Sights and colors matter, especially when it comes to food. You might have heard that man is a social animal but the new International School for Advanced Studies (SISSA), Italy, study proves that man is a “visual animal”. Scientists have discovered that our vision guides us into making food choices – color green unconsciously renders food less nutritious; red more nutritious.
The study was coordinated by Raffaella Rumiati, a neuroscientist and the chief author, who believes “we judge food”. According to the scientists, we rely on a “color code” to calculate the amount of calories in the food.
The human trichromatic vision – three classes of photoreceptors are located in the light-sensitive organ of the eye, called the retina — is important in the evaluation of food. The attention we give to food is linked with the color red while green is negatively associated with calorie content.
The human trichromatic vision is responsible to correctly depict colors and textures of objects. There are two types of cells in the eyes responsible for vision: rods (rod shaped cells) and cones (cone shaped cells). The rods are responsible for low light vision while the cones are responsible to differentiate colors and work in bright light.
The cones have three types of receptors, each of which is sensitive to the primary colors: red, blue and green. These three colors when combined give us any visible color in the electromagnetic spectrum.
We see more colors than monochromatic and dichromatic animals, where some are only able to see in black and white and others are able to see some colors.
Attentiveness towards an item is a motivation for us towards any object, especially food, and shows wanting. To test this hypothesis, the scientists asked healthy participants to rate how they viewed a large set of non-food and food images. They also asked the participants to rate the level of transformation of different food images.
The characteristics of the participants like Body Mass Index, height and hunger level as well as visual properties such as size and spatial frequency were also evaluated.
The results showed that red color increased state of arousal of mind while green color negatively depicted calorie content when compared to actual calorie content.
The researchers concluded that we are particularly efficient in differentiating red from green. That is why color of food matters more to us than a dog, who use their sense of smell to judge whether food is consumable or not.
The study was published in Scientific Reports.
The reason we look at food this way is related to its nutrition and calorie dense content like red meat. Raffaella Rumiati says, “”According to some theories, our visual system evolved to easily identify particularly nutritious berries, fruits and vegetables from jungle foliage.”
He adds, “We are particularly efficient at distinguishing red from green. It is mainly the color of food that guides us, and our experiments show how. To date, only a few studies have been focused on the topic.”
Color is a good indicator of calories. The redder the unprocessed food is, the more likely we are to perceive it as nutritious while we view green foods as low in calories.
The results of the study also showed that cooked foods are favored over natural foods although color loses its vividness as an indicator of calories. When we cook food, the scientists explain, the dominance of red over green no longer provides proper information. This shows that the brain does not apply the “red over green” concept on processed foods.
Moreover, choosing red over green does not apply to nonfood items. This shows that the “color code” is activated only in sight of food.
So What Neurochemical Changes Occur In Brain When It is Gastronomically Aroused?
It is no coincidence that brain is close to our mouth and one of the brain’s main roles is to facilitate eating. In sight of food, certain neurological changes take place and that is why cognition has a profound effect on even the images of food.
Such images alter the neural activity and elicit physiological and psychological responses to the ‘hungry’ brain.
Our brains simply enjoy seeing food because it gives us pleasure which might lead to an automatic reward to our taste buds and digestive system if we acquire the food by various ways like cooking and buying food and dining out.
A study pointed out this exact phenomenon by using functional magnetic resonance imaging (fMRI) to better understand how and where neural activity takes place in the brain when food cues are used as visual stimulus.
The results showed that fattening food has a greater activation of the brainstem, left amygdala, hypothalamus, left orbitofrontal and right insular cortex, caudate nucleus, putamen and occipital lobe just to mention a few of the activated brain regions.
In contrast, only the occipital region showed greater activation by non-fatty food items.
This cascade of neural activity is the reason food advertisements are placed aggressively by food companies to take advantage of the hunger system of humans to make us buy more of their food products than necessary. In addition, bookstores are sagging under increasing weight of cookbooks filled with high-definition and digitally-enhanced food images and ways to cook these elaborate dishes.