Dietary Antioxidant Capacity and Feeding Problems in Children with Autism Spectrum Disorder: Relationships with Growth and Gastrointestinal Symptoms

Abstract

Objectives: To examine dietary total antioxidant capacity (TAC) and feeding problems in children with autism spectrum disorder (ASD), and their relationships with anthropometric measures and gastrointestinal (GI) symptoms. Methods: Cross-sectional study in urban developmental centers. Of 60 recruited children (4–12 y) with ASD, 53 were analyzed (7 excluded for incomplete diet/GI data). Diet was assessed using a semi-quantitative FFQ and a 24-h recall. TAC (mmol/day) was estimated by mapping FFQ items to a FRAP-indexed antioxidant database and aggregating item-level values; nutrient adequacy was expressed as % of age/sex-specific TÜBER-2022 recommendations. Anthropometry was converted to WHO BMI-for-age z-scores; GI symptoms were parent-reported. Statistics included sex comparisons, correlations, and multivariable models adjusting for age, sex, and parental education. Results: Mean TAC was 2.72 ± 1.40 mmol/day (no sex difference, p = 0.655). Frequent feeding problems included refusal of new foods (60.6%), food selectivity (39.3%), and pica (33.3%). Median adequacy was < 50% for vitamin D, vitamin E, and iron. GI symptoms were common (constipation 22.6%, abdominal pain 28.3%). In adjusted models, higher TAC was associated with healthier BMI z-scores and lower odds of constipation (effect sizes to be inserted after re-analysis). Conclusions: Suboptimal antioxidant intake and prevalent feeding problems co-occur with GI symptoms in Turkish children with ASD. Findings are associative, supporting targeted, culturally adapted strategies to increase antioxidant-rich foods and fiber while addressing feeding difficulties. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.