Eating Too Much Leads to More Gas

Given my father’s medical specialty, you might think I’m referring to intestinal gas.

Actually, though, I am talking about the kind of gas you put in your fuel tank. In a recent study, researchers at the University of Illinois have calculated how much extra gasoline is being used each year because Americans weigh more and thus require more fuel to haul them around. The answer they come up with is an extra 938 million gallons of gas, or almost $3 billion dollars worth at current prices.

That sounds like a massive, headline-grabbing number, but really it’s not that big if you think about it the right way. On average, American adults are 24 pounds heavier today than they were in 1960. With, say, 250 million American adults, that is an extra 6 billion pounds of weight. Each extra pound costs you 50 cents in extra gas payments a year. So, from the perspective of an individual deciding to go on a diet, there could hardly be anything less important to your decision than the extra gas you will buy (not surprisingly.)

How important is weight gain to overall increases in gas consumption? According to this data, Americans today consume nearly 2 billion more barrels of motor gasoline than they did in 1960. If I understand the calculations they’re doing, you use the standard 42 gallons per barrel, meaning nearly 84 billion extra gallons of gas used today. If that is correct, then the weight gain explains only 1% of the growth in U.S. gasoline use. Even as low as that number is, I am surprised at its size; I would have expected this channel to be absolutely trivial.

What is truly amazing is not the link to gas, but just how much weight Americans have gained in the past 47 years — 24 pounds per adult!

(Hat tip: LLP.)


Also take into account that cars weigh less and are more efficient now than they were in 1960, so it probably balances out.


How dynamic are the results of the study. I have to imagine that any excersise leading to weight loss--and potentially reduced number of car trips--probably has an even bigger effect than the sheer amount of weight carried around by cars given the stated influence is 50 cents per pound.

Matt Nicholson

Of course the fact that large Americans will probably die younger means that the actual fuel consumption per person could well stay the same or even fall. On the other hand, they probably drive more, rather than walk, so perhaps it all balances out.


What about the fact that bigger people need bigger cars? I know a lot of big guys that feel they need to buy trucks, because they can't fit in cars


Cars weigh less than they did in 1960, as Unit says. But they weigh FAR more than they did in 1985 or 1990. Way more than 24 pounds more per car. All those extra airbags and anti-lock brakes and crumble zones and electric motors add safety and convenience, but at a cost of greater fuel consumption.

Ken D.

Where do the weight gain figures come from? Do they account for the changing age profile of the population? And what about height? My back of the envelope calculation is that even one inch of additional average height would account for maybe a quarter of that 24 pounds, and average height has increased over time.


however, the extra blubber provides a safety cushion if in an accident


"Of course the fact that large Americans will probably die younger"

You say its a fact. It may not be true.


On average, American adults are 24 pounds heavier today than they were in 1960 ... just how much weight Americans have gained in the past 47 years

Sorry, but this is sloppy writing. The adults from 1960 have not gained this weight -- they aren't the same people as the adults of 2007. The average adult from 1960 is more likely dead than obese.

The phrasing you want is something like "The average American adult weighs 24 lbs more than the average adult did in 1960."

And there are a lot more adults now than there were then. Given that, we should be able to compute the total weight of US adults in 1960 and today. Numbers I'm not sure I want to know.


"The average American adult weighs 24 lbs more than the average adult did in 1960."

I don't think this is clear enough. I think it should read,

The body of the average American adult person weighs an average of 24 lbs more or less than the body of the average adult weighed in the year of our lord, 1960.

Ken D.

I found the motherlode:

I just read the release, not the study, but that says that body mass index, which would incorporate the one inch height increase, was up about 12 percent from 1960 to 2002. That would be about two thirds of the gross (sorry) per person weight increase. I think there is still an aging-population adjustment to be made, but I will leave that to someone with more time and/or skill.


Blubber may not improve safety in accidents, but it may cause people to need less heating fuel at home.


This doesn't take into account the fact that we have a disparity in the socioeconomic level of those that are overweight. If poorer people are more likely to be overweight, and also less likely to drive cars and pay for gasoline, but rather utilize public transportation more, then they'll spend less on gas. so the numbers may be a little exagerated. i agree with you, though, the scary part is the obesity.


These kind of articles are interesting, but I feel it is a large jump to associate people weight with more fuel being consumed. I know in my case, I drive 5 times a week to my local gym and park to exercise. I drive about 3 miles. So for me, I drive roughly an additional 15 miles a week to not carry around the average 24 pounds. Thats roughly 750 miles or 25 gallons a year that I use. More than the 0.50 cents per each lb or $12. Mine cost would be around $65 extra.

And for speculation - if I live longer because of better health, I will use more total gas.


Has anyone ever done a study looking at studies that claim "x billion dollars wasted per year because of y"? I wonder if the total of the "wasted" money is larger than our whole economy. A simple google "billion dollars wasted":

$25 billion wasted by Windows XP
$8.1 billion wasted by employees wasting time at work.
$1 billion wasted printing phone books

etc. etc. This would be good for The Onion, but maybe it is beyond paraody...

Jeffrey S.

Here's another perspective... How much extra gas is being stored in fat in an adult body today.

There's 3500 Kcal in a pound of human body fat.
There's 31,000,000 cal in a gallon of gas.

Therefore, at 24 extra pounds of fat, an average adult person today is storing roughly 2.709 gallons of gas on his or her body. And, with 250 million adults in the U.S., people, in gross, are carrying roughly 677.5 million gallons of gas on their bodies. And lastly, with gasoline costing roughly $3 a gallon, American adults are hefting roughly $2.032 billion in excess energy.

In economic terms--considering Mr. Levitt's argument, as well as other postings--one has to question the overall opportunity cost of this country's obesity problem. Maybe the answer, though, comes from the industrialist, Henry Ford, when he said in reference to diet, "Americans are digging their own graves with their teeth."

Jody V

I asked myself this question a couple of weeks ago, without knowing what has been done and published. It is interesting that this has been studied with some rigor.

There are some corrollary fuel consumptions which need to be added to this total fuel cost...

what is the (fuel) cost of transporting food to the waistlines of Amerca, mine included.

If we assume the 3500 Kcal per pound of fat, and the efficiency of converion at 20%, which seems high but we can let that go for now, then we need to transport 5 pounds of fat for each pound an American carries.

Basically, how much food does a person need to consume to attain an extra pound of weight, and how much food does it take to maintain it?

Fat and pure suger are the most energy dense foods at 3500-4000 kcal per pound, we need to add the fuel cost of moving those foods to the palates of Americans. These calculations need to include the cost of cooking, cleaning up the excess dishes, throwing out the trash, and paying for the ambulance and medical crews.

I should get off my butt and do some growing field to disposal calculations to find out what the final bill to America really is.

This is not intendd to be an indightment (sp!) of Americans eating habits, but this may be a wake-up call for American nationalism. do we really want to eliminate the dependence upon foreign energy stocks? ...

Lose a pound for the good of America...

Walk to the gym... better yet, get a job unloading freight for Wallyworld/UPS/FedEx/... and sweat a little andlose a lot of weight while earning a couple bucks.



whoa 24 pounds! That's 92 kilos heavier i seriously think americans should start eating healthier