There's been lots of chatter about Pepsi lately, so I thought I'd run with the theme. I don't have much to add to the media commentary - I'm just sad to see some of my favorite bloggers leave this space - but I've got plenty to say about soft drinks. And little of it will please Pepsi.

The first thing is that a soda tax is a great idea. Here's a compelling chart from a recent report published by US Department of Agriculutre's Economic Research Service (via Yglesias):


Some of these calories, of course, will be shifted to other categories of food - we'll drink less Pepsi, but we'll consume more Doritos. Nevertheless, there's compelling evidence that such "sin" taxes are actually quite effective. Just look at cigarettes: If you want to decrease the numbers of smokers, raising the price of cigarettes is the only proven solution. In fact, a 10 percent increase in the price of cigarettes causes a 4 percent reduction in demand. Teenagers are especially sensitive to these price changes: a 10 percent increase in price causes a 12 percent drop in teenage smoking. (The only bad news is that raising the price of cigarettes tends to increase the demand for marijuana. Apparently, the two products are in competition.) And let's not forget that nicotine is an extremely addictive substance. So I think there's good reason to think that a 10 percent hike in the price of sodas might be even more effective than a cigarette tax.

And while we're on the subject of Pepsi, it's also worth noting that diet sodas don't work.
Consider this recent paper in Behavioral Neuroscience, which found that rats fed artificial sweeteners gained more weight than rats fed actual sugar. Here's the abstract:

Animals may use sweet taste to predict the caloric contents of food. Eating sweet noncaloric substances may degrade this predictive relationship, leading to positive energy balance through increased food intake and/or diminished energy expenditure. Adult male Sprague-Dawley rats were given differential experience with a sweet taste that either predicted increased caloric content (glucose) or did not predict increased calories (saccharin). We found that reducing the correlation between sweet taste and the caloric content of foods using artificial sweeteners in rats resulted in increased caloric intake, increased body weight, and increased adiposity, as well as diminished caloric compensation and blunted thermic responses to sweet-tasting diets. These results suggest that consumption of products containing artificial sweeteners may lead to increased body weight and obesity by interfering with fundamental homeostatic, physiological processes.

The scientists argue that fake sugar is dangerous because it subverts a crucial homeostatic mechanism, as the the brain uses the sweetness of a food to keep track of its intake. More sugar implies more calories; the tongue is a natural energy detector. The problem with diet sodas is that they make this system unreliable, so that the presence of of intense sweetness no longer means anything. (And it's not just rodents: a similar effect has been observed in humans.) The hypothalamus gets confused. The end result is that we lose touch with the energetic needs of our body. Instead of eating to sate a hunger, we just eat. And eat.

This is the curse of soda: it's so bad for us that even diet sodas make us fat.


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Not sure I'm satisfied with the explanation in the diet soda paper there. The results are interesting, but if sweetness-perception is a homeostatic mechanism, shouldn't the consumption of sugar imitators reduce overall caloric intake? (Since your body thinks it's reached its quota of calories, even though some of them are "illusory" calories from Spenda, etc?)

Looks like the results imply that there's something qualitatively different in the way the mice are responding to sugar imitators, but what IS the difference? What exactly is the mechanism by which the body gets "confused" (a handwaving statement if I ever heard one)?

Everything Jue said.

"The first thing is that a soda tax is a great idea."

What business is it of yours to dictate how many calories someone else should consume?

Or by what foods and/or drinks they should be allowed to get those calories?

What you're proposing is penalizing people who don't act according to your will.

And you dehumanize people by treating them as livestock that you can manipulate via carrots and sticks.

Your first thing should be that a soda tax is an absolutely reprehensible idea.

My main concern is whether a soda tax will affect my beloved DIET Dr. Pepper and Coke ZERO, both of which have no caloric content but are delicious.

By Doug Henning (not verified) on 08 Jul 2010 #permalink

kazoolist@3 "Your first thing should be that a soda tax is an absolutely reprehensible idea."

Are taxes on cigarettes a "reprehensible idea"?

