There are plenty of foods out there that will make you happy, such as chocolate or eggs. But a new study looking into our emotional responses when eating something we aren't quite sure about has found that vanilla yogurt can make you especially happy.

A team of researchers from Wageningen UR Food & Biobased Research in the Netherlands, the University of Natural Resources and Life Sciences (BOKU) in Austria, and the VTT Technical Research Centre of Finland Ltd., used various methods to measure people’s emotional responses to food, specifically yogurt. The researchers found that eating vanilla yogurt can make you happy, while eating yogurts with lower fat content elicited a stronger, more positive emotional response. However, when it came to yogurt with fruit in it, even when people reported differences in their liking for it, there was no effect on participants' emotional state.

"We were surprised to find that by measuring emotions, we could get information about products independent from whether people like them," said lead author Dr. Jozina Mojet, from Food & Biobased Research in the Netherlands, in a press release. "This kind of information could be very valuable to product manufacturers, giving them a glimpse into how we subconsciously respond to a product."

To confirm their theory, the researchers used a new method called an emotive projection test to figure out how different types of yogurt affected people’s moods. They showed participants photos of people and asked the participants to rate the people in the photos based on six positive and six negative traits. In doing this, the participants would be projecting their emotions onto the people in the photos, thus giving researchers a glimpse into the participant’s overall mood.

Using three groups of at least 24 people, the researchers then handed out pairs of yogurts. All of the yogurts were the same brand, and they were marketed to the participants in the same way; however, each had different flavors or fat contents. The results showed that liking or being familiar with the brand of yogurt had no impact on participants' emotions. But after tasting it there was an effect on their mood, depending on whether they were surprised or disappointed by its taste.

The researchers also took into account the sensory effect of the yogurts. Both strawberry and pineapple flavors were found to have no emotional effect, but when the participants were given low-fat yogurts with the same flavors, they had much more positive emotional responses. Vanilla-flavored yogurt, meanwhile, elicited the strongest positive emotional response.

Traditionally when testing out a new product, companies directly ask consumers how they feel about the product. Now, however, the findings suggest this new method can be effective in gathering information because a person’s response is implicit and not controlled by their conscious thoughts.

"We were looking for a valid, quick, and not too expensive and time-consuming method to measure the emotions or mood changes evoked by food," Mojet said. "I strongly believe that sensory and consumer research should be conducted in an ecologically valid way. This sort of implicit method can reveal the complex interactions between the different factors involved in a situation, which, based on his or her memory and expectations, is given meaning by the person under investigation."

Source: Mojet, J, et al. Are implicit emotion measurements evoked by food unrelated to liking? Food Research International. 2015.