I think this is the answer: posting calories increases calorie consumption because it increases cognitive load.

This would be predicted by empirical studies like this one:

Shiv, B. & Fedorikhin, A. (1999). Heart and mind in conflict: The interplay of affect and cognition in consumer decision making. Journal of Consumer Research, 26(2), 278-292.

that showed that subjects tasked with remembering a 7-digit integer were more likely to choose unhealthy food than subjects told to remember a 2-digit integer.

So, to get people to eat more calories, give them a bunch of three-digit integers to add!

(The Baba Shiv study was publicized in a Radiolab episode.)

Expand full comment


Nutritional labels are valuable not because of their influence on eating patterns, but because people who care ought to be able to know.

Expand full comment

I just added to this post.

Expand full comment

Multiple trials showing the information makes a difference, one trial by partisans showing no difference, and you choose for your blog ___?

Work harder on overcoming that bias, buddy.

Expand full comment

I did NOT say that I reduced my caloric consumption during a given visit or average visit. I said I benefited directly from the knowledge, and that's a very different statement. In several cases I have shifted my consumption and gained utility by doing so. I think of calories as a budget that I have to spend.

Think of calories as a currency. In one case, I order from a menu without prices and then pay the bill whatever it is, estimating what things probably cost. In the second case, I know what everything costs and choose what to consume accordingly. I will thus make better choices about what is worth the cost, but I may end up spending more in that case than in the first case because I can spend them more efficiently and without worry that I'll overspend. When I have no idea what the prices (calories) are, I often get risk averse.

There's also an effect across venues. I liked the idea of going to Cheesecake Factory until I saw a calorie-labeled menu and realized what they were up to, so I now almost never go, but on an average visit my consumption probably doesn't change much because otherwise why would I go there. On the other hand, I've learned I should be going to steakhouses more often than I was since I went to one that labeled, since I thought they were worse for me than they are, but if anything I consume *more* calories when I'm there because I feel like it's all right. Also brings to mind that people drive faster when they're wearing seat belts, but again even if they're not safer they're still better off.

I also don't think we can assume that the noticing and not-noticing groups would otherwise have consumed similar caloric amounts. I watch calorie counts because if I don't watch myself I eat too much; if I was naturally skinny I wouldn't care. I also tend to notice such counts more when I'm planning on eating things that I believe will be higher in calories, since I have more reason to bother. Of course, it could also run the other way for several reasons, such as those noticing trying to eat healthy and those not noticing being indifferent.

I have chosen restaurants over others because I wanted to see those counts, and it weighs substantially into my decision. I would pay a substantial sum right now to know the counts on the menus at several local places that I go to or order from regularly! In fact, I'm going to ask: Is there any way for one of us to get that information, by taking the food in question and measuring its caloric content directly? For sufficiently repeated interactions this strikes me as worthwhile if prices are reasonable.

Expand full comment

I was wondering whether the right information is being provided. What use are calorie counts if you don't know (a) how many calories you burn every day and (c) that an extra 3500 calories makes about a pound of fat? I used to eat fast food, and while I've never been overweight, I definitely didn't know the numeric specifics until like two years ago. I'm sure I'd heard it in mandatory high school health class, but I'd never paid attention.

Expand full comment

I’m trying to understand why anyone resists this idea, other than because they perceive the requirement as somehow diminishing the status of business people, while elevating the status of regulators, and because they think business people deserve more valorization, and regulators less, they instinctively respond against.I think the idea is that these anti-fat activists keep claiming that these poor, poor people are being forced and tricked into eating fatty foods by the big corporations, and that if only they were better informed they would eat healthier. This study shows that, in fact, the reason people eat huge amounts of calories is because they want to. The corporations are simply doing their best to provide the delicious high calorie foods people want.

Do people who eat fast food even know what calories mean? Or how many they burn in a day? Or how many calories adds up to a pound of fat?

People at McDonalds are innumerate?! What a shock!I'm surprised there's all this scorn being heaped at people who eat fast food. Stop being so elitist!

I eat fast food all the time because it's delicious, cheap, and saves time. I do make use of the calorie labels so I don't get fat, but fast food really isn't any less healthy than any other sort of food, as long as you eat it in moderation. I think the perception that it tastes bad and is unhealthy comes because it's regarded as low-class, rather than because of the way it interacts with your taste buds or metabolism. If gourmet food was cheap people would pig out on that and get fat.

When a food is advertised as low-calorie, I don’t think “healthy”, I think “small serving size”. To decide whether something is healthy, I look at the macronutrient ratios instead. Macronutrient ratios are good for making sure you get all the nutrients your body needs, but calories are more important if you're trying to lose weight.

Expand full comment

I had a feeling of deja vu, since I got into an argument with Hopefully Anonymous (linked from here) on a similar study months ago. Sure enough, it's the same one.

James, Zvi, your own self-reports aren't terribly solid evidence. The study showed that many people believed they ate healthier as a result, when their receipts showed otherwise.

David Gerard, did you not read the post? The were other restaurants (Wendys, Burger King, KFC,Taco Time). I don't know if any of them are that much healthier, but it's not "entirely within McDonalds".

Robert, I wasn't aware some people had aspartame allergies. Not that it's particularly surprising, just wouldn't have thought of it myself. Something to keep in mind.

If anyone wants links to actual studies rather than reporting, I provided some here. As I recall, Curt, they gave results for people who are not label readers as well.

I've got a review of Tom Naughton's "Fat Head" (made in response to "Super Size Me", though he fortunately remade much of the film to showcase Gary Taubes' and likeminded folks theories) in the works, but haven't finished it. You can watch Naughton's movie for free on Hulu.

Expand full comment

If you believe markets make good decisions, certainly you oppose hiding information from markets, no?

It seems to me that the fear of "sticker shock" is the force that would drive the restaurants to alter their menu, not some nebulous unmentioned future regulation.

Expand full comment

I prefer a rational consumer explanation. People already know fast food is loaded with calories. Labelling does not tell them anything they do not already know.

Expand full comment

You are drawing a lot of conclusions from a single, small study...

Expand full comment

One purpose of food labels is to try to cause those who don't pay attention to how they eat to start caring.

Another purpose is to allow those of us who do care what we're eating to know what's in our food.

I'd like to see labeling requirements go even further than they do now. Not for the first, paternalistic, reason, but for the second, full-disclosure, reason.

Expand full comment

I know that I have benefited directly from seeing the labels on foods and have used them to alter my food choices, and I know others that have done the same. It is absurd to think that they 'don't change behavior.'

There are any number of ways for this effect to be large and yet not to result in the average customer at a given restaurant consuming less calories. Perhaps they consume them in the same quantities but get what they would most enjoy. Perhaps those who care now go less often, and are counted less in the average. Perhaps once people know what they're buying the effective price goes down so they consume more without the cost of uncertainty. Perhaps many of the customers at McDonald's weren't looking to consume less calories, and some may actively have wanted to consume more for less money, in which case good for them. Perhaps as noted above overall conditions have evolved.

I don't expect I would on average consume dramatically less calories when I go to a given restaurant when I had the numbers in front of me, but I do know I would happily accept substantially higher prices to get that information.

Expand full comment

IMO we do not know what foods are more healthy than others for people who get sufficient vitamins, minerals and proteins which includes 95%+ of Americans and Western Europeans. Consider the more dietary fat less dietary fat debate and the lack of convincing data.

Expand full comment

If people ate at McDonald's less often as a result of seeing the labels, would the study have noticed?

Expand full comment

People at McDonalds are innumerate?! What a shock!

What are you going to tell me next, that pro-exercise messages in operas have no impact on public health?

Expand full comment