Development and Risk Factors

ARFID does not appear from nowhere. It develops through the interaction of biological predispositions, temperamental traits, neurodevelopmental conditions, specific triggering events, and environmental factors that either buffer against or amplify the disorder. Understanding these pathways matters for both the person with ARFID and their family, because it clarifies what caused the condition, what maintains it, and what the likely trajectory looks like without intervention.

Genetics

Twin studies provide the strongest evidence for genetic contribution to ARFID. A landmark study by Dinkler and colleagues (2023) using a large twin sample estimated the heritability of ARFID at 0.79. This means that approximately 79 percent of the variation in ARFID risk can be attributed to genetic factors.

To put that number in context, 0.79 is a high heritability estimate, comparable to conditions like autism and ADHD. It firmly establishes ARFID as a biologically grounded condition rather than a behavioral choice or parenting outcome.

The specific genes involved are not yet fully mapped, but the high heritability suggests that the neurological differences underlying ARFID, including heightened sensory reactivity, reduced interoceptive awareness, and anxiety-prone temperament, are substantially inherited. If ARFID runs in your family, this genetic loading is the most likely explanation.

Temperamental Risk Factors

Certain temperamental traits present from early childhood increase the likelihood of developing ARFID.

Behavioral inhibition. Children who are temperamentally cautious, slow to approach new situations, and prone to withdrawal in the face of novelty are at elevated risk. Food neophobia (fear of new foods) is a normal developmental phase, but in behaviorally inhibited children it tends to be more intense and more persistent.

Sensory sensitivity. Children who show broad sensory sensitivity, reacting strongly to loud noises, certain fabrics, bright lights, and other non-food stimuli, are more likely to develop sensory-based food avoidance. The same neural wiring that makes tags in clothing intolerable can make certain food textures unacceptable.

Anxiety proneness. A general tendency toward anxiety, whether or not it meets criteria for a formal anxiety disorder, creates fertile ground for fear-based ARFID. Anxious temperament amplifies the threat signal associated with negative eating experiences and makes generalization of avoidance more likely.

Low appetite from birth. Some infants show reduced appetite and feeding difficulties from the earliest weeks of life, suggesting that the biological substrate for low-interest ARFID is present before any environmental influence.

Neurodevelopmental Conditions

ARFID co-occurs with several neurodevelopmental conditions at rates well above chance.

Autism spectrum disorder. As detailed in Module 4, the overlap is substantial (16.27 percent prevalence in autistic individuals). Sensory processing differences, need for sameness, and interoceptive atypicalities all contribute.

ADHD. Attention-deficit/hyperactivity disorder intersects with ARFID through multiple pathways. Executive function difficulties can impair meal planning and preparation. Stimulant medications commonly used to treat ADHD suppress appetite, potentially initiating or worsening low-interest ARFID. Impulsivity and novelty-seeking, paradoxically, can coexist with rigid food preferences when sensory sensitivity is also present.

Intellectual disability. Individuals with intellectual disability have elevated rates of feeding difficulties including ARFID, though diagnostic clarity can be complicated by communication challenges and the tendency to attribute eating problems to the primary diagnosis.

Anxiety disorders. Generalized anxiety, specific phobias, social anxiety, and OCD all co-occur with ARFID at elevated rates. The relationship is bidirectional: anxiety disorders increase risk for fear-based ARFID, and ARFID itself generates anxiety that can crystallize into formal anxiety diagnoses.

Triggering Events

For many people with ARFID, particularly those with the fear-based presentation, there is an identifiable event that initiated the avoidance pattern.

Common triggers include choking episodes, vomiting (whether from illness, food poisoning, or other causes), anaphylactic or allergic reactions, severe abdominal pain, witnessing someone else choke or vomit, and medical procedures involving the throat or GI tract (intubation, nasogastric tubes, endoscopy).

The triggering event does not need to be objectively severe. What matters is how the individual’s nervous system encodes the experience. A single episode of vomiting that would be unremarkable for one child can initiate a cascade of conditioned avoidance in a child with anxious temperament and sensory sensitivity.

Not everyone with ARFID has an identifiable trigger. Sensory-based and low-interest presentations often develop gradually without a discrete precipitating event.

Environmental Amplifiers

While ARFID is not caused by environmental factors, certain environmental responses can amplify and maintain the disorder once it has begun.

Pressure to eat. As discussed in Module 2, pressuring a person with ARFID to eat increases the aversive quality of mealtimes and reinforces avoidance. Well-intentioned insistence (“just try one bite”) paradoxically strengthens the association between eating and distress.

Excessive accommodation. At the other extreme, fully accommodating the restriction without any gentle challenge can cement avoidance patterns. If the environment never presents an opportunity for the person to encounter new foods in a low-pressure way, there is no chance for the neural associations to shift.

Limited food exposure. Environments that offer little variety, whether due to economic constraints, caregiver food preferences, or cultural factors, reduce opportunities for the gradual expansion that might otherwise occur.

Family anxiety around food. When the entire household organizes around the person’s eating restrictions, the implicit message is that food is dangerous and requires careful management. This family-level anxiety can reinforce the individual’s own threat associations.

Social reinforcement of avoidance. Peers, teachers, and extended family members who make a person with ARFID feel different or defective around food can drive social avoidance that compounds the eating-specific avoidance.

Trajectory Without Treatment

Understanding the natural course of ARFID without intervention provides important context for treatment decisions. A longitudinal study by Kambanis and colleagues (2024) followed individuals with ARFID over a two-year period and found sobering results.

At the two-year mark, 44 to 46 percent of participants still met full diagnostic criteria for ARFID. Only 24 to 26 percent had achieved remission. The remainder had partial improvement but continued to experience clinically significant symptoms.

These numbers contradict the common reassurance that restrictive eating is something children grow out of. While mild picky eating often does resolve developmentally, clinical ARFID persists in the majority of cases without targeted treatment. The data argues strongly for early intervention rather than watchful waiting.

The trajectory also varies by presentation. Fear-based ARFID may be somewhat more responsive to treatment due to the availability of well-established anxiety treatment protocols. Sensory-based ARFID, particularly when co-occurring with autism, may follow a more chronic course that requires longer-term management and accommodation alongside gradual expansion.