Avoidant restrictive food intake disorder (ARFID) is a mental health condition in which people who are affected fail to meet the required nutritional and/or energy intake due to avoidance of specific foods or food groups and/or restriction of the amount of food that they consume, leading to a limited and often low-volume diet. Unlike anorexia nervosa or bulimia nervosa, people with ARFID do not avoid or restrict food with the intention of losing weight or due to concerns related to body image, and unlike other eating disorders, ARFID can occur in both children and adults.^[1]

One common reason for food restriction or avoidance in ARFID is a heightened sensitivity to certain aspects of food, such as smell, taste, texture, or appearance. For example, someone may completely avoid a specific vegetable due to its smell or consume it only in very small quantities. Another reason, often stemming from past negative or traumatic experiences, is the fear of consuming certain foods or food categories that may cause discomfort such as stomach cramps, vomiting, choking, or diarrhea. Additionally, people with ARFID may lack interest in food or perceive eating as burdensome.^[1]

Often, people with ARFID are categorized based on the primary driver of food avoidance/restriction (i.e., sensory sensitivity, fear of adverse consequences, lack of interest in food). However, it is important to note that ARFID can differ from person to person, and some people may have more than one factor that contributes to their eating behavior. Additionally, due to the complexity of this disorder and the often associated comorbidities, there may be other reasons beyond the ones mentioned, and this list should not be considered exhaustive.

Due to the heterogeneity of people with ARFID, the combination of signs and symptoms experienced may vary among individuals.

Malnutrition is a common indicator of ARFID and can lead to a wide range of signs and symptoms, which largely depend on the specific foods being avoided and/or restricted. Deficiency in certain nutrients may result in fatigue, tiredness, gut health issues (such as constipation), abnormal heart rhythm, hair loss, or dry skin. Other physical signs commonly associated with ARFID include weight loss, difficulties in reaching expected weight (particularly in children), and the absence or irregularity of menstrual periods in women.^[1]

It is important to acknowledge that individuals with ARFID can also be overweight or maintain a healthy weight despite being affected by the disorder. This situation often occurs when their diet primarily consists of high-energy foods that lack nutritional value. Although their diet may provide sufficient calories to sustain or increase weight, it may lack the essential nutrients necessary for optimal health.^[2][3][4]

Additionally, people with ARFID may experience feelings of distress and anxiety, especially in situations involving food, which can significantly impact their social, academic, and professional lives. For instance, people with ARFID may avoid meeting up with friends or family gatherings out of fear that they will be presented with foods that they struggle to eat.^[5]

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.^[5] 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. ^[5]

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.^[6][7]

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.

Treating patients with ARFID often involves a combination of psychological, behavioral, and medical interventions.

Cognitive behavioral therapy (CBT) has shown positive results in addressing anxiety and fear associated with food consumption, as well as hypersensitivity to the smell, taste, or texture of certain foods. Another promising psychological treatment is a modified version of family-based therapy (FBT), which was originally used for other eating disorders but has been adapted specifically for ARFID. This approach provides support to people with ARFID, as well as their caregivers and family, while fostering recovery within the home environment and reducing tensions within the family unit.^[8][9][2] The effectiveness of these methods should be further investigated through randomized controlled studies.

People with ARFID, particularly children who don’t ingest enough calories, may also require supplementation with nutritional formulas, oral supplements, or tube feeding.^[6]

Some pharmacological treatments (e.g., olanzapine, mirtazapine, cyproheptadine) are being explored as adjunct therapies for ARFID to reduce anxiety related to food and stimulate appetite. However, studies on their effectiveness and long-term safety are still in the early stages, and more evidence is needed for evaluation.^[1][6][10]

There aren’t specific supplements recommended for ARFID because nutritional deficiencies vary depending on the specific foods that are avoided and/or restricted. Clinicians typically use tests to assess the individual ‘s nutritional status and in some cases may prescribe specific nutritional formulas, oral supplements (e.g., multivitamins), or tube feeding to compensate for the lack of nutrients. However, these measures are usually temporary and are supported by other therapeutic strategies aimed at reintroducing foods or increasing overall food intake in the long term.^[6]

It is important to note that it’s quite common for people diagnosed with ARFID to overuse supplements (e.g., multivitamins, nutritional formula) or to be dependent on supplements to compensate for the lack of nutrients in their diet. Although this is not considered a healthy behavior, introducing some nutrients is better than none at all. Clinicians, families, and caregivers are encouraged to avoid abruptly changing these habits and instead work on gradual strategies to incorporate new foods or increase food consumption over time.^[2]

ARFID is an eating disorder, and therefore diet plays a crucial role in the development and management of this mental health condition.

Changing the dietary patterns of people with ARFID often requires a gradual and slow process, and clinicians may need to prescribe alternatives to regular feeding to avoid situations of malnutrition.

One such method is tube feeding, also known as enteral feeding, which involves delivering nutrients in liquid form through a tube inserted into the gastrointestinal tract. The tube can be inserted through the nose or mouth or via a surgical procedure. The specific formulas or enteral food preparations used vary depending on the specific nutrient needs of the individual. Tube feeding is used to increase dietary volume and is always supported by other nutritional and psychological strategies aimed at gradually reintroducing foods and re-establishing regular feeding patterns.^[6][2]

The Feeling and Body Investigators (FBI) approach is a novel management strategy for ARFID that is designed for children aged 4 to 10 years old. This method appears to be particularly suitable for children who are hypersensitive to food or who associate food with negative emotions and/or negative body sensations. The FBI approach uses games and various cartoon characters to enhance children's self-awareness. It aims to teach children to not immediately reject uncomfortable body sensations (such as fast breathing or hunger) or unpleasant feelings triggered by external stimuli (such as olfactory stimuli). Instead, it encourages children to “investigate” these sensations through play, eventually helping them perceive them as interesting.^[11][2] Although this approach is a step forward in the management of ARFID, larger studies are required to prove the effectiveness of this method.

Another method that is already in use for eating disorders and is being explored for ARFID is called food chaining. This method aims to introduce new foods into the diets of individuals with ARFID by associating the characteristics of foods that they consider safe to eat with those of other foods that should be introduced or that the individual wants to be able to eat. Food chaining is a gradual process, and foods are introduced one at a time or a few at a time.^[2] Future research should focus on examining the effectiveness of this method specifically for ARFID patients.

The exact cause of ARFID is still unknown. ARFID has been included in the DSM only since 2013, and research on the neurobiology of this disorder is currently limited. It is understood that ARFID can be triggered by a sensitivity to the taste, texture, or smell of food, by negative associations with certain food-related body sensations, or by a lack of interest in food. However the underlying causes of these triggers are not clearly understood, and it is likely that a combination of psychological, environmental, and biological factors contribute to the development of ARFID.

Hypotheses have been proposed based on existing studies of conditions that share similarities with ARFID. Sensory hypersensitivity may contribute to the rejection of food based on taste, smell, or texture, which has been observed both in adults and children identified as “picky eaters”. A decreased activation of the brain’s appetite-regulating centers may be associated with a lack of interest in food. On the other hand, the rejection of food due to fear of adverse events, such as choking or vomiting, may be related to hyperactivation of specific areas of the brain involved in fear responses, such as the amygdala, ventrolateral prefrontal cortex, and anterior cingulate.^[6]

Genetics may also play a role in the development of ARFID. One study conducted in Swedish children between the ages of 6 and 12 indicated a heritability rate of up to 79% for ARFID. However, this study has several limitations, and the methodologies used to collect data and diagnose ARFID were not robust, so these results should be interpreted cautiously.^[12]