(P28-013-23) Validation of Ultra-Processed Food-Related Stimuli for Use in an Implicit Association Task

Objectives: The Implicit Association Task (IAT) is a validated reaction time task used to study the underlying cognitive mechanisms informing substance use behavior by measuring the relative strength of association between two mental concepts (e.g., the association between ultra-processed food (UPF) and positive reinforcement (e.g., desire to “approach” or “avoid” UPF)). The IAT has not been used to evaluate cognitive mechanisms informing UPF intake, thus validated stimuli are needed. This study validated UPF and non-UPF stimuli for use in an IAT.

Methods: Photographs of foods were taken to represent eight pairs of similar UPFs and non-UPFs per the Nova Food Classification System: French fries vs a baked potato, sugary cereal vs oatmeal, fruity candy vs blueberries, candy bar with nuts vs mixed nuts, ice cream vs cow’s milk, fast food fried chicken vs grilled chicken, cheesy snack chips vs baby carrots, and a fast food hamburger vs grilled steak. Selections were made to include all MyPlate food groups and paired according to like ingredients or sensory attributes. Serving sizes were matched by volume. Foods were presented on white or clear glassware on a white background. Final images were distributed via Qualtrics on Amazon Mechanical Turk; respondents ranked each from 0-10 (0=completely unhealthy, 10=completely healthy). Five quality control questions were included; responses were omitted if >1 was failed. Sign tests were used to detect differences across image ratings in each pair. The absolute value of the difference between images in each pair was computed to compare the magnitude of the difference in perceived healthfulness.

Results: n=100 individuals completed the survey. Within pairs, all sign tests were P<0.01, indicating a significant difference in perception of UPF and non-UPF stimuli, as expected. Fruity candy was ranked most unhealthy (mean score=0.7), and baby carrots were ranked most healthy (mean score=9.4). Across pairs, differences in ranking were highest for cheesy snack chips vs baby carrots (8.0), while the lowest was for a fast food hamburger vs grilled steak (2.7).

Conclusions: Study participants indicated a consistent difference in perception of UPF and non-UPF stimuli, thus the images generated from this work are valid for use in a UPF-specific IAT.

Funding Sources: This work was supported in part by a TSET Health Promotion Research Center Seed Grant.