Eat vanilla yogurt, be happy, says research

Being pleasantly or unpleasantly surprised by the taste of something can change a person's mood, according to research published in Food Research International.

Vanilla yogurt elicited a positive emotional reaction in tests, researchers say

There is a growing conviction that emotional reactions to the consumption of foods or the perception of fragrances play an important role in the acceptance of products in the market.

However, it is not clear how to measure this reliably.

Previous tests have had the disadvantage of being heavily language-based, of tending to suggest feelings that people might have but perhaps never did, and of fixating the respondent's explicit attention on the food or the odor under consideration, rather than on implicitly expressing their feelings.

In the search for a simple method to measure implicit and unconscious emotional effects of food consumption, a team of researchers from the Netherlands, Austria and Finland, used four different techniques to measure people's emotional responses, and to find out what emotional effects, if any, eating different yogurt had on people.

Testing for emotional reactions to food

Three groups of at least 24 participants were each given a pair of yogurts to taste, and the four tests were carried out around this activity. The pairs of yogurts were of the same brand and were marketed in the same way, but they had different flavors or fat content.

The four methods used to measure emotional response were:

  • Face reading during consumption
  • A new emotive projection test (EPT)
  • An autobiographical reaction time test based on mood congruency
  • Eye tracking to measure the impact of the packaging.

EPT was used to determine the effect of different yogurts on people's moods. It involved showing participants photographs of other people and asking them to rate the people in the photographs on six positive and six negative traits before and after eating the yogurt. The idea is that people project their emotions onto others, thus giving an indication of their own mood.

The eye-tracking test aims to characterize gazing behavior and visual attraction of stimuli, and was used to evaluate the food packaging. Gazing behavior can be influenced by emotional reactions, but the results of the eye-tracking measurements are not able to describe emotion states.

Results from the face-reading test were hindered due to technical difficulties, and the autobiographical test results were not significant, but the other tests yielded interesting results.

Comparing eye-tracking measurements before and after eating the yogurt showed the effects of familiarity but not necessarily emotion.

The team found that that liking or being familiar with a product had no effect on a person's emotion. What did affect the emotions was changes in attitude to the food after tasting it. Being pleasantly surprised or disappointed about the food appears to influence people's moods.

Positive response to low-fat yogurts

The team also looked at the sensory effect of the yogurts. There was no difference in the emotional responses to strawberry versus pineapple yogurts, but low-fat versions led to more positive emotional responses.

Most strikingly, vanilla yogurt elicited a strong positive emotional response, supporting previous evidence that a subtle vanilla scent in places like hospital waiting rooms can reduce aggression and encourage relationships among patients and between patients and staff.

The team found that eating vanilla yogurts made people feel happy and that yogurts with lower fat content gave people a stronger positive emotional response.

They also found that even if people reported differences in liking them, yogurts with different fruits did not show much difference in their emotional effect.

Lead author of the study, Dr. Jozina Mojet from the Netherlands, says:

"This kind of information could be very valuable to product manufacturers, giving them a glimpse into how we subconsciously respond to a product. We were surprised to find that by measuring emotions, we could get information about products independent from whether people like them."

Traditionally, products have been trialled using explicit methods, such as directly asking people how they feel. In contrast, the new method is implicit and therefore not controlled by people's conscious thought.

Dr. Mojet believes that sensory and consumer research should be conducted in an ecologically valid way and suggests this sort of implicit method can reveal the complex interactions between the different factors involved, which may be affected by the individual's memory and expectations.