The importance of nutrition during the first six years of life in children with autism spectrum disorder: Feeding difficulties, nutrient deficiencies, and early intervention approaches

Abstract

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition that emerges in early childhood and is characterized by differences in social interaction and communication, as well as restricted and repetitive patterns of behavior, interests, or activities. The core features of ASD may be accompanied by differences in sensory processing, various feeding difficulties, and gastrointestinal symptoms. The first six years of life represent a critical developmental period during which all domains of development progress rapidly. During this period, physical growth, neurodevelopment, eating habits, and independent feeding skills undergo substantial development. Children with ASD commonly exhibit food selectivity, a limited food repertoire, refusal of novel foods, sensitivities to specific tastes, odors, textures, colors, or temperatures, and challenging behaviors during mealtimes. Evidence suggests that these feeding-related characteristics are particularly associated with sensory processing differences and behavioral features. Severe food selectivity may also be accompanied by reduced dietary diversity and inadequate nutrient intake in some children. This study aims to examine the importance of nutrition during early childhood in children with ASD, with particular emphasis on early feeding behaviors, food selectivity, sensory processing, nutritional adequacy, and early feeding interventions, based on the current scientific literature. In addition, the limitations of the available evidence regarding currently debated nutritional approaches, such as probiotics and gluten-free/casein-free diets, are evaluated, and the importance of family-centered, individualized, and multidisciplinary early intervention is discussed.