While I'm not sure if I agree that there should be a tax on soda, the problem with the "free will" argument is:

1) People are overwhelmingly bombarded with "information" that soda is "a good thing".

2) The cost of the product (like gasoline and cigarettes) does not reflect the overall cost of that product to society.

3) Since the medical costs of obesity are shared, people who over-consume soda penalize people who do not.

@jue surely there is a difference in response to the sugar-imitators, a disruption in the established relationship between the taste of sugar and subsequent increase in glucose which is detected in the hypothalamus. The 'confusion' would arise from the disruption to this (conditioned?) relationship. A good analogy would be unknowingly drinking non-alcoholic beer. The disruption to the expected consequence might lead you to drink more beer?

davep: The "cost to society" argument no doubt has merit but it is also often not nearly as clear-cut as many people like to believe. More to the point, it is the most insidious argument we've yet thought up to justify government regulation without end of private behavior. I have no doubt that this way of thinking will prevail, and maybe it's even for the good. But each and every time someone mentions "cost to society" I feel very, very scared.

By Francis Morrone (not verified) on 08 Jul 2010 #permalink

ugh... so much fail in this post.

-Is there any proof that having 300 calories/day of soda hurts the human body when that person has balance with the calories they intake and expend, gets at least .7g of protein per 1 lb of their body weight, and gets essential vitamins and fats? (Note that this is how it is very different from smoking at the onset.)

-Is there any proof that reducing soda consumption will not be made up for by other food calories? Again, this isn't cigarettes.

This is a fail of correlated, omitted variables. I'm shocked to see Lehrer use such shoddy numbers and stats. It just so happens that the vast majority who drink soda do not watch themselves on health matters at all. There is nothing that shows soda is harmful when it's a part of a well balanced diet.

And, if we're going to open the cost to society debate, can we start taxing the distance runners that end up with so many injuries to their legs? Can we start taxing anyone that plays competitive football, hockey, soccer, MMA for repetitive head injuries? Can we tax those that compete in those sports and many more for all the joint damage?

Then again, what about the benefits to society? Sugars are correlated with increased mental performance. How many breakthroughs are due to sugar/soda consumption?

This isn't cigarettes. We don't have causal relationships set up yet. It's a vast swamp of unknowns.

Obviously, I'm also biased in that I love most sodas. But, I am easily able to place soda within a healthy diet high in protein. My body fat percentage is in the low teens. I find it extremely unfair to have to pay higher taxes than someone getting their calories from a vegetable. This is people forcing their unsophisticated world views upon everyone else. You don't know what you think you do.

"The problem with diet sodas is that they make this system unreliable, so that the presence of of intense sweetness no longer means anything." I think that if companies continue to use artificial sweeteners and artificial flavoring then our taste buds will slowly shift so that we can tell the difference. My mother and I can both taste the difference between regular and diet soda's by father can't. I can also tell the difference between artificial juice and real juice. Maybe not reliably but I can usually tell the difference.

p.s. I'm not sure about the soda tax If we want to dictate health shouldn't we be taking donuts before soda.

Is it possible that there is another variable in the decrease of smoking, other than increases in tax? Maybe the prevalence of cancer among smokers?

Thank you for this one, Jonah!

"This is the curse of soda: it's so bad for us that even diet sodas make us fat."

No surprise that this post is met with some resistance.

Jonah has challenged the elements that form the daily habits of so many.

One cannot find fault with the soda credenda without also denying the virtue of this pervasive habit.

There is really nothing worse for the human body than loads of endless sugar.

Dropping the soda habit, alone, will shed at least 10 pounds from your bod without even working out.

Within a few short months, you can shed 20 pounds by simply letting go of the sugar addiction.

It is deadly and contributes in untold measure to the obesity epidemic.

No question.

I actually did this experiment a few months ago - wanted to lose 5 pounds, thought trading diet coke for my regular coke would be an easy way to drop the calories and lose the weight. Here's a summary of what happened:

Before: Regular coke heading out the door in the am, nothing else for breakfast; first "food" eaten around lunchtime; coke with lunch and into early afternoon. Dinner in evening with another coke, nothing else before bed.

