Almost everything we eat affects our brain through the hormones and nutrients in it, but the other way around our brain also influences what we eat and how we perceive it. Food research is an interesting field where perceptions and assumed interplay of our brain and food is challenged every time. There have been some really great experiments in the area of food and perception and after one piqued my interest I went on a search and listed the most interesting studies in 4 categories.
1. Food colour may change taste perception
One of the most famous studies is one where French researchers coloured a white wine red with an odourless dye and asked a panel of wine experts to describe its taste. Both red and white wine have several different descriptors, making it possible to distinguish which descriptors would be used by the connoisseurs. In the study mostly red wine descriptors were used to describe a white wine looking red.
Above study shows that the colour played a significant role in the way the white wine was perceived, even though red and white wine taste very different. However, as a critique on this study I think that the fact that there are only two kinds of wine (yes, out of three) leads to expectations that trigger a particular vocabulary. The research shows us exactly that, but it also lacks the blindness of unbiased perception. The participants could have been biased based on previous experiences and current expectations. Thus, to support the claim that colour influences taste I set out to search for further evidence.
And more evidence is exactly what I found. There was a study showing that added food colouring has an effect of up to 10% on perceived sweetness of the food, depending on the colour (red being the sweetest). Another one gave people a colourless soda which was either lime, strawberry or orange flavoured or didn’t have a flavour at all. When the researchers started playing with food colourings, the participants ability to determine the flavour of the drink was severely impaired by the food colouring, even after being told to ignore the colouring completely. Another fun fact is that the intensity of the colour had no influence, bright red or barely red was still red for the brain.
The last study I found on this subject feels somewhat unethical, but shows us in a somewhat dark humorous way that colour perception is a very powerful thing. People were invited over for a free meal of steak, chips and peas. They might have found it odd that the lighting in the room was very dim, but nonetheless they enjoyed the free meal. Halfway through the dinner the lighting was turned up to a normal level, showing the true exterior of the food: the steak was coloured blue, the chips green and the peas red. This led to a lot of the guests suddenly feeling ill and several rushing to the bathroom. (last 3 studies from flavourjournal.com)
All these studies support the claim that food colour changes our perception of the food, from making us think the food is sweeter to even making us ill.
2. Food texture and shape may trick the mind
The second point on this list is once again based on our direct perception of food and the influence it has on our brain. There has been a study showing that food shapes influence the taste perception. For example a round shaped food would make you think that the food is sweeter, whilst angular shapes might make a food more bitter.
Another study has a tad more story behind it. The shape of Cadbury’s Dairy Milk chocolate was changed, but not its recipe. When this happened, consumers on internet forums complained en masse about a change in the taste. The Nestlé Research Centre picked up on this and with a study of 10 different chocolate shapes they found significant differences in the perceptions of melting characteristics and smoothness, but also smaller differences with cocoa and caramel flavours and aftertaste.
A study on food textures attempted to show how ketchup tasted and the relation between how tasty it looked and felt. They did this by showing participants a video of a spoon of ketchup being taken out of a bowl, where the lighting was altered to make it look like it had another texture each time, and then taste it. The results suggest that visual texture, independent of colour, affects the taste and flavour.
3. Labels can lie and you would never know
Continuing with interesting experiments showing how your perceptions of food change depending on what you think of it: there has been a study with milkshakes. I found this in an article on time.com and was intrigued by the results, leading me to write this article. Participants in this study were given a milkshake which was labelled “140 kcal sensible” or “620 kcal indulgent”. Both milkshakes had the same caloric value of 380 kcal. The study reports that participants that had the indulgent shake experienced more satiety than the sensible shake group, which was reflected by lower ghrelin (the hunger hormone) levels.
Another study shows that food desirability can be modified by how it’s marketed. Study subjects showed different brain activity (increased OFC activation, a part of the brain that influences decision making and gets activated when we deal with food) when presented either a cheap or an expensive wine, which was the same wine after all. The same happened in a different study where the same food was labelled either as having a “rich and delicious flavour” or as “boiled vegetable water”. It seems food marketing does work after all.
4. Your brain determines what food you want to eat
There are two values your brain considers when deciding what to eat. The most important one is taste, with your brain having recollections of what food tastes like.
The second one is a food’s nutritive value. The brain has ways of detecting nutritive values independently of taste. Studies with mice and fruit flies have shown that both prefer a more nutritive sugar over a nonnutritive one when their taste receptors were knocked out. The brain released dopamine when they had ingested the nutritive sugar, allowing them to figure out what was nutritive and what was not without tasting. (source greymattersjournal.com)
Another study shows that the visual representation of caloric values of food effects the food buying behaviour in a cafeteria setting. Adding caloric signs to food significantly decreased the total number of calories bought. This means your brain, perhaps even unconsciously, determines how much you want to eat and results can change based on the conscience of the decision.
Food research turns out the be pretty awesome. From experiments making people feel ill and rushing to the bathroom to making people drink things and having no idea that they’re being tricked into tasting something different. It shocked me though that the number of ways through which our senses influence our food perception is so high. The idea that shape, colour and texture influence the taste as well as that labels influencing the satiety I experience make me wonder in what other ways the brain influences food perception that we don’t know about yet.
In conclusion and based on this article I would like to propose a round, red vegetable with triple the calorie amount on the label as a diet plan. This will screw the brain op and be a definite success. Who’s with me? (kickstarter coming soon)