Relationship between Food Selectivity and Sensory Hyper-Responsivity in Children with Autism Spectrum Disorder: A Qualitative Study

Background: Sensory hyper-responsivity is one of a major symptomatic condition in individuals with autism spectrum disorders (Marco et al., 2011). This symptom appears in various types of modalities and have been suggested to associate food selectivity (Cermak et al., 2010). Children with ASD are overly selective in their eating patterns that they are lack of food variety in intaking flesh fruits and vegetables especially in their earlier developmental stage (Emond et al., 2015). Whereas several studies that examined relationship between sensory hyper-responsivity and food selectivity by quantitative investigation using several questionnaires, little is known about its neurophysiological basis.

Objectives: To obtain more information with regard to the influence of sensory hyper-responsivity on food selectivity in children with ASD, we conducted a study applying a qualitative KJ method which is generally accepted in language data analysis.

Methods: Four children with ASD (7 ~ 14 year-olds male, respectively) and their mothers were participated. The mother answered the Short Sensory Profile (SSP; Tomcheck & Dunn, 2007) which evaluate the severity of hyper- / hypo-responsivity. Three out of four children were over 1 or 2 standard deviation of the standardized mean both in the total score (62, 87, 125 / maximum of 190) and sub-category of Taste / Smell Sensitivity (6, 6, 20 / maximum of 20). Thus, we defined them as ‘High sensitivity type’ relative to a child defined as ‘Low sensitivity type’. Semi-structured interview (30 ~ 50 min) was performed using a guideline which we had developed. We heard “favorite foods” and “disliking foods” as well as those texture and other sensory features for the children and mothers. The authors classified the foods according to that the children are favorite or disliking, and made categories following semantic similarities after putting labels as to speech contents.

Results: We mainly focused on differences between High and Low sensitivity types. We found 3 categories and 8 sub-categories in High sensitivity types (Figure 1). “Difficulty of chewing and swallowing” was related with pickiness to avoid foods that is not easy to eat and bite. “Hyper-responsivity to food texture” was related with avoiding foods’ textures and shapes which influence easiness to swallow. They disliked sticky, dry, limp textures of the foods. The category involved preference to eat dark taste. Avoiding of intaking of flesh fruits and vegetables was found. “Atypical picky to food appearance” involved hesitating to eat from foods’ appearance. In contrast, Low sensitivity type tended to prefer to weak tastes’ foods and flesh vegetables. Influence of visual appearance of foods did not be reported.

Conclusions:Our qualitative study demonstrated that food selectivity is constructed several factors which are shared with all children with ASD having high sensory hyper-responsivity. The result that both “difficulty of chewing and swallowing” and “Hyper-responsivity to food texture” contributed food selectivity was seemed to derived from sensory abnormalities when taking the foods. Chewing and swallowing can be done functioning various nerves in the swallowing reflex. The current study suggested that sensory and motor disabilities might be underlying in food selectivity.