Research Shows Chefs Can Use Sight, Sound & Smell To Help Us Eat More Sustainably

Behavorial scientist Dr. Sophie Attwood highlights the many ways we can use sight, sound and smell to nudge us to make better food choices and how chefs and foodservice operators can use these insights to help trigger more planet-friendly eating.

Your plate arrives. The delicious aroma wafts towards you before you even see the dish. Your mouth waters.  

Placed down, your eyes absorb the portion in front of you, the blend of colors, and quality of ingredients. You sense the heat from the plate, hear the sizzle of food, and your stomach gurgles in anticipation. 

No question that the sight of a tasty meal can kick-start our appetite. This fact is well exploited by food marketers who successfully promote products with compelling food photographs all the time – large, hyper-colored images of juicy burgers, oozing with sauce, or oven-crisp golden pizza with melting cheese.  

Knowing exactly when and how to use such images is not only beneficial for food businesses hoping to boost profit by making us hungry, but is also a hugely under-leveraged technique that could be used far more extensively by those working to promote more sustainable diets worldwide. 

Our food system contributes around one-third of global greenhouse gas emissions, with meat and dairy products having an outsized negative impact on the environment. Indeed, recent research suggests that emissions from food alone will likely prevent global temperature rises from staying within the ‘safe operating space’ of <2°C, as defined under the Paris Agreement. As a result, far deeper and more widespread changes to our collective diets are urgently needed. In particular, eating more resource-efficient, plant-rich foods and fewer animal-based products.  

A simple goal to state, but one that is much harder to achieve in practice. 

Non-conscious priming plays a valuable role in triggering our food choices

It is here that non-conscious, sensory ‘primes’, such as compelling food images, can play a valuable role. Priming refers to the act of exposing someone to a cue (or ‘stimulus’) that predisposes them towards a subsequent object (or ‘target’). This association happens automatically and below our conscious awareness.  

Images work incredibly well as food choice primes, as do indulgent, taste-focussed menu descriptions. Both techniques trigger us to simulate eating in our imaginations, so whetting our appetites, and have been proven to motivate diners to select more plant-rich meals. 

Less well-known, however, is the effect of a broader array of other sensory primes that target sight, as well as smell and sound, to encourage people to select lower-emitting foods. Touch and taste are, of course, relevant, but seemingly more important post- rather than pre-choice, where taste, texture and mouthfeel will all determine the likelihood of repeat food purchases. 

In lieu of a body of consistent research exploring how sensory primes can be best deployed to promote sustainable diets, we can instead draw upon existing work exploring how these techniques influence food choice more generally.  This insight can inspire some tentative suggestions on how our senses can be more actively targeted in food retail and service to prompt more people to eschew meat and choose plants on a regular basis.

From food shapes to presentation arrangements to menu typefaces, sight matters

When it comes viewing written words, it’s not only the content that seems to matter for food choice, but something as seemingly unimportant as a typeface can also prove highly influential. Inherently, it seems, we associate differently shaped food with distinct taste profiles, with roundness linked to sweeter tastes and angular items evoking sourness or spice. Research on this phenomenon has demonstrated a clear ‘congruence effect’, whereby consumers report more favorable attitudes, and greater intentions to purchase, round-shaped foods described on menus using rounded font, and angular foods presented in angular font. 

While no research has explicitly studied the role of typefaces in promoting sustainable options, it would follow that matching typefaces to taste expectations, such as identifying fonts that evoke the ideas of freshness or fillingness of plant-rich meals, could be used as a potentially effective promotional tool.  

Modifying the overall appearance of a dish has been more extensively researched in the context of sustainable diets, with proven approaches including blending plant proteins into meat dishes or compensating for meat reductions by adding plant-rich sides and garnishes. In general, these types of stealth changes are rarely noticed by diners, and meal satisfaction tends to remain unaffected. 

