Research Review: Imagine more, crave less? | Precision Nutrition

Research Review: Imagine more, crave less?

By Helen Kollias

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Cravings are a funny thing. Out of the blue you suddenly need to eat X. You could try eating something else but it’s just not the same.

I’ve heard experts say that if you resist your craving for 15 minutes it will go away.

Fifteen minutes? Oh please. I’ve had cravings go on for days.

The “wait it out” method doesn’t seem to work for me.

Other strategies are to have a little of whatever you crave. For many people, that little bit tends to become a lot.

Looks like we need a new plan.

Luckily, research marches on! New studies suggest that you can curb your appetite and cravings through imagined eating.

Yup, you sit down and imagine eating a lot of the food you crave. Not a bite or two — I mean imagining bite after bite of the food you crave… without actually eating anything.

Sounds like a recipe for disaster, or at the very least a not-so-imaginary binge on your craving, doesn’t it? Stay with me and read on.

Does daydreaming about food change how much we eat?

On the subject of whether thinking about food helps you stop eating, experts fall into two camps.

Camp 1: Don’t think about food

One camp believes that thinking about yummy food increases how much you want the yummy food. Thus, if you’re trying to eat less, don’t think about yummy food. (I know you’re thinking of yummy food right now. Big Brother is watching, so stop.)

For example, if you think about a yummy spinach salad, how it looks, tastes, and feels in your mouth, your body gets ready to eat by increasing saliva production.

If no spinach is actually eaten, then you really want to get some spinach salad. If you do get your hands on that spinach salad, look out — there’s gonna be a spinach blowout.

Camp 2: Think about food more

The other camp believes that thinking about eating yummy food will make you sick of it and you will eat less in the real world.

Thus, they say, you should think about yummy food before you eat it. This idea is based on two things:

  • perception and mental imagery are closer to each other than we think; and
  • we become used to and then bored of (aka habituated to) food.

For example, in the first case, clearly imagining a spider crawling across your leg will give you the same racing heart, creepy feeling, and cold sweats that an actual spider crawling across your leg would give you (1).

Yes Neo, thinking you are eating spinach salad gives you a very similar response to actually eating it in the real world.

Wait! Aren’t both ideas the same? Aren’t both camps saying that thinking about eating is almost the same as actually eating it?

Yes, but the difference between the two camps comes down to habituation — that is, after being repeatedly exposed to a stimulus, be it food or violence on TV, you have less of a response (you habituate).

Your brain loves novelty. If it habituates, it starts looking elsewhere for entertainment. (This is one reason why all-you-can-eat buffets can be so dangerous — to your brain, buffet equals novelty-fest and you never habituate enough to quit eating. You have to be forced to quit by your stomach threatening to explode.)

Thus, it’s not enough to think about eating spinach salad. In order become habituated, you need to think (in detail) about eating a lot of spinach salad. You have to imagine eating enough to get bored of it.

Imagining eating one or two bites of your favorite indulgences makes you want to eat more, but imagining eating 30 or 50 bites of your favorite indulgence makes you want to eat less of that specific food (2).

Research question

This week’s review asks: Does the thought of eating food makes you eat less real food?

Morewedge CK, Huh YE, Vosgerau J. Thought for food: imagined consumption reduces actual consumption. Science. 2010 Dec 10;330(6010):1530-3.

Methods

This study examines a series of separate experiments that involved people imagining eating M&Ms, eating cheese, or using coins, then seeing how much M&Ms or cheese they ate. (No control group looked at them eating coins, although rumour has it that one lab assistant’s two-year-old attempted it.)

Experiment #1 – Does thinking about eating M&Ms change the amount of M&Ms eaten?

Participants were asked to imagine one of the following scenarios:

  1. putting 33 coins into a laundry machine (0 M&Ms);
  2. eating 3 M&Ms and putting 30 coins into a laundry machine (3 M&Ms); and
  3. eating 30 M&Ms and putting 3 coins into the machine (30 M&Ms).

After imagining, all participants were asked to take a M&M taste test, in which they could eat as many M&Ms as they wanted from a 40 g bowl and rate how yummy the M&Ms were. All participants randomly did all 3 scenarios.

Experiment #2 – Does imagining coins change the amount of M&Ms eaten?

Experiment #2 was similar to experiment #1, but this time, the imaginary act of eating M&Ms was separated from the imaginary act of putting coins in a washer (i.e. not eating).

Here, researchers wanted to make sure that the act of imagining itself (regardless of what was imagined) wasn’t the important factor.

