Food selectivity and eating difficulties in adults with autism and/or ADHD

Children with autism or attention-deficit/hyperactivity disorder (ADHD) are more likely than neurotypical children to experience eating difficulties, such as picky/selective eating, slow eating, and over/under-eating. Recent studies show that eating difficulties can persist into adulthood for autistic individuals. Yet little is known about the mechanisms involved and whether adults with ADHD also experience such challenges. We (1) compare eating difficulties among adults with autism, ADHD, autism/ADHD, and neither condition and (2) identify predictors of overall eating pathology and of food selectivity. The sample was 50% female and 78% White, consisting of 961 adults aged 19-57 who self-reported their diagnostic status: 184 with autism, 416 with ADHD, 292 with autism/ADHD, and 69 comparisons. Eating difficulties were assessed via self-report survey using the Swedish Eating Assessment for Autism (SWEAA) and Food Preferences Questionnaire. Autistic adults, with or without ADHD, reported significantly more eating difficulties than all other groups. Total eating difficulties were associated with increased insistence on sameness, other autistic features, food selectivity, and hyperactivity-impulsivity. Food selectivity was predicted by increased insistence on sameness, sensory sensitivity, and other core features of autism, and lower hyperactivity-impulsivity. The high degree of eating difficulties in autistic adults warrants clinical attention on this topic.Lay Abstract Some people do not like many foods, eat very quickly or slowly, or eat too much or too little. These problems are more common in children with autism or ADHD and may continue for a long time, but we do not know much about these problems in adults. Our goal was to understand how eating difficulties are similar and different in adults with autism, ADHD, both autism/ADHD, and neither condition. We also wanted to understand factors that relate to picky eating and overall eating difficulties. We found that autistic adults had the most problems with eating compared to all other groups. Adults with ADHD had more eating problems than adults with neither condition. Adults with autism and/or ADHD were more sensitive to taste and texture of foods, had difficulty with spilling food, and found it hard to tell whether they are hungry or full compared to people without these conditions. We also found that autism and ADHD traits were linked to picky eating and having more eating problems. The results show that many autistic adults and some with ADHD might need support with eating. Doctors should pay attention to eating problems to help people get the care they need. Results also show that wanting things to stay the same may be more related to eating problems than researchers previously thought. We need more research to understand how to support adults with eating difficulties.