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Always Hungry? Blame It On Food Porn



sharma-obesity-fmri-brain1There is no doubt that living in a society in which we are constantly surrounded by highly palatable foods makes not overeating a challenge for most of us.

Now, an interesting paper by Charles Spence and colleagues from Oxford University, published in Brain and Cognition, makes a strong case for how exposure to images of desirable foods (which they label ‘food porn’, or ‘gastroporn’) via digital interfaces might be inadvertently exacerbating our desire for food (what they call ‘visual hunger’).

In their paper, the authors review the growing body of cognitive neuroscience research demonstrating the profound effect that viewing such images can have on neural activity, physiological and psychological responses, and visual attention, especially in the ‘hungry’ brain.

Beginning with a brief discussion of evolutionary aspects of vision and food, the authors remind us that,

“Foraging – the search for nutritious foods – is one of the brain’s most important functions. In humans, this activity relies primarily on vision, especially when it comes to finding those foods that we are already familiar with. In fact, it has been suggested that trichromatic colour vision may originally have developed in primates as an adaptation that facilitated the selection of more energy-rich (and likely red) fruits from in-amongst the dark green forest canopy.”

“The brain is the body’s most energy-consuming organ, accounting for somewhere in the region of 25% of blood flow, or rather, 25% of the available consumed energy. Note that this figure is even higher in the newborn human, where the brain absorbs up to two thirds of the energy that is consumed by the developing organism. As Brown notes: “In embryos, the first part of the neocortex to develop is the part which will represent the mouth and tongue…” As the brain grew in size over the course of human evolution, the demands on the visual system to efficiently locate nutrients in the environment would likely also have increased.”

This notion is not trivial given our current environmental exposure to a multitude of food images:

“Our brains learnt to enjoy seeing food, since it would likely precede consumption. The automatic reward associated with the sight of food likely meant another day of sufficient nutrients for survival, and at the same time, the physiological responses would prepare our bodies to receive that food. Our suggestion here is that the regular exposure to virtual foods nowadays, and the array of neural, physiological, and behavioural responses linked to it, might be exacerbating our physiological hunger way too often. Such visual hunger is presumably also part of the reason why various food media have become increasingly successful in this, the digital age.”

And the influence of food media is widespread:

“Every day, it feels as though we are being exposed to ever more appetizing (and typically high calorie) images of food, what some (perhaps pejoratively) call ‘gastroporn’ or ‘food porn’. Moreover, the shelves of the bookstores are increasingly sagging under the weight of all those cookbooks filled with high-definition and digitally-enhanced food images. It has been suggested that those of us currently living in the Western world are watching more cookery shows on TV than ever before. Such food shows often glamorize food without necessarily telling a balanced story when it comes to the societal, health, and environmental consequences of excess consumption.”

And let’s not forget facebook and Instagram:

“At the same time, the last few years have seen a dramatic rise in the dining public’s obsession with taking images of the foods that they are about to eat, often sharing those images via their social media networks. The situation has reached the point now that some chefs are considering whether to limit, or even, on occasion, to ban their customers from taking photographs of the dishes when they emerge from the kitchen. However, one restaurant consultant and publisher has recently suggested that the way food looks is perhaps more important than ever: “I’m sure some restaurants are preparing food now that is going to look good on Instagram”.

The paper goes on to discuss at length the evidence that exposure to images of foods can alter cognitive responses and create the need for constant dietary restraint, which may be more difficult for some than others.

But not all images of food have these effects:

These results support the view that people rapidly process (i.e. within a few hundred milliseconds) the fat/carbohydrate/energy value or, perhaps more generally, the pleasantness of food. Potentially as a result of high fat/high carbohydrate food items being more pleasant and thus having a higher incentive value, it seems as though seeing these foods results in a response readiness, or an overall alerting effect, in the human brain.

As for the parts of the brain that are stimulated by exposure to food images – pretty much all of it. Thus, in one study:

“…the results revealed that obese individuals exhibited a greater increase in neural activation in response to food as compared to non-food images, especially for high-calorie foods, in those brain regions that are associated with reward processing (e.g., the insula and OFC), reinforcement and adaptive learning (the amygdala, putamen, and OFC), emotional processing (the insula, amygdala, and cingulate gyrus), recollective and working memory (the amygdala, hippocampus, thalamus, posterior cingulate cortex, and caudate), executive functioning (the prefrontal cortex (PFC), caudate, and cingulate gyrus), decision making (the OFC, PFC, and thalamus), visual processing (the thalamus and fusiform gyrus), and motor learning and coordination, such as hand-to-mouth movements and swallowing (the insula, putamen, thalamus, and caudate).”

But this knowledge is not all bad. There is also some evidence that digital manipulation of images of vegetables and other healthy foods can make them more attractive and thus hopefully increase their consumption. Whether or not this would actually work in practice remains to be seen.

