Food selectivity and neophobia in children with autism spectrum disorder and neurotypical development: a systematic review

Taste processing in autism spectrum disorder: A translational scoping review

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by persistent challenges in social communication and restricted/repetitive behaviors, including sensory atypicalities. Taste processing is critical for assessing the sensory and hedonic properties of food; however, it remains understudied in ASD, which may limit our understanding of the disorder's links to selective eating and nutritional deficits. This scoping review on autistic gustatory functioning followed a predefined protocol. We conducted searches across four databases and identified 37 studies involving human participants, categorized into three methodologies: questionnaires, neuroimaging, and psychophysical tests. Additionally, eight studies on ASD animal models were included to offer cross-species insights. Questionnaire data generally indicate that individuals with ASD exhibit differences in taste reactivity compared to those without ASD. Neuroimaging studies suggest potential involvement of specific brain regions, including hippocampal volume and anterior superior temporal sulcus (aSTS) connectivity in atypical taste processing. Psychophysical assessments and animal studies further reveal variability in basic taste preferences, with individuals with ASD showing particular aversion to bitterness and showing either no difference or a decreased preference for sweetness compared to typically developing peers. This review also highlights research gaps regarding specific qualitative tastes such as saltiness, sourness, and umami in ASD, limiting a comprehensive understanding of ASD's chemosensory profile and emphasizing the need for further research in these areas.

Nutritional Factors and Therapeutic Interventions in Autism Spectrum Disorder: A Narrative Review

Objective: To explore recent findings on how nutritional, gastrointestinal, social, and epigenetic factors interact in autism spectrum disorder, highlighting their implications for clinical management and intervention strategies that could improve development and quality of life of affected children. Sources: Studies published from 2000 to 2024 in the PubMed, Web of Science, Scopus, Scielo, Lilacs, and Google Scholar databases were collected. The process for the review adhered to the Search, Appraisal, Synthesis, and Analysis framework. Summary of the findings: Children with autism spectrum disorder have restrictive eating habits and often exhibit food selectivity with either hyper- or hypo-sensory characteristics. This review provides an overview of the literature on diagnosis and intervention strategies for selectivity in autism spectrum disorder, including the involvement of family members in meals, sharing a healthy diet and positive relationship with food, and the importance of exploring visual, olfactory, and tactile experiences of food and introducing new foods through play activities to expand the food repertoire. Modifications in the microbiota and gastrointestinal disorders may also be present in autism spectrum disorder and are presented due to their frequent nutritional repercussions. The medium and long-term implications of food preferences and behavior issues for nutritional status are also discussed, given the tendency for children with autism spectrum disorder to consume low-quality and energy-dense foods, leading to nutritional problems. Conclusions: Children with autism spectrum disorder have feeding difficulties, especially selectivity, gastrointestinal problems, changes in the microbiota and can evolve with micronutrient deficiencies, malnutrition and obesity. This review describes the evidence for possible targets for interventions aiming to improve nutritional health for children with autism spectrum disorder.

Comparing eating and mealtime experiences in families of children with autism, attention deficit hyperactivity disorder and dual diagnosis

LAY ABSTRACT

Children with neurodevelopmental conditions like autism and attention deficit hyperactivity disorder may experience eating difficulties and related health issues later in life. Sharing family meals can help prevent these issues developing, but most studies have looked at families with neurotypical children. Our goal was to learn more about how families of children with autism, attention deficit hyperactivity disorder and both conditions (autism + attention deficit hyperactivity disorder) experience mealtimes. We developed an online survey asking caregivers about their child's eating, mealtime experience and if they experienced stress. We tested it with nine caregivers and made improvements based on their feedback before recruiting 351 caregivers to complete the main survey. We found that families of children with neurodevelopmental conditions experienced greater food fussiness, emotional undereating, 'problematic' child mealtime behaviours, dietary concerns, higher stress for caregivers and spouses and less frequent conventionally structured mealtimes compared to those without these conditions. Families of children with attention deficit hyperactivity disorder and autism + attention deficit hyperactivity disorder reported greater appetite, 'problematic' mealtime behaviours and increased stress for caregivers and spouses compared to families of children with autism. Meanwhile, families of children with autism and autism + attention deficit hyperactivity disorder reported less enjoyment of food and less structured mealtimes compared to those with attention deficit hyperactivity disorder. Our findings highlight that families of children with neurodevelopmental conditions, particularly those with autism + attention deficit hyperactivity disorder, have different mealtime experiences and eating behaviours compared to those with neurotypical children. These families may benefit from support at mealtimes. Learning why people do or do not participate in shared family meals will be crucial to developing improved mealtime support in the future.

