Most people know about our 5 senses:
- Sight
- Smell
- Touch
- Hearing
- Taste
But that’s only part of the story because in actual fact we have 8 senses. The remaining 3 often get left out but they are experienced across our entire body:
- Vestibular – sense of balance
- Proprioception – sense of movement
- Interoception – the sensation of things that are happening inside your body
So, how many of our senses do we use when eating?
Answer: all of them!
While we mostly tend to focus on our sense of taste when describing a meal, by the time we’ve finished eating we have involved every single one of our senses.
Eating is one of the most sensory challenging tasks that we do, and we do it multiple times per day.
Let’s look at the sensory systems one by one, and the role they play in our ability to eat.
Visual (Sight)
Sight tells us a lot about a food. The appearance of a food can influence whether or not we want to eat it. If you had the choice between brown slop or a pizza, I think most of us would choose the pizza. Even if the brown slop was pureed pizza and tasted exactly the same, the unappetising appearance would likely be enough to turn your stomach and put you off eating.
Our sense of sight also sets expectations for a meal. If the food looks familiar then we already have a previous experience to draw on and know what to expect when we eat the food. If we’ve ever had a negative experience with that food, for example choking, then the look of the food may remind us of that and make us not want to risk it happening again.
Olfactory (Smell)
A great smelling meal really enhances our desire to eat. And a strong or off-putting odour can do the exact opposite. Much like the sight of food, familiar food odours can also let us know what to expect from a meal.
If bolognaise is simmering away on the stove then the whole house is filled with the smell and you know dinner tonight is going to be delicious.
On the other hand, if a food ever made you sick then just one whiff can be enough to make those bad memories and nausea come flooding back.
Our sense of smell is also often relied upon to help us to decide if a food is safe to eat and hasn’t gone off – not that this can always be trusted!
Tactile (Touch)
Our sense of touch is not limited to our fingertips. A relatively large area of our brain that processes touch is dedicated to our lips, tongue, teeth and gums. How a food feels in our mouth is all part of the sensory experience of eating, and many of us have preferences for food textures.
Some may like foods that feel dry in the mouth, while others like wetter textures. Much like sight and smell, previous experiences can influence these preferences. For example, if we gagged on a puree once before then it could possibly induce that same reaction when the smooth sensation of the puree hits our mouth.
Auditory (Hearing)
Food and eating make sounds, even if it’s something that you’ve never really paid attention to.
One of the joys of eating crunchy foods is that very satisfying sound it makes as you bite into it. And some people love the slurping sound they make when eating a soup. Others absolutely hate this noise, especially when the sound is being made by someone else!
Gustatory (Taste)
As I’ve already mentioned, this is the main sense that we associate with food. You are probably aware of the 5 tastes – sweet, sour, salt, bitter and savoury (otherwise known as umami). We have receptors for taste all throughout our mouth but they are in the highest numbers on our tongue.
Sweet tasting foods generally indicate a good source of energy therefore we have evolved with a strong preference for sweet flavours, and we generally like a sweet food on the first taste. Bitter flavours, on the other hand, tend to be associated with poisonous foods and therefore foods with this taste are generally approached with caution.
Vestibular (Balance)
We often take our ability to not fall over every second of the day for granted. Being able to successfully sit (or stand) upright while eating is in large part thanks to our vestibular system.
Chewing food challenges our sense of balance but most of us would never be conscious of this.
Not convinced? Try sitting on a stool with no back support, feet up and eyes closed while chewing a piece of steak. Once you take away the sense of sight, you’re likely to become more aware of the vestibular system.
Proprioception (Movement)
This is another sense that tends to be taken for granted. All day long you are receiving sensory input relating to how your body is moving, whether it’s to sit down on a chair or walk through a doorway. Every little (and big) movement is successfully executed thanks to our sense of proprioception. When we eat it’s our proprioception that helps guide our hand to deliver food into our mouth, and not to our forehead.
Interoception (Internal)
Interoception is possibly the least well known of the 8 senses. It refers to the internal signals that we get from our body, for example feeling hungry or thirsty, the sensation of needing to use the bathroom, or feeling pain.
Our interoception is often what drives food intakes. If we feel hungry then we will seek out foods to eat, and then once we get to a feeling of fullness we generally stop eating (but not always).
Everyone experiences sensory inputs in their own way. Sensory experiences are a mixed bag – they can be positive experiences (think delicious foods) or negative (the smell of rotting fish). How sensitive we are to inputs can also influence whether our experiences are positive or negative.
Some people are hyper-responsive to sensory inputs. This means that they are very sensitive to sensations. For example a ‘super taster’ is hyper-responsive to taste. Hyper-responses can potentially be a negative experience as they can cause physical discomfort.
Others are hypo-responsive, meaning they need a very large sensory input before it triggers any sensations. For example, someone with a very high pain threshold is hypo-responsive to interoception. This could be seen as a positive on one hand, and on the other a negative because it means they may hurt or injure themselves because they weren’t aware their body was under threat.
Hyper- or hypo-responses can have a huge impact on our ability to successfully eat a meal or a particular food, and often feeding difficulties are the result of these experiences.
Stay tuned for the next part in Sensory Experience of Eating series, where we look at hyper-responses in more detail, and their role in feeding difficulties.
In the mean time, do you or a loved one need support managing the sensory aspects of food? Our team are here to help!
Dietitian Michelle Saunders has a particular passion for this area.
