Dietary intake and gastrointestinal symptoms are altered in children with Autism Spectrum Disorder: the relative contribution of autism-linked traits

Abstract

Background: Dietary and gastrointestinal (GI) problems have been frequently reported in autism spectrum disorder (ASD). However, the relative contributions of autism-linked traits to dietary and GI problems in children with ASD are poorly understood. This study firstly compared the dietary intake and GI symptoms between children with ASD and typically developing children (TDC), and then quantified the relative contributions of autism-linked traits to dietary intake, and relative contributions of autism-linked traits and dietary intake to GI symptoms within the ASD group.

Methods: A sample of 121 children with ASD and 121 age-matched TDC were eligible for this study. The dietary intake indicators included food groups intakes, food variety, and diet quality. The autism-linked traits included ASD symptom severity, restricted repetitive behaviors (RRBs), sensory profiles, mealtime behaviors, and their subtypes. Linear mixed-effects models and mixed-effects logistic regression models were used to estimate the relative contributions.

Results: Children with ASD had poorer diets with fewer vegetables/fruits, less variety of food, a higher degree of inadequate/unbalanced dietary intake, and more severe constipation/total GI symptoms than age-matched TDC. Within the ASD group, compulsive behavior (a subtype of RRBs) and taste/smell sensitivity were the only traits associated with lower vegetables and fruit consumption, respectively. Self-injurious behavior (a subtype of RRBs) was the only contributing trait to less variety of food. Limited variety (a subtype of mealtime behavior problems) and ASD symptom severity were the primary and secondary contributors to inadequate dietary intake, respectively. ASD symptom severity and limited variety were the primary and secondary contributors to unbalanced dietary intake, respectively. Notably, unbalanced dietary intake was a significant independent factor associated with constipation/total GI symptoms, and autism-linked traits manifested no contributions.

Conclusions: ASD symptom severity and unbalanced diets were the most important contributors to unbalanced dietary intake and GI symptoms, respectively. Our findings highlight that ASD symptom severity and unbalanced diets could provide the largest benefits for the dietary and GI problems of ASD if they were targeted for early detection and optimal treatment.

Keywords: Autism spectrum disorder; Autism-linked traits; Dietary intake; Gastrointestinal symptoms; Relative contributions.

Fig. 1

Flow diagram for study participants

Fig. 2

Children with ASD had poorer diets than age-matched TD children (n = 242).^a g/day. ^b Food variety scores ranged from − 12 to 0, with lower scores representing less variety of food. ^c Evaluated using the low bound score (LBS) and diet quality distance (DQD), respectively, with higher scores representing a higher degree of inadequate/unbalanced diets. Adjusted for child’s age, sex, intellectual functioning, birth mode, birth order, average daily sleep duration, maternal educational attainment, gestational diabetes mellitus, maternal obesity, monthly per-capita income, and parenting behavior. Effect size = Cohen’s f² for linear models. ASD: autism spectrum disorder, TD: typically developing, CI: confidence interval

Fig. 3

Children with ASD experienced more severe GI symptoms than age-matched TD children (n = 242). Constipation and total GI symptoms scores were evaluated by subscale and total scores of the 6-item gastrointestinal severity index (6-GSI). Adjusted for child’s age, sex, intellectual functioning, birth mode, birth order, average daily sleep duration, maternal educational attainment, gestational diabetes mellitus, maternal obesity, and monthly per-capita income. Effect size = Cohen’s f² for linear models. GI: gastrointestinal, ASD: autism spectrum disorder, TD: typically developing, CI: confidence interval

Fig. 4

Probability of poorer diets associated with autism-linked traits in children with ASD (n = 121). a, b Inadequate vegetable/fruit intake: inadequate vs. appropriate intake; c, d Less variety of food: food variety scores between − 12 to − 7 vs. − 6 to 0 (with lower scores representing less variety of food); e, f Inadequate dietary intake: moderate-high inadequate dietary intake vs. appropriate, more appropriate, and low inadequate dietary intake; g, h Unbalanced dietary intake: moderate-high unbalanced dietary intake vs. more appropriate, and low unbalanced dietary intake. ASD: autism spectrum disorder

Fig. 5

The relative contribution of autism-linked traits to the odds of poorer diets in children with ASD (n = 121). a, b Inadequate vegetable/fruit intake: inadequate vs. appropriate intake; c Less variety of food: food variety scores between − 12 to − 7 vs. − 6 to 0 (with lower scores representing less variety of food); d Inadequate dietary intake: moderate-high inadequate dietary intake vs. appropriate, more appropriate, and low inadequate dietary intake; e Unbalanced dietary intake: moderate-high unbalanced dietary intake vs. more appropriate, and low unbalanced dietary intake. Adjusted for child’s age, sex, intellectual functioning, birth mode, average daily sleep duration, average daily SB time, average daily MVPA time, average daily walking time, maternal educational attainment, monthly per-capita income, and parenting behavior. ASD: autism spectrum disorder, OR: odds ratio, CI: confidence interval, SB: sedentary behavior, MVPA: moderate-to-vigorous physical activity