Obese people more likely to die in car crashes

New Scientist ^ | March 2, 2002 | Kurt Kleiner

[Paradox]

Obese people more likely to die in car crashes

09:30 30 March 02

Exclusive from New Scientist Print Edition

Heavier people are more likely to be killed or seriously injured in car accidents than lighter people, according to new research.

That could mean car designers will have to build in new safety features to compensate for the extra hazards facing overweight passengers. In the US, car manufacturers have already had to redesign air bags so they inflate to lower pressures, making them less of a danger to smaller women and children. But no one yet knows what it is that puts overweight passengers at extra risk.

A study carried out in Seattle, Washington, looked at more than 26,000 people who had been involved in car crashes, and found that heavier people were at far more risk. People weighing between 100 and 119 kilograms are almost two-and-a-half times as likely to die in a crash as people weighing less than 60 kilograms.

And importantly, the same trend held up when the researchers looked at body mass index (BMI) - a measure that takes height as well as weight into account. Someone 1.8 metres tall weighing 126 kilograms would have a BMI of 39, but so would a person 1.5 metres tall weighing 88 kilograms. People are said to be obese if their BMI is 30 or over.

The study found that people with a BMI of 35 to 39 are over twice as likely to die in a crash compared with people with BMIs of about 20. It is not just total weight, but obesity itself that's dangerous.

Crash-test dummies

While they do not yet know why this is the case, the evidence is worth pursuing, says Charles Mock, a surgeon and epidemiologist at the Harborview Injury Prevention and Research Center in Seattle, who led the research team. He thinks one answer may be for safety authorities to use heavier crash-test dummies when certifying cars as safe to drive.

Crash tests normally use dummies that represent standard-sized males weighing about 78 kilograms. Recently, smaller crash-test dummies have also been used to represent children inside crashing cars. But larger and heavier dummies are not used, the US National Highway Traffic Safety Administration in Washington DC told New Scientist.

The reasons for the higher injury and death rates are far from clear. Mock speculates that car interiors might not be suitably designed for heavy people. Or obese people, with health problems such as high blood pressure or diabetes, could be finding it tougher to recover from injury.

Richard Kent, an expert in impact biomechanics at the University of Virginia, thinks the new research has established a legitimate connection between obesity and severe injury or death. Because the research used BMI data, it has not confused taller (and therefore heavier than average) people with those who are overweight.

People who are obese might also be at risk because seat belts do not hold them as securely in a crash. "For example, a large amount of [fat] tissue between the restraint system and the bony thorax acts much like a winter coat: it introduces "slack" into the restraint system and decreases its performance," Kent says.

Journal reference: Accident Analysis and Prevention (vol 34, p 221)

Kurt Kleiner

[Paradox]

I use to read about the opposite, that fat people had more cushioning or something.

Seems like someday soon, the do-gooders will use this information in order to fuel legislation against fatty foods, or maybe a cheeseburger tax....

[BikerNYC]

Obese people more likely to die in car crashes

That's crazy talk, since they're less likely to fit into a car.

[TADSLOS]

There's a class action suit in here somewhere just waiting to come out.

[Leto]

Force = mass x accelaration, heavier person exposed to more force.

[tacticalogic]

But no one yet knows what it is that puts overweight passengers at extra risk.

I think they will find the answer to that intimatley related to the fact that force equals mass times accelleration, and that sufficient quantities of force tend to be lethal.

[toddst]

Let's just reduce this to basics -   "Obese people more likely to die." There, that wasn't so hard, was it?

[jlogajan]

Go here to find your BMI

[jlogajan]

Force = mass x accelaration, heavier person exposed to more force.

No, people who have heavier non-fat body mass do not have the same correlation of risk. It is a fat specific risk, not a mass specific risk. Re-read the article.

[TADSLOS]

Don't be so condescending with my sarcasm.

[jlogajan]

Me = BMI = 20.1

I'm immune to death in car crashes! ha ha ha -- splat ...

[RipSawyer]

Thank you, the real question is why any intelligent person would have a problem understanding why obese people are more likely to be killed. I had a conversation once with a Vietnam vet who said he grew up in a dirt floored cabin in Alabama. He told a story of a fat uncle who was standing on a ground sled being pulled by the mule he was driving. It seems the fat uncle lost his balance on a bump and fell off the sled. This would be a fall from a flat surface no more than six inches off the ground and moving no more than two miles per hour. He said his uncle "busted open like a ripe watermelon and his guts spilled out". I saw my own father fall from the top of my doorsteps, a height of nearly four feet, at the age of 81 and he got back to his feet with no injury because he was not fat. Why do people insist on making the simplest thing the subject of an investigation to find out what any country boy knew 100 years ago from simple observation.

[hopespringseternal]

BMI is bogus unless you are a couch potato.

At some company sponsored health screening, the health bimbo informed me that I needed to lose sixty pounds based on my BMI.

Funny thing is, I have no appreciable belly. It doesn't stick out or hang over my belt. Where am I supposed to lose 60 lbs from?

[SarahW]

"his uncle "busted open like a ripe watermelon and his guts spilled out". "

Thank you for sharing.

[dead]

Obese people more likely to die in car crashes

Fat people never get run over while jogging, so it’s a wash.

[jlogajan]

BMI is bogus unless you are a couch potato.

Well, BMI is for the "average" person of that weight/height classification. Obviously it can't apply to body builders who have a lot of extra weight that is all muscle.

But I think most body builders are aware to ignore BMI.

[Paradox]

BMI is bogus unless you are a couch potato.

The problem with the BMI is that it doesn't take into account the relative fat percentage. As an avid weight lifter (well, I USED to work out religiously), my BMI was always in the obese range, but I certainly was no where near obese. I had a measured/estimated 7% body fat. Obese is more like 30% or more.

[flyervet]

He told a story of a fat uncle who was standing on a ground sled being pulled by the mule he was driving. It seems the fat uncle lost his balance on a bump and fell off the sled. This would be a fall from a flat surface no more than six inches off the ground and moving no more than two miles per hour. He said his uncle "busted open like a ripe watermelon and his guts spilled out".

Thanks for the biggest laugh of the day! How did you keep from laughing in his face when he told you such a ridiculous story?

[jlogajan]

I had a measured/estimated 7% body fat.

What did you use to measure/estimate body fat. I have one of those electronic scales that measures the resistance up and down your legs as you stand on it. My body fat averages around 14% (varies a couple of percent either way.)

If I set the scale to "athlete body type" the reading drops almost in half -- but I don't really qualify for that type yet.

So I am wondering how accurate the scale is.

[RipSawyer]

I did not consider it a ridiculous story, only tragic. Perhaps you have no knowledge of the dangers of morbid obesity. I had an uncle myself who weighed over 500 pounds at one time. I am sure if he had taken any kind of a fall at all it would have been disastrous. As it was he died at the age of 53 from congestive heart failure. The point I was trying to make is that I cannot understand why anyone would be surprised that obese people are far more likely to suffer massive injury or death in a crash than people of normal weight. To me it seems as obvious as the sun rising.

[justshutupandtakeit]

Even a watermelon won't split like a watermelon when dropped from a height of six inches.

Methinks a few brews had gone around when that story was told.