How does colour affect the way we eat?

It’s often said that ‘we eat with our eyes’ and science shows this is true – colour plays an important role in how we perceive and experience foods. But how does this happen?

This piece by Caroline Wood was shortlisted for the Colour Group’s Prize for Outstanding Communication in Science. It was originally published on 02 February 2021 on the online platform Food Unfolded: https://www.foodunfolded.com/article/how-does-colour-affect-the-way-we-eat

Colour and taste

All of us subconsciously associate certain colours with distinct tastes and flavours. For most people, red is associated with sweetness, yellow and green with sourness, white with salt, and brown and black with bitterness. “The research shows that even infants only a few months old are already starting to pick up these associations between colour and taste” says Charles Spence, Professor of Experimental Psychology at Oxford University.¹

“I believe that we learn these associations from the statistics of our environment – we quickly learn that sweet foods are more often pink or red, for instance.” Interestingly, in 2009, Professor Spence tested a clear blue drink on participants from the UK and from Taiwan. The Taiwanese thought that the drink would taste of mint, whilst the UK participants thought it would taste of raspberry – showing they had picked up different associations from their distinct food marketplaces.

Colour can override flavour

These strong colour cues can even override the actual flavour of the food. Studies on social drinkers, wine students and wine experts have found that adding an odourless, tasteless red dye to a white wine causes it to be described as a red wine.^2,3 And when our colour cues are completely mixed up or absent, this can throw us into confusion. For instance, limited edition white Skittles (which retained the different flavours despite each being coloured white) had consumers baffled. Meanwhile, modernist chefs are starting to mix up colours to create unusual dining experiences, such as chef Heston Blumenthal’s confusing orange and beetroot jellies.

Using completely unexpected food colours is also a frequent marketing ploy to gain attention and boost sales. These efforts include Burger King Japan’s all-black burgers coloured with bamboo charcoal and squid ink, and a green tomato ketchup launched by Heinz to promote the first Shrek film. “Blue-coloured food and drinks are becoming increasingly popular amongst Instagrammers, bloggers, and food marketers. Because very few foods are naturally blue, these unusual products stand out on the shelf and hence capture our attention –we notice it” says Professor Spence.

Can colour impact how much we eat?

But why are we drawn to unusual colours in food? One of the leading theories is sensory-specific satiety: if our senses constantly receive the same stimulus, we simply get bored. “Even if you love banana milk, for example, as you keep drinking it you will eventually no longer want any more, you have become satiated” says Professor Spence. “We can become satiated to flavours, but also to textures, and even colours. This is why candy-covered chocolates like Smarties come in an array of colours, to keep our interest.” Numerous studies back this up – we generally help ourselves to more of a food product if it comes in a more varied array of colours.⁴ Curiously, one study found that participants consumed more yoghurt when three types were offered compared with one – even when the colour varied but not the flavour.⁵

It appears we also tend to underestimate quantities when a variety of colours are present. In a study where participants were asked to try and pour out M&Ms until they reached a specified amount in a bowl, the participants poured 12% more into a bowl when the sweets were multicoloured, rather than a single colour.⁶ “We propose that a single colour makes the food appear like a single overall large mass whereas varied colours break up this large perceptual mass” says Professor Joe Redden from the University of Minnesota, who led the study. “This suggests that people should be more vigilant when serving themselves varied mixes; more is there than they think.”

It doesn’t even have to be the food!

Various studies have shown that we even respond to colour cues in product packaging, plates and cutlery. In a study on popcorn, participants perceived a salty variety as tasting much sweeter when served out of a red bowl, and a sweet variety as being saltier when served from a white bowl.⁷ Even the colour of the surrounding environment can have an effect: in one experiment, tourists were willing to pay more for a wine when they sampled it under blue or red light compared with green or white lighting.⁸

Food and colour psychology- eating with colour can help dementia patients

Colour psychology is fascinating – but once we know about it, we can also find ways to benefit from it practically. One study found that patients with dementia were encouraged to eat more when their food was served from coloured plates.⁹ “Many people with Alzheimer’s disease and other neurological conditions lose their sensitivity to contrast, so enhancing the contrast between the plate and their food and drink presumably meant they could see it better” says Professor Alice Cronin-Golomb from the Boston University, who helped lead the study. Perhaps we can all experiment with using colour to make meals appear more appealing, particularly through emphasising the colours we associate with our favourite tastes.

References:

1. Reardon, Patricia, and Emily W. Bushnell. Infants’ sensitivity to arbitrary pairings of color and taste. Infant behavior & development (1988).
2. Morrot G, Brochet F, Dubourdieu D. The color of odors. Brain Lang. 2001;79:309–20.
3. Parr, W.V., Geoffrey White, K. and Heatherbell, D.A., 2003. The nose knows: Influence of colour on perception of wine aroma. Journal of Wine Research, 14(2-3), pp.79-101.
4. Kahn, Barbara E., and Brian Wansink. The influence of assortment structure on perceived variety and consumption quantities. Journal of consumer research 30.4 (2004): 519-533.
5. Rolls, Barbara J., E. A. Rowe, and E. T. Rolls. How flavour and appearance affect human feeding. Proceedings of the Nutrition Society 41.2 (1982): 109-117.
6. Redden, Joseph P., and Stephen J. Hoch. The presence of variety reduces perceived quantity. Journal of Consumer Research 36.3 (2009): 406-417.
7. Harrar, Vanessa, Betina Piqueras-Fiszman, and Charles Spence. There’s more to taste in a coloured bowl. Perception 40.7 (2011): 880-882.
8. Oberfeld, Daniel, et al. Ambient lighting modifies the flavor of wine. Journal of Sensory Studies 24.6 (2009): 797-832.
9. Dunne, Tracy E., et al. Visual contrast enhances food and liquid intake in advanced Alzheimer’s disease. Clinical Nutrition23.4 (2004): 533-538.

Caroline Wood is a Communications Officer for the Nuffield Department of Population Health at the University of Oxford. Her role is to use strategic communications to maximise the impact of health-related research. She is also a freelance science writer specialising in food science, sustainability and plant science topics. Caroline holds a PhD from the University of Sheffield, with her thesis subject being parasitic plants that impact food security. She greatly enjoys science public engagement and led a volunteer science engagement group for several years during her PhD. In her spare time, she enjoys hill walking, painting and writing novels.

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