After: Drank a diet coke on way to work. Go to work, famished by 9 am. Head to work lounge, eat cereal/donut/coffee/juice. Ate a bigger lunch. Bought a candy snack in afternoon. Ate dinner. Ate after dinner snack.

Net result: No change in weight.

Went back to drinking the regular coke the day I realized that instead of grabbing a regular coke before an afternoon clinic, I ate a bag of gummi bears that had 200+ more calories than if I'd just drank the coke.

Here's what bothers me: why would taste signals have such a blinding grip on appetite if the body has other markers (e.g., glucose detected by the hypothalamus) that also track how many calories have been consumed? After all, these markers must give the initial indication that sweet taste no longer reliably predicts calories; otherwise it seems the body would count non-nutritive sweetness as "illusory calories," as Jue said.

In any case, it is important to remember that non-caloric sweet tastes are an evolutionary novelty, so it is not especially surprising that modern animals respond maladaptively.

@Bret: On the intense running vs. smoking question, I think society views running as an expression of virtue, a productive activity in which people can be proud of their accomplishments. In contrast, essentially no one views conventional smoking as a skill to be cultivated or an achievement to be recognized. Based on this distinction, one type of self-harm is accepted as a lifestyle choice and another is regretted as an draining habit. It's not a clear line, but it's not anywhere near arbitrary.

By Jose Lopez (not verified) on 08 Jul 2010 #permalink

Right on! Soda, fast foods, and cigarettes are the number one reason for the so called health care "crisis". The only crisis is the one that we have created ourselves through the Standard American Diet (SAD) and self indulgent lifestyles. These three killers should all be heavily taxed so that those who chose to continue using them can contribute their fair share to the inevitable higher cost of health care due to obesity, diabetes, cancer, etc etc.

This has nothing to do with rationing the quantity of available choices, or creating a "food police" state. We should all be able to chose whatever we want to eat or drink, but those who decide to consume products that have a proven negative effect on long term health must be the ones to contribute to those future costs, and the only way to do that is through a consumption tax.

"The first thing is that a soda tax is a great idea."

What business is it of yours to dictate how many calories someone else should consume?

Or by what foods and/or drinks they should be allowed to get those calories?

What you're proposing is penalizing people who don't act according to your will.

And you dehumanize people by treating them as livestock that you can manipulate via carrots and sticks.

Your first thing should be that a soda tax is an absolutely reprehensible idea.

Posted by: kazoolist | July 8, 2010 2:11 PM

There's always got to be some libertarian clown who can only see one-half of the picture. Pepsi, et. al., KNOW their food is toxic. And they pay people to LIE about it and convince the "true believers," like you, in the joys of BEING EXPLOITED and PUT IN AN EARLY GRAVE by the Lords of Capitalism, which you imagine yourself to be but are not and never will be...

If we try to regulate the consumption by prohibition, we get increased crime, more potent and toxic products and increased consumption. Just like prohibition almost a 100-years ago. Just like the war on drugs now.

However, a tax will achieve the same thing and only punish those who choose to be idiots... And the taxes can go to pay for all the huge medical costs these soon-to-be porkers will bring down on us when their morbidly obese butts get on Medicare/Welfare because they're so fat they're disabled.

But failing to see all that in your hysterical over-reaction to taxes... You're as predictable as desert flowers after a shower...

Moses, how would you like it if I violently put myself in your life choices with very little scientific proof?

Again, there is no proof that soda is bad for a human if that person balances their calorie intake and outtake, gets a steady supply of protein, and gets essential fats and vitamins. NO PROOF.

If you want to tax obese people, tax obese people. Don't tax correlated, but non-causal, related activities.

If I had the choice; I'd prefer water (no lead or arsenic, please) + carbonation + caffeine. But all they seem to want to make available, is some form of Brawndo. (It's what plants crave.) And now the "plants" want to argue and debate over whether taxing it would be a good thing. Is it social engineering? communist meddling? promotion of the general welfare? pfft. Who cares?

