Impact of olfactory priming on mental representations of food concepts and subsequent food choice

Previous research suggests that food odors act as a prime and influence food choice outside of awareness. Little is known about how odors prime (healthy) food choices. We hypothesized that odors could activate mental representations of food concepts, interacting with cognitive processes underlying food decision-making. We tested this by examining which concepts (healthy, sensory, or product-specific) are activated by odors and how this impacts subsequent food choices. In a between-subjects design, 112 participants were divided into three conditions: healthy odor (apple or banana), unhealthy odor (chocolate or caramel), and non-odor (control). Participants were exposed to one condition for 5 min and then completed a lexical decision task and a screen-based food choice task. The lexical decision task included four word categories: healthy-related, sensory-related, neutral words, and non-words. Reaction times were recorded and computed for each category. Participants were asked to choose one food they wanted to eat from four (in-)congruent food word options and repeated it four times (one for each odor). Results showed participants responded slower to non-words than other words, and slower to healthy and sensory words than neutral words. However, odor exposure did not influence reaction times, nor did the interaction between odor condition and word category affect reaction times. Participants were more likely to choose unhealthy foods regardless of odor exposure. Thus, ambient sweet odors did not prime food-related information or choice. We recommend additional testing using a broader range of odors and word categories to fully validate the association of an odor with a concept.