Why Imagined Indulgence Helps Us Diet

What makes decadent waffles so damn satisfying in the morning? Is it the optimal balance of crispy and soft textures? The fat in the whipped cream? The sugar content? It turns out that there’s a factor beyond the actual food: your frame of mind. A team of researchers at Yale just performed a clever study and found that you feel fuller and more sated if you believe you just ate something indulgent.

As with most psychology experiments, the study involved lying to people. Subjects were given a milkshake on two separate occasions but were told that one contained a whopping 620 calories and the other had a more sensible 140 calories. In reality, both shakes were the same – right in the middle at 380 calories.

Before and after each test, the researchers monitored the subjects’ ghrelin levels as a measure of how satisfied they were. Ghrelin – the hormone which triggers hunger – increases and spikes before meals, then drops off after people eat. If the calorie content were all that mattered, there would be no difference in reactions to the two shakes. But there was:

Results: The mindset of indulgence produced a dramatically steeper decline in ghrelin after consuming the shake, whereas the mindset of sensibility produced a relatively flat ghrelin response. Participants’ satiety was consistent with what they believed they were consuming rather than the actual nutritional value of what they consumed.

What should we make of the finding (besides a continued fascination with the placebo effect)? For one thing, it reinforces the notion that our stomachs are very crude sense organs which aren’t precise or accurate at judging how much food they need.

For anyone trying to achieve (or maintain) a healthy weight, the dynamic makes it tougher to diet. The conscious decision to eat ‘sensible’ food motivates our bodies to demand more calories. What a frustrating situation!

Patrick at Discoblog toys with a creative solution:

It definitely suggests some new approaches to dieting, like berating yourself for eating celery sticks in an effort to make them seem more luxurious and satisfying. But it’s not clear if lying to yourself is as effective as having other people lie to you. And believing that you are constantly eating poorly might have other psychological side effects, one supposes.

I agree, it probably doesn’t work as well to lie to yourself (and nobody will be able to convince me that celery sticks are fatty treats). But we can draw a useful tactic that doesn’t require deception. Instead of applying the study’s findings when we eat light food, keep it in mind when eating dessert. Next time you want a rich slice of cheesecake, look up how many calories it has! According to the study, focusing on the fact that the slice has 50% of your recommended calories will make you feel more satisfied eating less of it.

What I’d like to see is a study that’s honest about the number of calories but emphasizes different ingredients to foster that ‘indulgent’ mindset. Would our bodies react differently to drinking a “300-calorie fruit milkshake” compared to the same one described as a “300-calorie shake with bananas, heavy cream, vanilla extract, and pure cane juice”?

If that works, we can help our friends and families by focusing attention on the fattiest, sweetest, and tastiest part of a dish. Next time Julia is willing to make those delicious-looking blintzes again, sign me up. I can eat one as she tells me about the heavy cream that went into the homemade ricotta.

[UPDATE] I’m looking a little deeper into what exactly was being measured – the abstract and researchers said “Participants’ satiety was consistent with what they believed they were consuming rather than the actual nutritional value of what they consumed.” but news sources report this as well:

The study also didn’t find that the larger drop in ghrelin in those who drank the indulgent shakes was accompanied by a larger drop in hunger levels, a finding that the researchers couldn’t fully explain. “We may not have used a reliable measure of hunger,” says Crum. “My sense is that hunger levels should have changed.”

I had assumed that the participants’ satiety was the same as their remaining hunger – but those two quotes seem at odds at first glance.

11 Responses to Why Imagined Indulgence Helps Us Diet

  1. Andrew T says:

    Interesting result. I wonder what the effect of this tendency would’ve been (or if it would be seen at all) before the advent of food science.
    – Before modern transportation, diets were simpler and defined by the food grown locally, so the idea of “indulgence” would probably be related to rarity rather than health effects – would this have the same result, or does the mindset need to pertain specifically to health to affect hunger?
    – I don’t know when the link between sugar/fat and expanding waistlines became conscious knowledge (perhaps there were too many lifestyle factors for it to be noticed by most people until recent centuries). At any rate, a person *before* that time would still be aware of sugar and fat in food, since these are things you can taste to some degree, and might have an instinctive feeling for how that affects their energy after a meal. So I would be curious if you told such a person that a meal was cooked with more sugar, if they would feel fuller afterward. (Assuming, of course, it’s even possible to lie well enough about a property so closely tied to actual taste in the subject’s mind.)

    My point is to discern between the effects of “knowing a food has calories” and “knowing a correlated fact about the food”. Which part of that knowledge is the “real” source of the effect? It just seems odd to me that we have such a dramatic biological response to such a new intellectual concept as calories.