Nevertheless,

“Given the essential role that food plays in helping us to live long and healthy lives, one of the key challenges outlined here concerns the extent to which our food-seeking sensory systems/biology, which evolved in pre-technological and food-scarce environments, are capable of adapting to a rapidly-changing (sometimes abundant) food landscape, in which technology plays a crucial role in informing our (conscious and automatic) decisions.”

Are you affected by exposure to foodporn? Is this really a problem?

@DrSharma
Edmonton, AM

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7 Comments

  1. This is an interesting study. As you may recall, I have mixed feelings about the NWCR. I stay on the registry because I accrue personal value in the “accountability” function of having to reveal changes in my weight year to year. (In other words, the measuring affects the result. A common issue in research, but helpful to me, given that I want that effect.) Moreover, the core research of the NWCR is survey-based and sight unseen (on line, linked by email), which makes it more unreliable. (No one would lie about their weight on a blind survey, now, would they?)

    That said, some researchers at the NWCR did do ONE empirical study. (Hooray!) They took people from the registry and stuck their heads in a fMRI machine and showed them food porn. Since these participants had to show up for the fMRI, we know they aren’t among the survey liars. They are for real maintainers. And what the NWCR found was that they don’t respond to food porn the way common people (non-weight reduced) do. They didn’t fly me out, but this resonates with me. I know the rest of my family and I can be watching a fast food ad together, and they’re going “Oooooh!” and I’m going “Kaaaach!” to the same images.

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    • Brown and Wing (principles in the NWCR) published a great 2007 article demonstrating using FMRI that NWCR cohort has higher levels of restraint evidenced by activation of the restraints centre in brain (dorsolateral prefrontal cortex)compared to non -dieters obese subject.

      demonstrating nicely that restraint according to them is the key behavioural attribute in those who lose weight and keep it off.

      study –> Successful dieters have increased neural activity in
      cortical areas involved in the control of behavior
      international journal of obesity

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      • Yes, Dr. M, your recall of the study is accurate. In terms of “control,” (and who knows if this made a difference or if I’m just fortunate in other ways) when I was in my weight-loss phase (before a maintenance counter-reaction in my hormones, gut peptides, etc., had an opportunity to set in), I purposefully would concentrate on creating negative reactions to high-density foods, especially over-the-top large portions and overly sugared foods. I pronounced the word sugar with a kind of lispy “S” to make it sound ickier, and I shudder physically as I said it. I would see a double or triple burger and mentally or verbally say, “Gross!” Over time, I applied these negative reactions to smaller and smaller portions, to closed-face sandwiches (who needs a second piece of bread?) and knocked most of the added sugar completely out of my diet.

        Did I reprogram my dorsolateral prefrontal cortex? Who knows? Did the thinking process border on disordered? Who’s to say? I did it. I’m a for-real (unicorn) maintainer now. It’s still hard, but probably not AS hard since big food grosses me out to this day.

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        • Sounds like a classical case of neuro-linguistic programming to me – glad it worked for you…

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          • As I think about it Dr. S, this is one of the “healthy” things I did in terms of approaching weight loss/maintenance. I had yo-yoed twice before (and blamed myself, of course), but this last time, I reviewed the empirical research on maintenance in my loss and early maintenance time, and that served as a wake up call. 3% success in long-term significant maintenance from behavior-based losses, essentially, is what I concluded. After a big “Oh, Sh*t!” I became a science junkie and thought up ways to apply those studies that resonated with me, and I rejected a bunch of the stuff that didn’t “take” before (but some scientists and women’s magazines claimed was useful). Exercise buddies, for example — stupid idea. You don’t motivate each other for the long haul. When one person slowly poops out (and always that happens), the other goes too, if only to not make the other feel bad.

            Reprogramming my brain to gross out at big food and spshugar (with a shudder). That was good. I can think of another oddball thing I did that was significant, but it’s too lengthy to go into now. Anyway, thanks for giving me a way to justify, classically, what I’m doing, at least to some degree.

  2. Very, very interesting! I wonder who isn’t touched by food porn? I’ll admit I so much prefer salty and fatty food porn, is that a prehistoric trait?
    I’d like to know, in your huge expertise Dr. Sharma, what do you think is a recommend balance of neural stimuli in these times (and the ones that are coming)? Is it more on the path towards reduced stimulus (like meditation, staying away from TV perhaps?), or increasing other counteracting non-food-related stimuli (which ones do you think are healthy ones?)?
    Thank you for your stimulating insights!

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    • Not sure – being aware of the effects that these images may have is a first step – obviously, we can all contribute to reducing this foodporn pollution by not Instagramming, facebooking or tweeting every meal we take.

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