Scientific American has a pretty interesting interactive graphic (there’s a non-interactive version below) that shows the trend, over the past 15 years, in five categories: heavy drinking, binge drinking, smoking, obesity and exercising. The top three causes of death are heart disease, cancer, respiratory diseases and too much eating, drinking, smoking and laziness are all causes of all of them, so this is important stuff.
However, it’s not easy to tell how much the figures changed using that graph. For example, binge drinkers went up from 14.1% of people to 15.1% and exercisers went up from 72.1% to 76%, which seems like a bigger deal, but in reality they both grew by about the same percentage. So instead of falling into the same trap, here, the stats are presented like stocks and ordered by the magnitude of the change, followed by the issues with the numbers:
- Obesity: +74%
- Heavy drinking: +69%
- Tobacco use: -24%
- Binge drinking: +7%
- Exercise: +5%
So, obesity and drinking are way up, tobacco use is down a pretty healthy amount, and binge drinking and exercise are slightly up. Since exercise hasn’t changed that much, the giant increase in obesity can only be blamed on our diet, which makes sense given all the cheap food. That means we’re eating and drinking a lot more than we used to 15 years ago. And, thanks to the prolonged public education campaign, we’re smoking a good bit less.
And now, for the problems with the numbers
For binge drinking and exercising, the questions used are pretty ridiculous. We’ve talked about the binge drinking definition issue before: having five beers in five hours, five beers in one hour, and fifteen beers in five hours are all counted as binges. And the question asked about exercise is if you’ve done physical activity in the last month; if you helped someone move last week, that would count as exercise. Smoking is defined as “current smokers”, and there’s no category for the many people that are casual smokers and would not identify themselves as “current smokers”.
Heavy drinking is defined as having more than two drinks per man per day, but other researchers define it as more than three per day, including the study that showed conclusively that heavy drinkers live longer than teetotalers. Which brings us to the other problem: if drinking heavily is a habit important enough to our health to be tracked, then it seems like abstaining from alcohol should also be. The fact that it’s not, indicates that some morality factor is also present in the surveys.
Obesity is defined as having a BMI of 30 or more. The BMI is a 200-year old measure with such severe problems that it actually says about 40% of obese people are not obese. Why? Because it only uses height and weight, which is great for easy research, but awful for figuring out how fat someone is: if you have a lot of muscle and no fat, it will say you’re overweight. If you’re nothing but fat and bones, it’ll say you’re normal weight. Ideally, obesity would be defined by body fat percentage, not BMI, but that would be impossible to figure out over the phone. Bottom line: the survey says 27% of Americans are obese, but that number is probably more like 45%.