This study aims to investigate the effects of the SOS approach alone, or the SOS approach plus the OPC intervention, on children's feeding problems and feeding behaviors, as well as parents' feeding attitudes and mealtime behaviors in children diagnosed with ARFID. This randomized, single-blind, controlled trial will be conducted with children aged 3-8 years who were diagnosed with ARFID by a Child and Adolescent Psychiatrist according to DSM-V criteria and referred to an occupational therapy department. Power analysis determined the sample size to be 45 children (15 per group). Participants will be assigned to three groups using computer-assisted block randomization: Group 1: Sequential Oral Sensory (SOS) Feeding Approach alone; Group 2: SOS approach plus Occupational Performance Coaching (OPC); and Group 3: Control group (standard follow-up without intervention). The study design will utilize the Consort checklist used for randomized controlled trials. Informed consent will be obtained from participants. Pre- and post-intervention assessments will be conducted on the child's feeding behaviors, food variety, and mealtime negative behaviors, as well as parental feeding attitudes, mealtime behaviors, and stress. The study concludes that feeding interventions implemented using the SOS approach will be effective in reducing food acceptance, food variety, and mealtime negative behaviors in children with ARFID. These effects are expected to be more pronounced and sustained when Occupational Performance Coaching (OPC) is added to the SOS approach. Furthermore, positive changes in parents' feeding attitudes and strengthened parent-child interactions at mealtime are anticipated. These results will contribute to the literature on the effectiveness of using sensory-based approaches and family-based counseling in combination in interventions for ARFID. They are also expected to provide an evidence-based roadmap for occupational therapists to develop holistic intervention programs when working with children with ARFID in clinical practice.

Avoidant/Restrictive Food Intake Disorder (ARFID), defined and included in the diagnostic categories with the publication of the Diagnostic and Statistical Manual of Mental Disorders - Fifth Edition (DSM-5) by the American Psychiatric Association, is a serious disorder related to feeding behavior. According to DSM-5, ARFID is characterized by one or more of the following criteria: significant weight loss (or failure to achieve expected weight gain/growth in children), marked nutritional deficiencies, dependence on enteral feeding or oral nutritional supplements, and/or marked impairment in psychosocial functioning. This condition differs from culturally normative fasting or attempts to lose weight and is not associated with a fear of body shape or weight.

In children with ARFID, food selectivity, insufficient food intake, and intense negative emotions related to feeding are observed. This disorder not only leads to weight loss and growth retardation but also significantly affects children's daily life activities, family life, and social interactions.

ARFID has a prevalence rate of 3.2% in the general pediatric population. It has been reported that the proportion of males is higher in ARFID diagnoses and that, compared to other DSM-5 eating disorders, it is more frequently associated with comorbid psychiatric and/or medical conditions. However, ARFID is a heterogeneous condition that includes individuals ranging from young children to adults. Prevalence estimates for ARFID vary widely depending on the population and setting examined. A systematic review found that in non-clinical child and adolescent samples, estimated prevalence rates for ARFID ranged between 0.3% and 15.5%. The prevalence has been reported as 64% among infants and young children, and 15.5% among children aged 5-10 years.

To date, most research on ARFID treatment has focused on psychological interventions, which typically include psychoeducation, exposure, and cognitive-behavioral therapy, family-based treatment, or applied behavior analysis approaches. Occupational therapists assess and address feeding difficulties by considering sensory differences, physical and cognitive impairments, as well as broader contextual factors such as social environments, mealtime rituals and routines, culture, and social factors. It has been emphasized that occupational therapy interventions are needed for individuals with ARFID. Occupational therapists have demonstrated effectiveness using approaches such as the Sequential Oral Sensory (SOS) Feeding Approach, Sensory Integration, the Just Right Challenge Feeding Protocol, and family-based programs such as Occupational Performance Coaching (OPC). Studies highlight the need to standardize occupational therapy approaches for ARFID and to conduct single-case experimental designs and randomized controlled trials comparing these approaches with alternative methods.

