So What If We Eat First With Our Eyes?

It was Apicius, the Roman gourmand who, long ago, purportedly coined the phrase “We eat first with our eyes.”¹ The latest evidence from the emerging field of gastrophysics – that is, the study of gastronomy combined with psychophysics (the measurement arm of psychology’s perception science)² – is increasingly supporting his assertion.

For instance, neuroimaging evidence shows that there is nothing that gets our brains quite as excited as the sight of our favorite meal when we are hungry, leading to a 24% increase in cerebral blood flow in one study³. No wonder they call all those beautiful plates of food on Instagram “food porn”/”gastroporn.”

Much of the research interest in the science of plating in recent years has been focused on trying to make the food look as attractive and/or plentiful as possible. As an example of the former, Franco-Colombian chef (and recent contestant on Netflix’s The Final Table cooking show) created a salad based on Kandinsky’s “Painting number 201” hanging in the Museum of Modern Art in New York; see Figure 1)⁴. Together, we conducted a series of experiments here in the Crossmodal Research Laboratory in Oxford, but also in the dining room of Somerville College, Oxford in order to assess how diners would respond to food that looks beautiful/artistic. No surprise for guessing that diners were willing to pay significantly more (more than double in one study) for the aesthetically-appealing plating than for the tossed version of exactly the same ingredients. 

But can the diner’s eyes, or rather their brain, really be tricked into thinking (and more importantly feeling) that there is more food on the plate than is actually the case? This was the aim behind one of the latest studies published by Oxford University’s Crossmodal Research Laboratory. Together with Masters student Jessica Rowley, we conducted study, published in the journal Appetite⁵, showing that how the food is arranged on the plate (stacked vs. spread out) exerts a profound influence over how much food there appears to be (and, more importantly how much people reported being willing to pay for the dish; see Figure 2).

As is often the way these days, we first conducted an internet-based study in order to assess the impact of plating (either spreading the various elements out on the plate or stacking them up vertically; see Figure 2) on people’s rating of how much food they thought there was. In this case, our participants (N = 122) did not get to taste anything, only look at a picture and rate what they saw. Nevertheless, the results clearly showed that people estimated there to be 64% more food when the elements were spread out across the plate than when exactly the same components were stacked up instead. What is more, when asked to estimate how much they would be willing to pay for the dish, price estimates for the spread arrangement were more than 60% higher than when the same elements were stacked up, too.

Having demonstrated the basic idea that visual appearance matters, we then went on to conduct a follow-up study in a dining room of one of the Oxford colleges. In this case, 124 diners, namely those attending one of the regular college guest nights, were either served a stacked or spread arrangement of the same ingredients. They were required to rate the dish that they had been served both prior to tasting and after having finished the dish. Once again, the results clearly demonstrated that spreading out the food elements in the center of the plate led to people rating there to be more food than with the stacked asymmetrically-plated arrangement. Perhaps more importantly (at least for any restaurateurs out there), our diners once again reported that they would have been willing to pay significantly more for the dish too.

These results are consistent with those from another series of studies in which we tested the kitchen folklore suggesting that chefs should plate odd rather than even numbers of elements on the plate. At the Science Museum in London (as part of the Cravings Exhibition), and in a series of follow-up online experiments, we showed people two plates of seared scallops side-by-side (see Figure 3). The simple question that people had to respond to is which plate they preferred (i.e., to be served/to eat). All that we varied was whether the plates had an odd or even number of scallops on the plate. The results of a series of seven experiments testing the preferences of several thousand participants showed that people didn’t show any preference for odd vs. even numbers on the plate, but systematically chose as preferred the plate that displayed a greater amount of food!⁶

While such results are impressive in their own right, they do issue a challenge as far as the display of food on product packaging is concerned. There, the evidence suggests that the average portions shown on product packaging are actually up to three times the recommended portion size⁷. The danger is that this sets inappropriate consumption norms for consumers. Just imagine yourself at the breakfast table thinking about how much cereal to serve yourself while staring at the front of the pack of cereal (see Figure 4). Now, of course, the marketers want to make the food images on the product packaging as appealing (i.e., as filling) as possible, so that more consumers will buy it. Hence, there is something of a conflict/tension between the desires of marketing (potentially setting inappropriate consumption norms in their search for ever-increasing sales) and the aspirations of those interested in a little behavioral economics “nudging” to get us all to eat a little less.

In our latest research, we provide a potential solution to help alleviate this tension/problem: Namely, we used the Delbouef illusion (see Figure 4), to give the visual impression of there being more food (by varying the width of the rim of the bowl of cereals), while at the same time showing that action (namely how much cereal people served themselves) was unaffected by the visual illusion⁸. Should such findings be replicated⁹, they might well offer an intriguing means by which a visual illusion can be used to help bias purchase behavior, while at the same time hopefully helping to avoid overconsumption.

Taken together, therefore, the latest gastrophysics research clearly shows why we should all care about the fact that we eat first with our eyes.

References:

1. Apicius (1936). Cooking and dining in Imperial Rome (c. 1^st Century; translated by J. D. Vehling). University of Chicago Press, Chicago.
2. Spence, C. (2017). Gastrophysics: The new science of eating. London, UK: Viking Penguin.
3. Wang, G.-J., Volkow, N. D., Telang, F., Jayne, M., Ma, J., Rao, M., Zhu, W., Wong, C. T., Pappas, N. R., Geliebter, A., et al. (2004). Exposure to appetitive food stimuli markedly activates the human brain. NeuroImage, 212, 1790-1797.
4. Michel, C., Velasco, C., Gatti, E., & Spence, C. (2014). A taste of Kandinsky: Assessing the influence of the artistic visual presentation of food on the dining experience. Flavour, 3:7; Michel, C., Velasco, C., Fraemohs, P., & Spence, C. (2015). Studying the impact of plating on ratings of the food served in a naturalistic dining context. Appetite, 90, 45-50.
5. Rowley, J., & Spence, C. (2018). Does the visual composition of a dish influence the perception of portion size and hedonic preference? Appetite, 128, 79-86.
6. Woods, A. T., Michel, C., & Spence, C. (2016). Odd versus even: A scientific study of the ‘rules’ of plating. PeerJ, 4:e1526. https://doi.org/10.7717/peerj.1526
7. Tal, A., Niemann, S., & Wansink, B. (2017). Depicted serving size: Cereal packaging pictures exaggerate serving sizes and promote overserving. BMC Public Health, 17(1):169.
8. Petit, O., Velasco, C, & Spence, C. (in press). Are large portions always bad? Using the Delboeuf illusion on food packaging to nudge consumer behaviour. Marketing Letters.
9. Cf. McClain, A., van den Bos, W., Matheson, D., Desai, M., McClure, S. M., & Robinson, T. N. (2014). Visual illusions and plate design. The effects of plate rim widths and rim coloring on perceived food portion size. International Journal of Obesity and Related Metabolic Disorders, 38, 657-662.