The mindset that moralizes over our dietary behavior or desires to control the bodies and behavior of others, is often called fascism. But more properly, I think, you could call it codependency.

"If you want to tax obese people, tax obese people. Don't tax correlated, but non-causal, related activities."

are insurance companies allowed to raise premiums for overweight people? if so, good; if not, wouldn't that be more efficient than taxing soft drinks (and essentially the same as taxing obese people)?

re: taxing obese people (i.e. with the assumption that people who drink soda are obese): I drink 3-4 cokes a day, weigh 132 pounds at 5'8", and my total cholesterol level was less than my weight last time we checked it. So, drinking pop does not necessarily translate into unhealthy/overweight. Sorry it can't be that simple!

A state can slap a sin tax on sugar more easily than they can rescind a federal subsidy for corn and sugar production, but they are functionally pretty similar.

Making insurance more expensive for fat people doesn't strike me as something that would successfully inspire healthy living. So whether that's a good idea depends on whether your goal is to make people healthier (sin tax better) or to make sure that unhealthy people pay for their own health risks (fat-person premiums better). Of course if you believe in maximizing people's opportunities for personal responsibility, it is best to have no sin taxes and permit insurance companies to discriminate on the basis of any remotely behavioral measurement, even stuff that's sort of unfair (plenty of skinny people are unhealthy from eating too much sugar, but it's much easier to measure BMI than subtler elements of health).

I really think that, if your goal is to trick people into being healthy, you'll get a lot further by charging them more for unhealthy food and less for healthy food. Charging someone unhealthy money for being fat is too remote from the decision that makes them unhealthy- charging someone for drinking soda is much more direct.

Someone should run a PSA about caloried soda being better for you than diet soda, if the evidence is that good. I don't think it's terribly difficult to convince people to switch.

Sodas' deleterious effects are not confined to obesity and diabetes. We evolved in a relatively sugar-free environment. In addition to the rare honey treat or ripe fruit, our "sweet tooth" was satisfied by digesting complex carbs (e.g., yams) in the mouth after much mastication, or by being broken down in the stomach for a slow release of glucose. This is a far cry from high-glycemic-index substances like soda or candy. Their quick uptake messes up all sorts of organs from the pancreas on up. Our bodies don't know what to do with an embarrassment of riches (after all, glucose *is* precious for the brain and muscles), and the least of it might be a weight gain. The only good thing about that is its visibility. Who knows what incremental damage all that sugar is doing to your brain and liver?

We don't need a soda tax as much as we need a high fructose corn syrup tax.

Meh... I'm generally libertarian leaning in my views, but taxing soda is not the worst thing. However the whole "cost to society" argument is pretty weak when it is entirely based upon the liberal concept that our medical cost should be socialized. No socialized medicine = No societal costs for unhealthy behavior. Want to know how to make those who practice poor choices in their personal health behavior pay for their own behavior instead of society? Make them pay for their own medical bills.

Like I said, taxing soda isn't the worst of things. My real concern is about politicians suddenly viewing it as a new revenue stream, and tripping over themselves to find new things to spend it on.

I'm a big diet-soda drinker. I think your argument against diet soda is pretty weak. Besides some very good arguments from others here, I've both read of studies that have come to the opposite conclusion, as well as my own anecdotal observation that diet soda has worked for me with weight-loss. Additionally, drinking diet soda is exceptionally better for you than full-sugar drinks for a host of other reasons (ask a diabetic).

The real hole in this theory is that rats don't know that what they're drinking has no calories, humans do. It matters. To argue that is doesn't is to effectively argue that we should remove dietary-content labeling from all food.

One problem with sin taxes is their primary purpose is to increase revenue, not health. They are sold by governments saying that the revenue will go toward health care, but can anyone give me an example of that being the case?