    Also, I’d be interested to know how the ghrelin levels compare between giving a 380 cal shake claimed to be 620 cal, an 620 cal shake told to be 620 cal, and a 620 cal shake with no information given.

    • Jesse Galef says:

      Andrew – agreed, that would be a cool study!

      I get the sense that the ghrelin reaction this study found was all about the perception that the shakes would be satisfying – indulgent in the sense of satisfying, not just luxurious (like a rare fruit). Low-calorie shakes (and diet foods in general) have a reputation for not being very filling, so thinking you’re not going to be satisfied makes you less satisfied.

      My point is to discern between the effects of “knowing a food has calories” and “knowing a correlated fact about the food”. Which part of that knowledge is the “real” source of the effect? It just seems odd to me that we have such a dramatic biological response to such a new intellectual concept as calories.

      Absolutely. That’s why I want to experiment by describing milkshakes differently but leaving the calorie count the same. Calorie count clearly isn’t the only information we take into account when forming expectations about our food, and it might not be the most important.

      That said, it’s nice to think that rational, reality-driven conscious thoughts – the scientific knowledge of how many calories a food has – can have such an impact.

  2. harmamae says:

    I’d guess lying to yourself would have some effect, since apparently you can convince yourself of things that you know aren’t true, but the effect probably isn’t as great as if someone else lied to you.

    • Jesse Galef says:

      Actually, I had originally written more in this post scoffing at the idea of self-deception, but on second thought I decided against it. There probably is some impact of conscious efforts to view food differently, though perhaps not all the way to believing celery is fatty.

      Phrases like “convince yourself of things that you know aren’t true” are tricky, because they go against many common conceptions of how we use the words “know” or “convince”. But there’s definitely something to self-deception – a topic I want to learn more about!

  3. Eugene says:

    This is Eugene. Hey Julia and Jesse!

    This study is close to useless. Mainly because it focuses on extremely short term effects. Our stomachs are indeed crude, but not our brains. The brain over long term is actually incredibly good at controlling caloric intake through hunger if the hormone system is functioning properly.

    I am sure it is possible to full the brain into being more full from one meal. The chances of it being true after weeks of eating these milkshakes are almost 0. Ghrelin while responsible for satiety (in part) plays a very insignificant role in hunger modulation over long term.

    I would be very careful posting nutrition articles to the public without extensive knowledge of nutrition. It is insanely easy to get it wrong. Nutrition is a minefield.

    • Jesse Galef says:

      Hi Eugene!

      I’m actually really interested in nutrition, so if you have specific links and recommendations you think are worth reading, I’d love to hear your suggestions. (Be warned, however, that the spam filter is highly suspicious of comments with multiple links – I’ll keep an eye on it.)

      The brain over long term is actually incredibly good at controlling caloric intake through hunger if the hormone system is functioning properly.

      Really? I’m surprised to hear that, because I’ve read about a number of studies indicating that how much we eat is influenced by a huge host of irrational factors (factors not related to how many calories we’ve taken in vs how many we need).

      I assume this is one of the reasons we have such an obesity problem – our brains simply aren’t doing a good enough job of controlling calorie intake in the long term – telling us how hungry to be, how satisfied to feel while (and after) taking in calories, and what to crave next.

      It’s interesting to know that mind-set (belief that we’re eating something high-calorie) can impact the chemical that gives us those cravings in the short term. I agree, a long-term study would be cool, to see if the body corrects later. I’m just skeptical that our hormone system works quite so well.

      • Eugene says:

        Hey Jesse, I appreciate that you didn’t get defensive about what I said.

        I can defiantly point you to quite a bit of resources I found to be the best after reading on this topic for years. Although I myself don’t remember why I made my conclusions due to sheer amount of studies, terminology, and time that passed.

        Should I email you? Or post them here?

  4. Eugene says:

    Also the idea that sensible foods cause the body to require more calories is contradicted by almost every longer term study. I am not sure where the conclusion is coming from.

  5. Eugene says:

    I mean to begin with this study is comparing milkshake with milkshake not milkshake and broccoli.

  6. Max says:

    I think if a person has a habit of eating a lot of calories, then the thought of a light meal may leave him craving for more, but if he develops a habit of eating light meals, then that becomes the new norm.

  7. Howard KI. says:

    A friend sent me the link to this site, and I am delighted to see these posts and ideas. They are all great–lots of stuff to think about, and very intelligently done.

    I do have one request: I rarely watch videos or listen to audio for information. I can’t print out either, and it takes far less time to read material than to watch or listen. So if there is any way to get the audio of some of these discussions in print, as a xscript, that would be wonderful.

    And Galefs, how do we contact you by email?

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