Balancing pleasures

February 23, 2007 12:20 AM

One cigarette shortens life expectancy by about 11 minutes. How much time do the following take off: One drink over the recommended limit? One burger for which the calories are not burned off? Preferred units: assume a drink to be one UK unit of alcohol: 10ml or 8g pure alcohol. Assume a burger to be one Big Mac: 540 kcal.

I've Googled around and haven't found much data for alcohol. Made some very crude calculations for the burger. Apparently a BMI over 45 means 20 years less life. Assuming an average height of 5'9', I make that 61.2kg overweight. Assuming 7000 kcal to gain a kilo, I make that 0.04074 minutes lost per calorie, that comes out to 9.2 days lost per Big Mac, which seems much too high.

posted by TheophileEscargot to health & fitness (14 comments total)

I call fraught on all of these statistics. The amount of statistical error in prediction life expectancy to within minutes, days, weeks, months, or even +/- one year would blow your confidence values to high heaven...

...makes great headlines for rags like USA Today though.
posted by dendrite at 1:08 AM on February 23, 2007

Well, there's a degree of uncertainty of course. But I don't see why you can't do a rough comparison between them, especially since there may be a huge difference between them.

I think the big problem would be non-linearity: it could be that the twentieth drink over the limit is more damaging than the first. Even so, that ought to show up in the statistics somewhere.
posted by TheophileEscargot at 1:14 AM on February 23, 2007 [1 favorite has favorites]

Having one -- just one -- Big Mac is not going to shorten your life at all if you have an otherwise healthy diet. Having one -- just one -- cigarette probably is no worse for you than breathing city pollution or sitting around a smoky campfire.

For the cigarette stat, they just compared the life expectancies of smokers and nonsmokers, calculated how many cigarettes a smoker smokes, and did some simple math.

But everyone eats, so you have to ask something more like "Compared to people who eat (some healthy alternative?), how much shorter will your life be if you eat a Big Mac for lunch every day?" And even then, it's not easy. Compared to people who eat what healthy alternative? It would be better to try a calorie-based comparison: people who eat 100 percent of the calories recommended have a certain life expectancy, people who eat 1.5 times as much have a certain life expectancy, people who eat twice as much have a certain life expectancy, and try to come up with a prediction based on how many extra calories you eat each day.

Drinking might be easier. Compare the life expectancies of drinkers and nondrinkers (insurance companies and anti-alcohol cults must track stuff like this), then do the same sort of math they used for smoking: average number of drinks a drinker has, etc. But drinkers will come back with reports that say a certain amount of drinking actually improves your health -- there are always stories like this in the wish-fulfillment section of the news, next to the "chocolate is good for you" and "rich, beautiful, famous person has big problems" stories.
posted by pracowity at 1:50 AM on February 23, 2007

one Big Mac: 540 kcal

Isn't that number off by a couple orders of magnitude?
posted by Kirth Gerson at 2:25 AM on February 23, 2007

Watch Supersize Me. Guy lives on nothing but McDonalds for a month. It wont answer your question directly, but it will show you what it will do to your body.
posted by Solomon at 2:38 AM on February 23, 2007

one Big Mac: 540 kcal

Isn't that number off by a couple orders of magnitude?

It's what their US website says. Other resources give it as a bit bigger: 590 according to NutritionData.com. Calorie is a somewhat confusing measure though. A Calorie with a capital "C" is equal to 1,000 calories with a lower-case "c". I believe UK packaging tends to use "kcal" where the US uses Calorie.
posted by TheophileEscargot at 2:39 AM on February 23, 2007

Kirth: Nope, nutritional Calories are with a capitol "C" which means a kcal of energy.
posted by dendrite at 2:39 AM on February 23, 2007

One cigarette by itself does nothing, but twenty a day, every day, for years, that is bad. One Big Mac by itself does nothing, but twenty a day, every day, for years, well, you would probably never get to years.
posted by caddis at 4:19 AM on February 23, 2007

The problem with your BMI vs. life calculation is that it's not a linear relationship. For instance, this study (PDF) says that increasing from a BMI of 30 to 35 causes less than a year of decreased life expectancy.

That is 203 vs 236 pounds, or 214 Big Macs, or about 1/2-1 days per Big Mac.
posted by smackfu at 5:54 AM on February 23, 2007

How can I eat a burger and not burn off the calories? I mean I'm just sitting here on MeFi and I'm metabolizing calories, imagine how many more I'd burn walking to my car and driving to McDonald's for my third Big Mac of the morning. I think the assumption that 100% of a Big Mac's calories will be converted to fat is part of what's driving such a high life-expectancy-shortening.
posted by revgeorge at 6:38 AM on February 23, 2007

think the assumption that 100% of a Big Mac's calories will be converted to fat is part of what's driving such a high life-expectancy-shortening.

Well, and it's not just the idea that a Big Mac makes you fat that could shorten your life expectancy...there's also the saturated fat and cholesterol angle, which could lead to heart disease.
posted by cabingirl at 7:03 AM on February 23, 2007

This is a made up number invented by people who want you to stop smoking. You should stop smoking, of course, but you should also take this "statistic" with a grain of salt. It's completely meaningless, as will be any other number that attempts to tell you what one of anything will do.

The point is, while smoking is bad for you, the effects build up. Cigarette 20 is much worse than cigarette number 1. Cigarette 50,000 is much worse than cigarette 20. You're trying to take a harm that progresses geometrically, and put it on a linear scale. For every increase in X, wow much does F increase in F=X^2?

The answer is, it depends where you started.
posted by kingjoeshmoe at 9:34 AM on February 23, 2007

smackfu: Thanks for your answer!

I think I get a slightly different result from your data though. I follow you up to the 214 Big Macs. But at 8 766 hours in a year, I make that 41 hours per Big Mac assuming it takes one year of life off.

Regarding burning off the calories: I think if you ate it as part of a normal meal you'd burn most of it off. I was thinking more along the lines of comfort eating or binge eating, where you just go and eat something, not necessarily a burger, purely for pleasure or reassurance. Even then though, you can diet off the extra weight later, whereas you can't un-smoke a cigarette.
posted by TheophileEscargot at 9:39 AM on February 23, 2007

the human anatomy is made up of 9 different "systems". the reason that sort of data is quoted for smoking but not for big macs, is because it is a lot easier to associate the typical effects on smokers and non smokers, because they are two distinctly independant groups (statistically easy). it is obviously much more difficult to statistically isolate the effect of big macs. i would be suprised if epidemiologic study could accuarately isolate any of the components of a big mac for it's effect on health. however the effects of alcohol, i believe, should be directly comparable. at first i thought your question was silly. but after some reflection, i think the reason this sort of data is usually aassociated with smoking but not drinking is only due to sociology. the long term effects of drinking cannot be denied, but are less socially taboo than tabacco now. so i dont have an ans, but would love to see a study directly comparing ppl who smoke regularly only, vs ppl who drink regualry only, vs ppl who don't do either.
posted by edtut at 2:56 AM on February 24, 2007