If the taxes were going for healthcare and if the tax induced healthier behavior, then the tax revenue would fall as health costs fell... and the scheme would work. Can anyone give me an example of anything even approaching that?

What's more likely to happen is that health costs will not be substantially reduced because it's very unlikely that soda alone is a major cause, much less the only cause of ill health or obesity in most people. Couple continued high health costs with the tax money going into the general funds of whatever government entity is doing the taxes and all we have left are higher taxes sold to us on a falsehood.

IIRC, there was a study done where people were allowed to shop at a store with low prices for healthy food, high ones for unhealthy food. When the budgets were unchanged, people actually bought more unhealthy food because they had more money left over. I may not be remembering the study correctly.

BTW, I don't drink sodas because I've had surgery that makes drinking anything carbonated uncomfortable. I don't miss the sodas nearly as much as I miss beer.

why is it that when it comes to eating we always turn to the government to raise taxes to make people eat ... or in this case.... drink better. should we always make people pay more for making bad decisions. why do we penalize people for doing what they want. is it wrong for someone to eat something we think is wrong. should we start taxing people who speed or tax people who don't work out enough. there are things that are worse then soda. have you ever looked at a fancy restaurant menu they are just as bad any fast food but instead we think fast food is bad so we tax it. instead we should let people choose with out raising taxes. god forbid

By kenneth haynie (not verified) on 11 Jul 2010 #permalink

@Bret: Sure, it's possible for soda to be a small part of a balanced diet. However, it's extremely difficult, and MOST people are unable to balance caloric intake/expenditure properly.

There have also been studies that show that liquid calories are not registered the same way solid calories are, and therefore people who consume liquid calories tend to consume more calories overall.

I believe we need to go back to the days where drinking soda was a luxury, not an inalienable right. We drank soda much less frequently, and in much smaller amounts. We tax luxury items to a much greater degree, and I think soda should be included in that category.

alright, time to establish that you don't know what you think you know. It's not hard at all to balance sodas within a healthy balanced diet. That is pure bunk. I do it easily. The fructose alarmism camp is scary! It's not good science and it really makes me question Lehrer all the way around that he just goes along with it.……


I think it's great that you're able to successfully balance sodas with a healthy diet!

Unfortunately, just because you don't find it difficult doesn't mean that other people are able to balance their diets as easily or as successfully as you.

Seems like here's a good place to point to the increase in drink sizes at fast food restaurants (not to mention the free refills at the self-serve stations).

I just came across this interesting article (somewhat of a side note, but the psychology is interesting):

It's also not just about obesity -- it's about type II diabetes. Drinking liquid sugar in large quantities and with great frequency is one of the fastest ways to develop this disease.

Here are some other facts that I just pulled from the Center for Science in the Public Interet's "Obesity Fact Sheet":

- Children who consume more soft drinks consume more calories (about 55 to 190 per day) than kids who drink fewer soft drinks.

- A study conducted by the Harvard School of Public Health found that for each additional serving of soda or juice drink a child consumes per day, the child's chance of becoming overweight increases by 60%.

- A health-education program encouraging elementary school students to decrease soft drink consumption reduced rates of overweight and obesity.

My bottom line is that I agree that yes, it is possible to have an occasional soda... But people are drinking way too much of it, and encouraging people to reduce consumption is a good thing.

Know what you need to do to be compliant and avoid the risk while Translation Medical Insert, Translations Medical Insert and gain the perspective and position of a medical device industry expert.

The conclusion of the abstract on saccharin and rats went too far: it cannot be applied to the case where, say, sucralose has been added to coconut milk or bovine cream. In both these examples there are actual calories, so the sweet taste buds have not been fooled.

Popper would not have approved.

By leonRover (not verified) on 23 Jul 2010 #permalink

The University of Oxford's Shankar, Levitan and Spence published a study related to the idea of prior expectation on how we perceive food last year: Grape expectations: The role of cognitive influences in colorâflavor interactions (

This definitely seems related, as it is our prior expectations of the sweet-caloric relationship that are being subverted when we drink diet sodas.

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