In this context, the Sequential Oral Sensory (SOS) Feeding Approach is a structured intervention that supports sensory-motor skills related to feeding and aims to help the child develop a positive relationship with food. By gradually increasing interaction with food, the SOS approach aims to reduce sensory sensitivities and improve feeding behaviors. It has been shown to be effective particularly in children with autism spectrum disorder and in other diagnostic groups with feeding difficulties. However, no randomized controlled trial has yet been found addressing the use of this approach in children with ARFID.

On the other hand, Occupational Performance Coaching (OPC) is a structured, problem-solving, guidance, and empowerment-based approach designed to help parents support their children's daily life performance. Studies conducted with families of children with developmental differences have shown that OPC contributes positively to parental self-efficacy, stress levels, and children's participation levels. While studies have demonstrated its effectiveness in children with selective eating problems, it has been emphasized that its effectiveness should be further tested in randomized controlled trials.

Despite existing psychosocial interventions for ARFID, the literature highlights a lack of sensory- and behaviorally-oriented feeding interventions. Therefore, this randomized controlled single-blind study aims to examine the effects of the SOS approach alone and in combination with OPC on feeding problems and feeding behaviors of children with ARFID, as well as on parental feeding attitudes and mealtime behaviors. By going beyond child-focused sensory-based interventions, this study also evaluates the effectiveness of family-centered approaches. The study aims to make an original contribution to the development of applicable and effective intervention models for children and families dealing with ARFID, both at the clinical and societal levels.

Inclusion Criteria:

• Inclusion Criteria (for the child):

  • Having been diagnosed with ARFID according to the DSM-5 by a Child and Adolescent Mental Health and Diseases psychiatrist (Assoc. Prof. Dr. Hakan ÖĞÜTLÜ).
  • Being between the ages of 3 and 8.
  • Being medically stable for outpatient treatment.
  • Having no conditions (visual, auditory, cognitive, or chewing) that would prevent participation in treatment.

Inclusion Criteria (for the mother):

• Being the child's primary caregiver and living with the mother.
• Having at least a primary school diploma and possessing Turkish reading and comprehension proficiency.
• Agreeing to take an active role in the intervention process and participate in research evaluations.
• Being a regular participant in the child's feeding process.
• Not having another child with special needs.

Exclusion Criteria:

• Exclusion Criteria (Child):

  • History of comorbid neurological, genetic, psychiatric, or metabolic disease
  • Child and family receiving other individual or family-based education and/or psychotherapy during the intervention
  • Taking medication for comorbid disorders affecting appetite and/or weight
  • Active psychiatric crisis (e.g., severe anxiety disorder, post-traumatic stress disorder)
  • Significant family or environmental constraints that would prevent regular attendance

Exclusion Criteria (Mother):

• Severe hearing, vision, or cognitive impairment
• Child concurrent participation in another intervention program (dietician, psychotherapy, group education, etc.) related to feeding behaviors
• Presence of a chronic health condition (e.g., neurological, psychiatric, orthopedic, oncological, etc.) that would prevent regular attendance at the intervention

We plan to share individual participant data (IPD) that underlie the results reported in published articles, including de-identified demographic characteristics, baseline assessments, outcome measures, and intervention-related data. All shared IPD will be fully anonymized to ensure participant confidentiality.

Individual participant data (IPD) and supporting documents will be available starting 6 months after publication of the primary study results and will remain accessible for 5 years thereafter.

De-identified individual participant data (IPD) and supporting documents will be available to qualified researchers from academic institutions, hospitals, or recognized research organizations. Data will be shared only for projects with a sound scientific rationale and an established analysis plan. Researchers must submit a formal request describing study aims, methodology, and data protection procedures. Access will be granted through a secure, password-protected platform managed by the sponsor. Approved researchers will be required to sign a data use agreement to ensure confidentiality, proper use of the data, and compliance with ethical and legal standards.

The single-blind method in this study is based on the principle that the experts conducting the evaluations are unaware of the group assignment; thus, the measurement results will be evaluated independently of the intervention information. While the intervention implementers have knowledge of the groups, analysts during the data analysis phase will be blinded to the groups.