Background: ARFID (avoidant restrictive food intake disorder) is a relatively new diagnostic term covering a number of well-recognised, clinically significant disturbances in eating behaviour unrelated to body weight/shape concerns. Its phenotypic heterogeneity combined with much about the condition remaining unknown, can contribute to uncertainties about best practice. While other reviews of the evidence base for ARFID exist, few specifically target health care professionals and implications for clinical practice.Methods: A narrative review was conducted to synthesise the findings of ARFID papers in scientific journals focussing on four key areas relevant to clinical practice: prevalence, assessment and characterisation of clinical presentations, treatment, and service delivery. Freely available online databases were searched for case studies and series, research reports, review articles, and meta-analyses. Findings were reviewed and practice implications considered, resulting in proposed clinical recommendations and future research directions. Results:We discuss what is currently known about the four key areas included in this review. Based on available evidence as well as gaps identified in the literature, recommendations for clinical practice are derived and practice-related research priorities are proposed for each of the four of the areas explored. Conclusion:Prevalence studies highlight the need for referral and care pathways to be embedded across a range of health care services. While research into ARFID is increasing, further studies across all areas of ARFID are required and there remains a pressing need for guidance on systematic assessment, evidence-based management, and optimal service delivery models. Informed clinical practice is currently predominantly reliant on expert consensus and small-scale studies, with ongoing routine clinical data capture, robust treatment trials and evaluation of clinical pathways all required. Despite this, a number a positive practice points emerge.

Importance Avoidant restrictive food intake disorder (ARFID) is a newly recognised eating disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and in the International Classification of Diseases, Eleventh Revision which shows great heterogeneity in its clinical presentation. Objectives Here, we examined the clinical characteristics of ARFID and explored the associations between ARFID symptoms and traits of anxiety. We also investigated whether individuals with ARFID show a different clinical presentation based on their biological sex or comorbid autism spectrum disorder (ASD) diagnosis. Design, Setting, and Participants We recruited 261 consecutive patients from the specialised ARFID outpatient service at the Maudsley Centre for Child and Adolescent Eating Disorders, Michael Rutter Centre, Maudsley Hospital, London, United Kingdom. Main Outcomes and Measures The parents of the patients completed the Pica, ARFID, Rumination Disorder - ARFID - Questionnaire (PARDI-AR-Q), the Revised Children's Anxiety and Depression Scale (RCADS) and reported biological sex of their offspring. Age, height, and weight were obtained from medical records. Clinicians reported on comorbid ASD diagnosis and anxiety traits using the Current View Tool. Results This cross-sectional study included 261 child and adolescent ARFID patients (133 [51%] female) with a median age of 12.7 years (IQR=9.2 to 15.8). Patients' BMI-for-age z-scores ranged from -6.75 to 4.07 (median = -1.07, IQR = -2.25 to -0.01). Patients' comorbid traits of anxiety had the highest correlations with symptoms on the concern about aversive consequences driver of ARFID: panic disorder correlated with physical feelings of panic and anxiety when eating (r=0.53, p=7.74 x 10-31) and being afraid to eat (r=0.42, p=5.13 x 10-21); generalised anxiety correlated with physical feelings of panic and anxiety when eating (r=0.44, p=7.72 x 10-23); and separation anxiety correlated with avoiding eating situations (r=0.36, p=2.01 x 10-15). Sensory sensitivity to the appearance of food positively correlated with separation anxiety (r=0.40, p=1.52 x 10-16) and generalised anxiety (r=0.36, p=7.16 x 10-18). The sensory sensitivities (RR = 0.96; 95% CI, 0.85 to 1.09; P = .53), lack of interest (RR = 1.14; 95% CI, 1.03 to 1.28; P = .02) and concern about aversive consequences (RR = 1.27; 95% CI, 1.03 to 1.56; P = .03) drivers were independent of patient sex. Comorbid ASD was reported in 74 (28%) ARFID patients. Their parents reported higher rates of food-related sensory sensitivities (RR = 1.26; 95% CI, 1.09 to 1.45; P=0.002) and lack of interest (RR = 1.19; 95% CI, 1.05 to 1.34; P=0.006) driving their child's avoidant and restrictive eating than parents of ARFID patients without ASD (127 [49%]). Conclusions and Relevance Our study highlights that ARFID patients present with varying combinations and severity of food-related sensory sensitivities, lack of interest and concern about aversive consequences which drive their avoidant and restrictive eating. ARFID does not discriminate between male and female children and adolescents or those with or without ASD. Anxiety and ASD can co-occur with ARFID, and ASD may accentuate food-related sensory sensitivities and lack of interest. Healthcare professionals should be aware of the multi-faceted and heterogenous nature of ARFID; it is important that comprehensive multidisciplinary assessments are administered to sufficiently understand the drivers of the eating behaviour and associated physical health, nutritional, and psycho-social risk and impact.