Just a quick one this week as I have to generate 2000 words by the end of the day for my masters degree and time is of the essence.
As a quick aside before we begin; if you ever read a headline that is a question the answer is always ‘no’.
A paper has just come out in JAMA that seems to be saying that being overweight isn’t as bad for your health as it used to be. The standard measure of measuring people’s body fat is the Body Mass Index. It is a rather crude measure that makes no allowance for body shape or muscle to fat ratio but it is very quick and easy to calculate and therefore has been a proxy for health for several decades now.
It is calculated by dividing your weight in kilograms by your height in metres squared. For those of us still using imperial units this is actually a complete pain in the arse to calculate as I have no idea how tall I am in metres and no one (in the UK) would measure their weight in kilos. Anyhow, if the answer comes out as 20-25 then you are considered to have a healthy BMI; 25-30 is overweight; 30+ is obese. Many athletes come out as overweight or even obese because they’re packed full of lovely dense muscle but the calculation doesn’t care.
For several years now there has been an unusual anomaly in the measure: overweight people live longer than ‘healthy’ people. Now, length of life is only one measure of healthiness but it is quite an important one, and there is no mention of what the quality of that life is, but it has been a bit of a fly in the ointment for sometime.
This new study looked at more than 100,000 adults living in Copenhagen from the 1970s to the present day. They found that the ‘ideal’ BMI for the longest possible life has shifted from 23.7 to 27 between the years 1976 to 2013. That is quite a large move and means that those squarely in the overweight category live the longest.
The authors don’t attempt to say why this might be the case, their study wasn’t designed to do that. They do speculate that it could be the improvement in managing high blood pressure and cholesterol and associated heart problems, but we can’t know for sure with this data set.
The reason that this study caught my eye was because it reminded me of one that I saw a couple of months ago about alcohol consumption. We’re all familiar with the lazy way that the media present studies on alcohol consumption: one day it’s, “..a glass of red wine per day makes you immortal…,” the next it’s, “…just looking at a liquor store will make you spontaneously combust…” The study I want to cover does an excellent job of picking apart the reality of the situation. I’ve intended to do a post on it for sometime but have been waiting till I have some more spare time to give it the attention it deserves. Suffice to say that there are complexities that are difficult to tease out and we may be seeing some of the same thing in the BMI data of the last couple of decades.
In two weeks time I’ll be free of studying for the summer and can spend a bit more time working here. I probably won’t go straight back to a post every day as I’ll just have to cut it down again come the new academic year, but certainly two or three times per week would be good. I’m rather looking forward to it.