Recruitment feasibility and dietary and behavioral patterns in toddlers with ASD: Preliminary results from the Autism Eats program

BACKGROUND

Problematic mealtime behaviors and inadequate diet quality are pressing concerns for children with autism spectrum disorder (ASD). This study aimed to evaluate recruitment feasibility and baseline outcomes of the Autism Eats program for children under 3 years with ASD.

METHODS

Recruitment feasibility was assessed through reach and participation rates. The Healthy Eating Index (HEI-2015) scores were calculated from 3-day food records. Problematic mealtime behaviors were assessed with the Brief Autism Mealtime Behavior Inventory. Parental feeding practices were assessed using the Child Feeding Questionnaire. Anthropometric measurements of children and parents were taken. Weight-for-length percentiles were calculated based on the CDC growth charts. Descriptive statistics, one-sample t-tests, and Spearman's rho correlations were used for data analysis.

RESULTS

Of the contacted dyads, 74 % agreed to participate. All 51 enrolled dyads completed baseline survey (100 %), and 98 % completed 3-day food records and anthropometric measurements. Significantly higher problematic mealtime behaviors were observed, compared to the reference (e.g., Total score 55.7 vs. 32.5; p < .001). Children with ASD exhibited lower HEI-2015 scores than national data (e.g., Total score 59 vs. 62). A large proportion of the children (29 %) had a weight-for-length ≥ 95th percentile. Several significant associations were found among mealtime behaviors, diet quality, parental feeding practices, and weight status.

CONCLUSION

Recruitment was highly feasible, and the findings suggest that early nutrition intervention may hold promise in addressing problematic mealtime behaviors and promoting healthier dietary habits in young children with ASD.

CLINICAL TRIAL REGISTRATION

This trial has been registered at www.

CLINICALTRIALS

gov (NCT05194345).

Exploring Dietary Interventions in Autism Spectrum Disorder

Autism spectrum disorder (ASD) involves social communication difficulties and repetitive behaviors, and it has a growing prevalence worldwide. Symptoms include cognitive impairments, gastrointestinal (GI) issues, feeding difficulties, and psychological problems. A significant concern in ASD is food selectivity, leading to nutrient deficiencies. Common GI issues in ASD, such as constipation and irritable bowel syndrome, stem from abnormal gut flora and immune system dysregulation. Sensory sensitivities and behavioral challenges exacerbate these problems, correlating with neurological symptom severity. Children with ASD also exhibit higher oxidative stress due to low antioxidant levels like glutathione. Therapeutic diets, including ketogenic, high-antioxidant, gluten-free and casein-free, and probiotic-rich diets, show potential in managing ASD symptoms like behavior, communication, GI issues, and oxidative stress, though the evidence is limited. Various studies have focused on different populations, but there is increasing concern about the impact among children. This review aims to highlight the food preferences of the ASD population, analyze the effect of the physicochemical and nutritional properties of foods on the selectivity in its consumption, GI problems, and antioxidant deficiencies in individuals with ASD, and evaluate the effectiveness of therapeutic diets, including diets rich in antioxidants, gluten-free and casein-free, ketogenic and essential fatty acids, and probiotic-rich diets in managing these challenges.

