Recent twin research reveals a high heritability of avoidant restrictive food intake disorder (ARFID), pointing to genetic factors that overlap with autism and ADHD, but underscores that environment and early intervention remain crucial.
Parents often see the pattern before anyone has a name for it: a child who eats only a narrow set of foods, a relative who still refuses certain textures and a family history that makes the pattern feel less random. In the case of avoidant restrictive food intake disorder, or ARFID, researchers now have stronger reason to think that inherited risk plays an important role, even though it is never the whole story.
A 2023 twin study published in JAMA Psychiatry estimated the heritability of the ARFID phenotype at 79%, based on nearly 17,000 twin pairs in Sweden. A separate study from Sweden found the same headline figure, with non-shared environmental factors accounting for the rest of the risk. Together, the findings suggest that genes matter a great deal, but they do not make the diagnosis inevitable.
That distinction matters because heritability describes variation across a population, not a fixed fate for an individual child. ARFID is a clinically recognised feeding and eating disorder marked by persistent restriction that can lead to poor growth, nutritional deficiencies, reliance on supplements or serious disruption to daily life. Unlike anorexia nervosa, it is not driven by body image or fear of weight gain.
Researchers think the genetic contribution shows up through several pathways rather than a single ARFID gene. Sensory sensitivity, appetite regulation, anxiety and neurodevelopmental traits all appear to raise risk. A preprint using Swedish twin data found substantial genetic overlap between broad ARFID traits and autism and ADHD, supporting the idea that some children inherit a broader neurodevelopmental vulnerability that can make restrictive eating more likely.
Evidence from autism research points in the same direction. A study in a large autism cohort found that a notable share of parents of autistic children were themselves at heightened risk for ARFID and identified a possible genetic signal near the ZSWIM6 gene, which has also been linked to neurodevelopmental conditions. That does not prove a direct cause, but it strengthens the case that ARFID often sits within a wider inherited pattern of sensory, behavioural and developmental differences.
Family resemblance, however, is not only about DNA. Households also share food routines, anxiety around meals and the everyday habits that shape how children learn to eat. That is one reason specialists stress early evaluation when eating becomes progressively narrower, especially if there is a family history of selective eating, anxiety, autism or ADHD. ARFID is diagnosed clinically, not through a genetic test, and treatment usually combines medical monitoring, dietetic support, psychological therapy and, when needed, occupational therapy.
The larger research effort is only beginning. The ARFID-GEN study, a U.S. project designed to enrol thousands of children and adults, is aiming to map the disorder’s genetic and environmental architecture more precisely. For families, the practical message is already clearer: inherited traits may load the dice, but they do not write the ending.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
