To achieve these aims, a sample of 66 children ages 4-7 years (36 with avoidant/restrictive eating and 30 typically developing age/sex matched healthy controls) participated in the study. Participating children and their parent completed a parent interview of child avoidant/restrictive (AR) eating symptoms, parent questionnaires (assessing eating and feeding behavior, child emotional-behavioral functioning, sensory perception, and parent mental health), and a child behavioral and physiological assessment of sensory perception and eating behaviors at the laboratory. At the laboratory assessment, each child complete three tests of sensory perception; U’Sniff test (odor identification), mystery box (tactile perception), and PROP test (bitter flavor detection); followed by small meal with their parent that was later coded for parental feeding and child eating behavior.
The findings from this study showed that sensory sensitivity symptoms of AR eating were associated with parental report of tactile and taste/odor sensory problems but were not related to behavioral tests of odor identification and bitter taste perception, the child’s self-rated enjoyment of sensory stimuli, or activation of facial action units associated with disgust expressions and negative affect more broadly. Hyperactivation of the defensive motive system, assessed via heart rate and electrodermal activity response to sensory stimuli and eating, was not found to be associated with fear or sensory sensitivity symptoms of ARFID. However, heart rate dynamics in response to odor stimuli were consistent with delayed odor inhalation among children with elevated sensory sensitivity symptoms (Figure 1). This suggests that these children may have been behaviorally avoiding odor stimuli. However, it should be noted that odor stimuli were always presented first during the experiment, so this effect could be unique to odor stimuli or driven by the novelty of the sensory stimuli presentation. Further, child trait anxiety was found to be associated with both fear of aversive consequences symptoms of ARFID, as well as sensory symptoms, suggesting it is not a uniquely linked to fear symptoms.
As no clear biological vulnerabilities for the sensory sensitivity and fear of aversive consequences symptoms were identified in this study, the relationship between parental feeding behavior and child eating was evaluated in the whole sample, exploring child sensory perception and anxiety as moderators. These analyses suggest that when children are presented with standardized foods, the relationship between increased child food refusal and greater parental pressure to eat is observed only among children with altered sensory perception (those who could taste the PROP bitter flavor and those with low odor identification accuracy). However, as PROP taster status and odor identification accuracy were not linked to ARFID symptoms, these do not represent unique vulnerabilities for children with ARFID, but instead young children more broadly. Further, as parental pressure to eat was unrelated to the number of bites eaten by the child, these data suggest that parental pressure to eat may be more associated with mealtime conflict rather than enhanced nutritional intake by the child during the meal.
These findings have been disseminated to the academic medical community via four international research conferences as well as to the public at a local science night in Geneva, Switzerland. Further, the findings of the study will be communicated to children and their parents affected by avoidant/restrictive eating in Geneva, Switzerland through a psycho-educational group and a parent newsletter.