Feeding-Related Early Signs of Autism Spectrum Disorder: A Narrative Review

Feeding difficulties are prevalent among individuals with autism spectrum disorder (ASD). Nevertheless, the knowledge about the association between feeding-related early signs and child development remains limited. This review aimed to describe the signs and symptoms related to feeding during child development and to explore their relevance to the diagnosis of ASD. Specialists in nutrition and/or ASD conducted a search of MEDLINE, PsycINFO, and Web of Science databases. Although studies in typically developing children demonstrate age-related variations in hunger and satiety cues, the literature about early feeding indicators in ASD is scarce. Challenges such as shortened breastfeeding duration, difficulties in introducing solid foods, and atypical mealtime behaviors are frequently observed in children with ASD. The eating difficulties experienced during childhood raise concerns for caregivers who base their feeding practices on their perceptions of food acceptance or refusal. Considering the observed associations between feeding difficulties and ASD, the importance of recognizing feeding-related signs according to developmental milestones is emphasized to alert medical professionals that deviation in the formation of feeding habits and skills could indicate the need for ASD diagnostic investigation.

Social communication and restricted, repetitive behavior as assessed with a diagnostic tool for autism (ADOS-2) in women with anorexia nervosa

OBJECTIVE

In anorexia nervosa (AN), the traits of autism spectrum disorder (ASD) are associated with poor outcomes. However, the subtle nature of these characteristics remains poorly understood. We investigated the in-depth patterns of ASD traits using Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) in women with AN.

METHODS

Of 28 women with ICD-10 AN, 16 (age 19-30 years) participated in the ADOS-2, a video-recorded, semistructured diagnostic assessment for social communication and interaction and restricted, repetitive behaviors and interests related to ASD. None of the participants had previously been diagnosed with ASD. Other measurements included the Eating Disorder Examination Questionnaire and the Wechsler Abbreviated Scale of Intelligence-IV.

RESULTS

Five individuals (18% of all, 31% of those assessed) scored above the cutoff for autism in ADOS-2. They had challenges in social communication and interaction, manifesting as sustained difficulties in social relationships and deficits in conversation skills. Few described being frequently misunderstood by others, including in the eating disorder treatment settings. Three individuals showed prominent restricted and repetitive behaviors such as ritual seeking, eating-related routines, sensory sensitivity related to food texture and selective eating, and intense interest in specific topics. The mean duration of AN in women above the cutoff was twice as long compared with those below (12.3 vs. 6.2 years).

DISCUSSION

The ASD-related characteristics and behavior appear to contribute to the manifestation and duration of AN in a subgroup of women. Among these women, the traits of ASD appear to be mixed with eating disorder symptoms, which should be taken into account in the treatment.

Neophobia, sensory experience and child's schemata contribute to food choices

PURPOSE

The aim of the present review is to analyze dynamic interactions between nutrigenomics, environmental cues, and parental influence, which can all lead to children's neophobic reactions and its persistence in time.

METHODS

We reviewed studies available on electronic databases, conducted on children aged from birth to 18 years. We also considered official websites of Italian Institutions, providing advice on healthy eating during infancy.

RESULTS

Modern day societies are faced with an eating paradox, which has severe and ever-growing implications for health. In face of a wider availability of healthy foods, individuals instead often choose processed foods high in fat, salt and sugar content. Economic reasons surely influence consumers' access to foods. However, there is mounting evidence that food choices depend on the interplay between social learning and genetic predispositions (e.g., individual eating traits and food schemata). Neophobia, the behavioral avoidance of new foods, represents an interesting trait, which can significantly influence children's food refusal. Early sensory experiences and negative cognitive schemata, in the context of primary caregiver-child interactions, importantly contribute to the priming of children's food rejection.

CONCLUSIONS

As neophobia strongly affects consumption of healthy foods, it will be relevant to rule definitively out its role in the genesis of maladaptive food choices and weight status in longitudinal studies tracking to adulthood and, in meanwhile, implement early in life effective social learning strategies, to reduce long-term effects of neophobia on dietary patterns and weight status.

