Does fast food really make us fat?

by on June 3, 2008 at 9:21 am in Food and Drink | Permalink

Matsa and Anderson next looked at data on individual eating habits from
a survey conducted between 1994 and 1996. When eating out, people
reported consuming about 35 percent more calories on average than when
they ate at home. But importantly, respondents reduced their caloric
intake at home on days they ate out (that’s not to say that people were
watching their weight, since respondents who reported consuming more at
home also tended to eat more when going out). Overall, eating out
increased daily caloric intake by only 24 calories.

The researchers also find that greater access to fast food restaurants, as created by new highway construction, doesn’t much matter for weight.  Here is more, including a link to the original paper.

TheophileEscargot June 3, 2008 at 9:39 am

Interesting.

But note that 24 kcal per day is 8,760 per year. It takes 3,500 kcal to add a pound of fat.

So on this basis, eating out will cause you to gain 2.5 pounds per year.

TheophileEscargot June 3, 2008 at 9:59 am

Also, according to this Americans are 25 pounds heavier than they were in 1960.

So, if you consider this 2.5 pounds per year over many years, it seems plausible that increased fast food eating could be a major factor behind this change. It could even account for all of it.

So on the basis of the study it could indeed be fast food making people fat.

Joshua Macy June 3, 2008 at 10:21 am

It would only seem plausible to someone willing to assume that the average American ate out every day of the year. In other words, not plausible at all.

Sameer Parekh June 3, 2008 at 10:35 am

I’ve read recently that exercise rates have gone -up-. I’m sure, Theophile, that it is largely due to increased carbohydrate consumption, e.g. soft drinks.

Olivia June 3, 2008 at 11:20 am

I have not gone through this paper yet but I remember that Cutler et al. (2003) in the Journal of Economic Perspectives made an interesting point: individuals with self constrol problems are those most likely to be affected if the time delay before consumption is reduced (which is what happens when fast food is readily available). These are the ones who will likely spend more than is optimal on food and incur a welfare loss if the health costs of additional weight due to overconsumption are greater than the welfare gain from lower costs of time food preparation. Those 24 calories may well be an average, with most excess consumption concentrated among time-inconsistent individuals, whose BMI distributions is probably shifted to the right (i.e. more likely to be obese than their time-consistent counterparts).

Bill Harshaw June 3, 2008 at 1:27 pm

The cooperating states providing the data were: Arkansas, Colorado, Iowa, Kansas, Maine, Missouri, North Dakota, Nebraska, Oklahoma, Utah, and Vermont. Arkansas seems to be the only one in the top ten ranking of state obesity rates. Don’t know whether that could affect the conclusions.

David June 3, 2008 at 3:29 pm

Other studies have shown that people are really bad at estimating how many calories they’ve eaten. I think I’ll stick with Seth Robert’s theories about what makes food fattening.

12345 June 3, 2008 at 5:06 pm

(1) While people probably spend more time formally exercising now than they used to, I would wager that the level of informal exercise people do (housekeeping, manual labor, walking around, etc.) has diminished considerably in the last few decades due to technological advancements, TV, computers, increased use of cars to get around, a shift towards white collar jobs, etc. So while people may be going to the gym more, it doesn’t mean they’re still burning as many calories.

(2) Also, wouldn’t high carb drinks such as sodas, sweet tea, milkshakes, juices, etc. be included in any study of fast food? After all, it is a part of most value meals.

(3) “It would only seem plausible to someone willing to assume that the average American ate out every day of the year. In other words, not plausible at all.”
Probably only a few people eat out once every single day, but I think the average times a year that an American eats out is higher than expected. After all, consider when people are on vacation — many probably “eat out” for the entire trip, all 3 meals a day. That could make up for weeks of not eating out.

(4) I agree with the poster above – the blame (if any is to be had) is not just on FAST food restuarants, but on all food restaurants, which present even more high-calorie options than fast food restaurants do (Applebees, TGIFridays, Olive Garden, Red Lobster, Outback etc.)

Gannon June 3, 2008 at 5:57 pm

Still, the US is by far the fattest nation in the world, much fatter than Great Britain (the second fattest nation in the world).
Something environmental must cause that, since the Germans who have the same germanic genes are much thinner and fitter.
Explanation anyone?

Andy June 3, 2008 at 6:16 pm

Weight gain isn’t simply a matter of eating more calories. Two people of identical size and physical activity could eat the same number of calories and one could lose weight while the other gains weight.

Gannon June 3, 2008 at 7:50 pm

Thanks Michael Keenan. But I meant real countries, not small islands in the pacific with a few thousands inhabitants. The only real country that seems fatter is Kuwait: and even Kuwait is extremely small. Also, classifying people with a BMI between 25-29 as fat is stupid. Real fatness and significant health problems appear only on people with BMI’s over 30.

foxmarks June 4, 2008 at 12:53 am

I went to Varangy’s suggested video. Huh? Some dude challenges my “faith in the laws of thermodynamics†? And I’m supposed to then believe he can explain a complex biochemical process?