Participants (51 participants) were asked to imagine four scenarios:

  1. eating 3 M&Ms;
  2. eating 30 M&Ms;
  3. putting 30 coins in a laundry machine; and
  4. putting 3 coins in a laundry machine.

After imagining, they took the M&M taste test and how much they ate was measured.

Experiment #3 – Does imagining moving around M&Ms change the amount of M&Ms eaten?

The participants imagined either putting 3 or 30 M&Ms into a bowl, or eating 3 or 30 M&Ms. Then they did the M&M taste test.

Here, the researchers wanted to see whether it was important that participants imagined eating, rather than doing other things, with the M&Ms.

Experiment #4 – Does the type of food you imagine change how much you eat?

Participants either imagined eating 3 or 30 pieces of cheese, or 3 or 30 M&Ms. Then they got to taste cheese.

Here, the researchers wanted to see whether imagining other kinds of foods (i.e. not M&Ms) affected future M&M consumption.

Results

Experiment #1 – Does thinking about eating M&Ms change the amount of M&Ms eaten?

Yes. But in order for this to work, people had to eat a fair number of M&Ms, not just a few.

Figure 1 below shows that when people were asked to imagine eating 30 M&Ms, they ended up eating fewer real M&Ms during the taste test (about half), compared to people who didn’t eat any imaginary M&Ms, or just 3 fictitious M&Ms.

Cool.

Figure 1: Actual vs imaginary M&M consumption

Experiment #2 – Does imagining coins decrease the amount of M&Ms eaten?

No.

Simply imagining manipulating coins didn’t decrease real M&M eating (see figure 2).

Figure 2: Imaginary M&Ms eaten vs imaginary quarters moved

Experiment #3 – Does imagining moving around M&Ms decrease the amount of M&Ms eaten?

No.

Just like you have to imagine the food in Experiment #2, you also have to imagine actually eating the food. In fact, imagining the food without imagining eating it can lead to higher consumption.

Figure 3: Imaginary M&Ms eaten vs imaginary M&Ms moved

Experiment #4 – Does the type of food you imagine change how much you eat?

The last two experiments make it pretty clear that pretending to eat the M&Ms was key. Neither imagining other things nor imagining moving M&Ms around helped.

In this experiment the researchers wanted to know if imagining eating one food would make you eat less of other foods. In this case, researchers used imaginary cheese cubes or imaginary M&Ms, then compared this to eating real cheese cubes.

Figure 4 shows that not only do you need to think about imaginary eating in general, but also the particular imaginary food to avoid eating the real thing. Thus, if you are trying not to eat cheese, you need to imagine eating 30 cubes of cheese. 30 imaginary M&Ms won’t work.

Figure 4: Imaginary M&Ms eaten vs imaginary cheese cubes eaten

Conclusion

  1. More imagined food means less real food: Imagining eating a lot of a food (30 M&Ms) leads to eating less food in reality.
  2. Only imaginary eating works to reduce real life consumption. You have to imagine eating to lessen your real life eating. Imagining doing other things doesn’t work.
  3. Imaginary eating is food specific. Eating imaginary food only lessens your appetite for that food in real life. If you imagine eating Twinkies it wouldn’t protect you from, say, chocolate.

There are a few things still left to be sorted out, including:

  • How long does your food imagination reduce your real-life eating?
  • Does this work if I know what’s going on? In the experiments the participants weren’t told that eating imaginary M&Ms may lead to them eating fewer M&Ms.
  • Does this work for addictive substances like coffee and alcohol?

An argument for mindfulness

If you think about this idea that perception is reality, it supports the idea of mindful eating.

If you are actually eating, but are not perceiving it (not paying attention), then as far as your brain is concerned you haven’t eaten any imaginary M&Ms, so you haven’t lessened your appetite (no habituation). Sure, you have physical cues from your stomach stretching or nutrients digesting, but those are notoriously slow and when you don’t pay attention when you eat, you generally eat faster.

Fast unperceived eating is a double whammy, because you bypass the part of your brain that get habituated to the taste/feel etc. of that food, making it less appetizing. You end up stuffing yourself with more before your body and brain realize you should stop.

Bottom line

There are still unanswered questions about this, but it seems that imagining eating foods makes you eat less of those particular foods when you have a real chance to eat them. In order for this to work:

  • Imagine eating enough — until the imagined food is less appealing (sort of like counting sheep till you fall asleep).
  • Imagine the specific food you are trying not to eat.

Next time you have a craving, give this a try. See if it works!

References

Click here to view the information sources referenced in this article.

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