LEVEL OF EVIDENCE

Level II, controlled trials without randomization.

Associations between genetically determined dietary factors and risk of autism spectrum disorder: a Mendelian randomization study

Background

Existing studies confirm the importance of dietary factors in developing autism spectrum disorder (ASD) and disease progression. Still, these studies are primarily observational, and their causal relationship is unknown. Moreover, due to the extensive diversity of food types, the existing research remains somewhat limited in comprehensiveness. The inconsistency of the results of some studies is very disruptive to the clinic. This study infers a causal relationship between dietary factors on the risk of developing ASD from a genetic perspective, which may lead to significant low-cost benefits for children with ASD once the specificity of dietary factors interfering with ASD is confirmed.

Methods

We performed a two-sample Mendelian randomization (MR) analysis by selecting single nucleotide polymorphisms (SNPs) for 18 common dietary factors from the genome-wide association study (GWAS) database as instrumental variables (IVs) and obtaining pooled data for ASD (Sample size = 46,351) from the iPSYCH-PGC institution. Inverse variance weighted (IVW) was used as the primary analytical method to estimate causality, Cochran's Q test to assess heterogeneity, the Egger-intercept test to test for pleiotropy and sensitivity analysis to verify the reliability of causal association results.

Results

The MR analysis identified four dietary factors with potential causal relationships: poultry intake (fixed-effects IVW: OR = 0.245, 95% CI: 0.084-0.718, P < 0.05), beef intake (fixed-effects IVW: OR = 0.380, 95% CI: 0.165-0.874, P < 0.05), cheese intake (random-effects IVW: OR = 1.526, 95% CI: 1.003-2.321, P < 0.05), and dried fruit intake (fixed-effects IVW: OR = 2.167, 95% CI: 1.342-3.501, P < 0.05). There was no causal relationship between the remaining 14 dietary factors and ASD (P > 0.05).

Conclusion

This study revealed potential causal relationships between poultry intake, beef intake, cheese intake, dried fruit intake, and ASD. Poultry and beef intake were associated with a reduced risk of ASD, while cheese and dried fruit intake were associated with an increased risk. Other dietary factors included in this study were not associated with ASD.

Programmes to manage food selectivity in individuals with autism spectrum disorder

Autism spectrum disorder (ASD) is a complex group of neurodevelopmental disorders characterised by impaired social communication and restricted interests/repetitive behaviours. In this regard, sensory processing difficulties and delayed oral motor skills often predispose individuals with ASD to food selectivity (FS). It is usually associated with repetitive eating patterns that can lead to multiple malnutrition conditions. The objective of this narrative review is to present an overview about the existing nutritional interventions aiming at promoting a healthy eating pattern and addressing food selectivity among individuals with ASD. Regarding the interventions targeting nutrition education, the majority of the analysed studies failed to demonstrate their effectiveness. On the other hand, many educational interventions involving taste or cooking sessions, as well as behavioural interventions for FS, demonstrated effective results. Moreover, multidisciplinary in tailoring such programmes, including psychology speech therapy and nutritional skills, is acknowledged as a key approach.

Autism Spectrum Disorder and Eating Problems: The Imbalance of Gut Microbiota and the Gut-Brain Axis Hypothesis

This review explores the complexities of autism spectrum disorder (ASD), primarily focusing on the significant eating challenges faced by children and adolescents with this neurodevelopmental condition. It is common for individuals with ASD to exhibit heightened sensitivity to various sensory aspects of food such as taste, texture, smell, and visual appeal, leading to restricted and less diverse diets. These dietary limitations are believed to contribute to an imbalance in the gut microbiota. This review elaborates on how these eating problems, coupled with the distinctive characteristics of ASD, might be influenced by and, in turn, influence the gut-brain axis, a bidirectional communication system between the gastrointestinal tract and the brain. This discussion aims to shed light on the multifaceted interactions and potential implications of diet, gut health, and neurological development and function in children and adolescents with ASD.