I get the bit about defining obesity as eating too much being circular. That’s a linguistic problem, not a chemical problem. He seems to conflate the judgment/definition of obesity with the biochemical process by which fat is accumulated.

Anyone have anything more meaty on Taubes’s meme-smashing hypothesis? Lacking that, I’ll stick with the well-tested hypothesis that USA (or anywhere) is fat because caloric intake exceeds caloric demands.

People may be weak at estimating their intake, and ceteris paribus, those 24 daily calories make 2.5 pounds in a year. But everyone knows when their pants get too tight. And everyone knows that if they eat less, ceteris paribus, their pants will get looser.

Ultimately, USA is fat because we’re O.K. with being fat. It’s a choice. And a judgment that fatter is–or is not–acceptable.

Varangy June 4, 2008 at 10:39 am

@foxmarks

There is no violation of the first law of thermodynamics.

Their thinking is that energy in (what you eat) and energy out (what you use) are the independent variables with delta E being the simple difference between the two.

Taubes contends, with an enormous amount of reference material, that the composition of your diet actually drives the delta E, then your body does what it needs to do in order to either “force” you to eat more (by triggering hunger pangs for example) or by changing your base metabolism or activity levels. The laws of thermodynamics still apply. It’s just that your body changes its requirements dynamically. In this model, obesity is not a failure of willpower or laziness (gluttony and sloth), but rather a biological imperative. It treats the body and metabolism as not just a calorie counter, but as a metabolically active organism. This perspective is more consistent with the results of multitudes of studies than the inert metabolically static model.

If it is not clear, what Taubes is saying that the causality is reversed and CalIn – CalOut are a function of DeltaE.

This is heresy in the ‘science’ of nutrition.

@Cliff

I don’t think anyone thinks of Taubes as genius. Nor he of himself, as far as I can tell. Simply a very smart and studious journalist. What do stupid things do you he says?

As far as carbs driving insulin driving fat accumulation not being radical — it is hardly widely accepted/mainstream – except by the Atkins folk – if it were, we wouldn’t have a nutrition industry devoted to ceaselessly churning out useless diets du jour.

IMHO what drives obesity in this country is farm subsidies that subsidize high glycemic/carb foods, that drive their prices down, and not only do they taste good (I love me some McD’s fries), but they are subsequently cheap, therefore demand is high – especially among the poor. The carb calories per dollar spent ratio at any fast food restaurant is ridiculously high. It is impossible for even a homeless person to starve to death, a few bucks a day, and he has more than enough to eat.

On a personal note, I have been eating a hyperlipid diet and have lost a large amount, very very rapidly. And no, I don’t eat fewer calories than before.

ielerol June 4, 2008 at 9:52 pm

Ultimately, USA is fat because we’re O.K. with being fat. It’s a choice. And a judgment that fatter is–or is not–acceptable.

yeah it’s all those Americans who are totally ok with being fat who are spending billions of dollars a year on weight-loss products.

geo October 27, 2008 at 9:51 pm

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Jessica(: October 27, 2008 at 9:53 pm

you’re silly.

club penguin May 19, 2009 at 9:36 pm

Metabolism expands or contracts to accommodate increased/decreased caloric consumption. You really have to get over a certain threshold before any weight change results. Both anecdotal and scientific evidence supports this.

payday loans vancouver May 4, 2010 at 2:39 pm

The scientists found that the group fed the high energy density diet put on fat at an alarming rate, while those eating the low energy density foods actually lost body fat. More research on people living in the UK and in Africa, as well as analysis of the composition of junk food, confirmed that fast food meals are a fast track to lardiness.

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MSG is added to food for the addictive effect it has on the human body.

stretch marks November 30, 2010 at 5:16 am

Depends on the regular menu you are ordering. If you order foods with lots of fats and carbohydrates then you could gain weight.

how to win the lottery February 8, 2011 at 1:21 pm

Weight as a function of “Calories In, Calories Out” (supposedly obeying the laws of thermodynamics) is likely dead wrong. Gary Taubes has demolished that, now dangerously arcane in my eyes, meme a while back. Funny how we have all been fooled for so long. …

sports betting system February 16, 2011 at 12:02 pm

If it is not clear, what Taubes is saying that the causality is reversed and CalIn – CalOut are a function of DeltaE.

detox diet March 3, 2011 at 9:29 am

Thanks Michael Keenan. But I meant real countries, not small islands in the pacific with a few thousands inhabitants. The only real country that seems fatter is Kuwait: and even Kuwait is extremely small. Also, classifying people with a BMI between 25-29 as fat is stupid. Real fatness and significant health problems appear only on people with BMI’s over 30.

Freddie Swarkcin March 4, 2011 at 2:33 am

I possibly could state it one other way, maybe to square with Taubes’s not-really-scientific explanation. Everyone knows when they do not fully satisfy their hunger constantly, their pants can get looser. Regularly eating beyond hunger makes pants tighter.
regards,
MSP

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