Differences in Perceived Versus Actual Sensory Perception in Avoidant/Restrictive Food Intake Disorder.

Background: Individuals with avoidant/restrictive food intake disorder (ARFID) self-report heightened sensitivity to taste and smell, but neither phenomenon has been systematically explored in the laboratory. We hypothesized that, compared to healthy controls (HC, n = 34), children, adolescents, and adults with full/subthreshold ARFID (n = 100; ages 9 to 23 years) would self-report heightened response to taste/smell stimuli and exhibit stronger bitter taste perception and heightened smell perception in performance-based tasks, and these differences would be especially prominent in those with the ARFID-sensory sensitivity presentation.

Method: We measured self-reported sensitivity to taste/smell with the adolescent/adult sensory profile (AASP). We measured performance-based bitter taste perception with the regional taste intensity test (RTIT) and 6-N-propylthiouracil (PROP) test, and olfactory performance with the Sniffin' Sticks test (including the odor threshold, odor detection, and odor identification subscales).

Results: As expected, the ARFID group self-reported heightened response to taste/smell on the AASP, compared to HC, with an especially large effect size in the subset with the ARFID-sensory sensitivity presentation. Contrary to hypotheses, on performance-based measures, neither the ARFID group-nor the ARFID-sensory sensitivity group specifically-demonstrated heightened sensitivity to bitter taste on the RTIT or PROP tests, nor heightened smell perception on the Sniffin' Sticks test.

Conclusion: These first laboratory findings in a clinically diagnosed sample of individuals with full/subthreshold ARFID highlight the discrepancy between perceived versus actual sensitivity to taste/smell stimuli. Future research should explore whether this discrepancy can be replicated and therapeutically leveraged to facilitate successful food exposures.