The influence of dish presentation can go further than this, however, with diners also apparently sensitive to more aesthetic visual aspects. For example, one new study reveals that diners prefer, and are even willing to pay more for, dishes with ingredients arranged in an upwards-facing triangle directed away from them, rather than downwards and pointing towards them. Authors suggest this may be because the latter presentation is interpreted as aggressive, given a common implicit association between angular shapes and threat. 

Related to this, further research has looked into the role of ingredient orientation in food choice, finding that diners perceive portion sizes as larger, and are once again willing to pay more for a meal, when the same ingredients are spread horizontally and placed centrally in a dish, rather than stacked vertically or at a central offset.

The color and balance of ingredients matter, too, and appear to interact in unique ways.  In general, balanced and even presentations of ingredients are considered more attractive, with research finding that the appeal of a balanced dish can be boosted if color is added to the mix. Contrary to this, however, adding the same colors to more messy and unbalanced dishes seems to have the opposite effect.  

One other new study has directly demonstrated that color can influence decisions to consume plant-rich meals. In this trial, diners were more likely to opt for vegetarian options when meat-heavy meals were present on red-colored tables, rather than on green ones, in part because the red background decreased the visual attractiveness of the meat.  

Together, these findings offer guidance for chefs and culinary creators, suggesting balanced and harmonic presentations of plant-rich ingredients is key. Far more research is needed to understand exactly how different visual elements in a dish can be modified to promote plant-rich options, and particularly, how color can be better used to encourage more sustainable choices, moving beyond the commonly held assumption that green is always good. 

How sound enhances eating experiences

Beyond our eyes, our ears have an important, yet chronically under-exploited influence on our perceptions of food. Congruence again plays a role here, with sounds that match taste expectations (i.e. a rustle of a crisp packet, crunchy white noise with fresh crudité) shown to enhance eating experiences. 

One other possible explanation for the effect of sound on food choice focuses on the role of cross-transference between physiological arousal, emotions and taste perceptions. For example, louder, stressful industrial noises have been linked to more negative eating experiences compared to softer, more soothing natural sounds, while heightened sweet and pleasant tastes are observed when food is consumed to natural soundtracks, and higher bitterness is found with machine noises.

Interestingly, natural sounds (i.e. waves, bird songs) and calming music have both been associated with a greater liking of plant-based items, including fruit and vegetables. This is possibly due to the music’s relaxing effect, which has been postulated to help us avoid cognitive depletion and support more reflective, value-driven choices. 

If applied within restaurants, cafes and canteens, we can hypothesize that more sustainable plant-rich food choices will follow from the introduction of relaxing soundscapes, whether through the congruence effect or via a boost to our self-control. As a cheap, easy and unobtrusive intervention, little will be lost from more widespread experimentation with different soundscapes in food service and retail settings, to determine which proves most valuable in eliciting a switch from animal to plant-rich options.

Smell: a powerful influence on food selection

Smell is one of the most potent of our senses and is critical to our experience of food. In terms of choice, new research again demonstrates a congruence effect, finding that peoples’ eyes go first to those menu items whose taste (i.e. sweet or savoury) matches that of a surrounding odour. Other emerging work indicates that smell may prove to be a more powerful influence on food selection than sight, even, boosting desire to a greater extent when wafted towards hungry diners in a highly motivated and receptive state. 

Before we can deploy smell to effectively promote more sustainable meals, we need more research to identify which odours work best to promote plant-rich dishes, and when to expose people to these for maximum impact. This research would be well supported by an additional body of work exploring optimal mixtures of different sensory primes, helping us to better understand possible synergies between smell, sight and sound, and how to boost impact by pairing complementary approaches together.  

Sensory primes on food choices are an important tool for sustainable diet nudging

Overall, the significant influence of non-conscious, sensory primes on food choice has been consistently proven across a body of compelling research, yet hardly explored in the context of promoting more sustainable diets. Right now, this represents an important missed opportunity and a new horizon for environmentally-minded culinarians and sustainability advocates who can work to better pique our senses, rather than just appeal to our better selves, to create the dietary shift that we so urgently need.