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.