The reason we choose a high-calorie dessert may be more complex than you think. Sure, it often tastes good, but before we even get a chance to consciously decide we want it, subconsciously perceived stimuli is already driving us toward it.

A new study published in the journal Appetite examined the choices study participants made after being exposed to a variety of stimuli prior to being offered a buffet of food. Before they were even aware the study had began, the participants were asked to sit in a waiting room for 15 minutes. They were divided into four rooms with four separate conditions: a control condition, an olfactory condition, an auditory condition, and a combination olfactory/auditory condition.

The control group received no stimulation, and simply sat in a quiet, unscented waiting room. The olfactory group sat in a room where they were exposed to a “pan au chocolat” — chocolate croissant — odor, and the auditory group sat while a radio aired information about the dangers of fatty and sweet foods. The combo group was exposed to both the chocolate scent and the radio program.

All of the groups were brought to a separate room where they were told to serve themselves a starter, main course, and dessert from a buffet. Researchers observed that those who were unknowingly exposed to the chocolate scent were more likely to go for high-calorie desserts, like a waffle, than those who had not been exposed to the scent. This was also true for the group who was exposed to the scent and nutritional information simultaneously.

What surprised researchers most, however, was that participants exposed only to the radio program about the dangers of fatty foods were also more likely than the control group to choose a high-calorie dessert. “We can assume that people who are faced with a complex and potentially overwhelming set of health messages every day do not pay attention to these messages,” the study authors write. “Consumers are exposed to hundreds of advertising messages per day and cannot pay attention to all of them.”

This means that messages using words like “fatty” and “sweet” may be unintentionally driving consumers towards high-calorie foods, regardless of what the message is actually saying. People may be subconsciously focusing on these key words instead of the meaning surrounding them.

The experiment used only a small sample size (147 people), and further research would be needed to determine the impact of factors such as gender and age. The study did, however, provide valuable insight into the factors that may be influencing our food choices without our knowledge.

Source: Chambaron S, Chisin Q, Chananet C, Issanchou S, Brand G. “Impact of olfactory and auditory priming on the attraction to foods with high energy density.” Appetite. 2015.