ARFID is not the same as being a “picky eater” and the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) defines clear criteria for diagnosing ARFID.
For a diagnosis of ARFID, a restrictive diet must be accompanied by either weight loss, inability to gain weight, nutritional deficiencies, overuse or overreliance on food substitutes and supplements, or significant distress that disrupts a person's daily activities. Meeting one or more of these criteria is necessary for diagnosis.[1] Individuals who have a healthy weight or are overweight but have nutritional deficiencies or other symptoms should also be screened for ARFID.[2][3][4]
Medical professionals typically analyze blood and urine samples to check for nutritional deficiencies and to identify biomarkers of other underlying medical conditions. Ruling out other medical or mental health conditions that may better explain the food restriction and/or avoidance behavior is also a diagnostic criterion for ARFID. For instance, if the food restriction stems from body image and weight concerns, the individual cannot be diagnosed with ARFID because these are typical symptoms of other eating disorders like anorexia nervosa or bulimia nervosa. Moreover, medical professionals need to ensure that the food restriction is not due to a lack of access to food or deliberate dieting or fasting for personal or religious reasons because these are regarded as exclusion criteria. [1]
Clinicians use screening tools such as the Pica, ARFID, and Rumination Disorder Interview (PARDI), the Eating Pathology Symptoms Inventory (EPSI), the Eating Disturbances in Youth-Questionnaire (EDY-Q), and the Nine-Item ARFID Screen (NIAS) to differentiate between ARFID and other eating disorders (e.g., anorexia nervosa) and to assess the drivers behind food restriction and/or avoidance, as well as the severity of symptoms.[5][6]
Because ARFID was introduced into the DSM in 2013, it is considered a relatively recent addition. As a result, additional research is needed to further validate the accuracy of screening tools for ARFID. However, despite the need for further validation, these screening tools are currently available to clinicians for diagnosing this disorder.