Impact of Selective Eating on Social Domains Among Transition-Age Youth with Autism Spectrum Disorder: A Qualitative Study

Dietary intake in children on the autism spectrum is altered and linked to differences in autistic traits and sensory processing styles

Diets of children and adolescents on the autism spectrum often differ when compared to their non-autistic peers. Most dietary studies have been limited by small sample sizes and rarely assess the heterogeneity of autism. Addressing this gap, this study compared the anthropometrics, dietary composition, dietary quality, and food variety of 154 Australian children and adolescents on the spectrum and 213 non-autistic children (71 siblings and 142 unrelated controls). Beyond the case-control approach, within-group comparisons assessed the influence of autism clinical presentations and sensory processing styles on body mass index (BMI) and measures of dietary intake among those on the spectrum. In this word first study of diet that included between-group comparisons with non-autistic peers (siblings and an unrelated comparison group) and within-autism group comparisons, we found that children on the spectrum consumed limited variety and lower quality of food and non-autistic siblings also ate comparably higher levels of energy-dense, nutrient poor food, and less diary. This may be due to autistic traits influencing family's diets or shared sensory sensitivities driving dietary intake. Within the autism group, higher autistic traits were associated with lower BMIs and a specific dietary pattern higher in simple carbohydrates and lower in unprocessed protein. Contrastingly, greater sensitivity to sensory stimuli was associated with a healthier diet. Increased age was linked to more varied diets but also diets higher in saturated fats and energy-dense, nutrient poor foods. Overall, this research highlights that potential mediators of dietary intake, such as familial influences, autistic traits, sensory processing styles, age and sex, need to be considered when assessing diet in the autistic population. LAY SUMMARY: In this study of dietary differences linked to autism, children, and teenagers on the spectrum ate fewer different foods and were less likely to eat recommended amounts of fruits and vegetables when compared to non-autistic siblings and unrelated children and teenagers. There were also family differences, in that those on the spectrum and their siblings ate more unhealthy foods and less dairy. Among those on the spectrum, dietary differences were linked to age, sex, autistic traits and sensory processing styles.

Eliciting Expressions of Emotion: An Exploratory Analysis of Alexithymia in Adults with Autism Utilising the APRQ

This study examined alternative methods for detecting alexithymia to the Toronto Alexithymia Scale-20 (TAS-20) by comparing the emotional linguistic performance of ASD and NT samples (n = 32 in each) on the Alexithymia Provoked Responses Questionnaire (APRQ). We utilised both the LIWC and tidytext approaches to linguistic analysis. The results indicate the ASD sample used significantly fewer affective words in response to emotionally stimulating scenarios and had less emotional granularity. Affective word use was correlated with ASD symptomatology but not with TAS-20 scores, suggesting that some elements of alexithymia are not well detected by the TAS-20 alone. The APRQ, in combination with the tidytext package, offers significant potential for sophisticated exploration of emotional expression in ASD.

Feeding and eating problems in children and adolescents with autism: A scoping review

LAY ABSTRACT

Feeding problems, such as picky eating and food avoidance, are common in youth with autism. Other, broader difficulties with feeding and eating (eating disorder symptoms such as restricting food intake or preoccupation with body shape or weight and insistence on specific food presentation) are also common in autistic individuals. Here, we describe the nature and extent of feeding and eating problems in youth with autism. We found no common characteristics (such as severity of autism symptoms) that best describe autistic youth who experience problems with feeding or eating. Almost all studies we reviewed focused on problems with feeding (selective or picky eating), and only a few studies focused on eating disorder symptoms (concern with weight, shape, and/or body image). However, some researchers reported that eating disorder symptoms may occur more often in autistic individuals compared to their peers without autism. Many studies used the terms "feeding" and "eating" problems interchangeably, but understanding the difference between these problems is important for researchers to be consistent, as well as for proper identification and treatment. We suggest future researchers use "eating problems" when behaviors involve preoccupation with food, eating, or body image, and "feeding problems" when this preoccupation is absent. We highlight the importance of understanding whether feeding or eating problems are separate from autism traits, and the role of caregivers and other adults in the child's treatment. Considerations for health-care providers to assist with diagnosis and treatment are also provided.

Improving the measurement of alexithymia in autistic adults: a psychometric investigation and refinement of the twenty-item Toronto Alexithymia Scale

BACKGROUND

Alexithymia, a personality trait characterized by difficulties interpreting one's own emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies a number of cognitive and emotional differences previously attributed to autism, such as difficulties in facial emotion recognition and reduced empathy. Although questionnaires such as the twenty-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have attempted to determine the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults.

METHODS

We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 verbal autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study (the Human Penguin Project). The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to further refine the scale based on local model misfit and I-DIF between the groups. Correlations between alexithymia and other clinical outcomes such as autistic traits, anxiety, and quality-of-life were used to assess the nomological validity of the revised alexithymia scale in the SPARK sample.

RESULTS

The TAS-20 did not exhibit adequate global model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an eight-item unidimensional scale (TAS-8) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that TAS-8 scores meaningfully predict autistic trait levels, anxiety and depression symptoms, and quality of life, even after controlling for trait neuroticism.

LIMITATIONS

Limitations of the current study include a sample of autistic adults that was overwhelmingly female, later-diagnosed, and well-educated; clinical and control groups drawn from different studies with variable measures; and an inability to test several other important psychometric characteristics of the TAS-8, including sensitivity to change and I-DIF across multiple administrations.

CONCLUSIONS

These results indicate the potential of the TAS-8 as a psychometrically robust tool to measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced TAS-8 latent trait scores in research applications (available at http://asdmeasures.shinyapps.io/TAS8_Score ).

Association Between Peripheral Blood Levels of Vitamin A and Autism Spectrum Disorder in Children: A Meta-Analysis

Vitamin A is an essential fat-soluble micronutrient that plays important roles in a surprisingly wide variety of biological processes from early growth and development to brain maintenance. Numerous clinical studies have been conducted to explore the relationship between peripheral vitamin A levels and autism spectrum disorder (ASD), but the results of these studies are controversial. Therefore, we assessed the association between peripheral vitamin A levels and ASD in the present meta-analysis. Relevant records were retrieved through the Embase, Web of Knowledge and PubMed databases up to 13 November 2020. Reference lists were also searched and analyzed. Hedges' g with its corresponding 95% confidence interval (CI) was used to assess the association between peripheral vitamin A levels and ASD. A fixed or random effects model was selected according to a heterogeneity test in overall and subgroup analyses. Five records (six studies) with 935 ASD children and 516 healthy children were included in the present study. Significantly decreased peripheral vitamin A concentrations were observed in ASD children compared with healthy children (Hedges' g = -0.600, 95% CI -1.153 to -0.048, P = 0.033). A similar result was also obtained after removing the studies identified by Galbraith plots. In addition, no obvious publication bias was found in the meta-analysis. The findings of our meta-analysis suggested decreased peripheral vitamin A levels in ASD children compared with healthy children. Further investigations into the effects of vitamin A on the development of ASD are warranted.