cleared out some crap from the lungs and I enjoyed it. From previous bouts of fitness fanaticism I find at first you hate it. Then you start to enjoy it. Then you start to need it.

What interests me in the epidemiology is to what extent is the huge health penalty with which smoking is correlated to do with the harms of smoking itself, and how much is to do with the fact that people who smoke are also less likely to make healthy choices with exercise and food? It’s my belief that for day to day well-being, being sedentary is worse than light smoking. If you take regular exercise, I suspect you can get away with a fag with your pint afterwards. But I’m not a doctor, nor am I a public health epidemiologist. I don’t know.

Just because some nannying doctor tells you something is good or bad for you, doesn’t mean he’s wrong. Feeling hungover, lethargic and listless is not as good as feeling bright, cheerful and healthy. Pretty girls prefer men with toned muscles. You’re better in the sack with those pretty girls (or even your significant other) if you take some exercise. Fit people suffer less depression and have higher self-reported happiness. You’ll live longer and so generate more personal utility from the taxes you pay as you burden the NHS with your longer senescence. You sleep better after exercise, and are so more productive when you get up. Live fast, die young? Sod that. Live fast, die old, that’s my motto.

I’ve just started an exercise regime. I’m not just happy about it, I’m smug about it too. Hate me.