Psychologists tracked the craving for sugar cookies through eye movements.

During the holidays, people often indulge in high-calorie foods, leading to weight gain. It can be particularly challenging to resist sweets. A team of psychologists from the Karl-Franzens University of Graz (Austria) used special glasses that track gaze to investigate how information about the presence or absence of sugar influences visual attention and preferences. The experiment also incorporated a Christmas theme to determine whether this context enhances the appeal of sweets.

The study, detailed in an article published in the journal Acta Psychologica, involved 58 men and women aged between 17 and 49 years (with an average age of 25) who had a normal body mass index (BMI averaging 22.2, plus or minus 3.2). All participants lived in Austria, celebrated Christmas, and were familiar with local Christmas traditions and foods.

For the participants, six stimulus items were placed on a table. Among them were four cookies, some containing sugar and others without, as indicated in their labels. Two types of cookies were related to traditional Christmas baked goods sold in Austria during this festive season.

Two of the stimuli were non-food items represented by gift-wrapped presents. The explanation indicated that one gift was for Christmas, while the other was for a birthday.

Volunteers looked at the stimuli for two minutes while wearing eye-tracking glasses that recorded their eye movements. The analysis of the data considered the duration of gaze on the items and how thoroughly they were examined.

Afterward, participants rated how visually appealing each sample was and whether it sparked a desire to eat or receive it. Additionally, the subjects provided information about their socio-demographic data and dietary preferences through questionnaires, including their views on healthy eating. To further explore food preferences, participants were offered the choice of a low-calorie or high-calorie treat—a clementine or a gingerbread cookie—at the end of the experiment.

The results revealed that Christmas-related items, both edible and non-edible, attracted more attention, as evidenced by prolonged gazes at these stimuli. The most appealing item turned out to be the Christmas cookie with sugar: this was confirmed by longer gazes and desirability ratings in the surveys. Cookies without sugar were preferred to a lesser extent, even in the case of the Christmas version.

The psychologists noted that the gaze patterns of participants toward the cookies labeled "sugar-free" exhibited characteristics observed in other studies during critical examinations of negative visual stimuli. According to the researchers, this may indicate a distrustful attitude.

Another noteworthy detail was that the sugary cookies were found to be more appealing even to volunteers who emphasized the importance of healthy eating for them. Moreover, many participants chose the gingerbread cookie at the end of the experiment, further confirming the attractiveness of festive sugary treats despite their inclination towards a healthy diet.

Based on the experiment's findings, the scientists concluded that the effect of sugar-related information was counterproductive: instead of attracting, the sugar-free cookies were found to be less desirable and appealing. However, the psychologists acknowledged that the study has limitations, suggesting that it should be repeated with a larger and more diverse sample of participants, as well as additional stimuli.