Overview
Avoidant/Restrictive Food Intake Disorder is an eating disorder whose symptoms lead to a nutritional deficiency as well as considerable weight loss among individuals diagnosed with it. Individuals with the disorder typically have aversive reactions to food, which may be due to sensory sensitivities to food, or due to the fear of potential negative consequences of food intake. The consequences of the disorder among children or adolescents commonly comprise of malnutrition and the inability to reach developmental milestones associated with growth. Among adults, the disorder can have a considerable effect on social functionality.
While there is a paucity in epidemiological data for the disorder, a male preponderance has been determined thus far. The disorder may be diagnosed at any age, but the onset is most commonly observed in childhood. The aetiology of the disorder involves genetic, environmental, temperamental, as well as sociocultural factors. Psychiatric comorbidities may be involved.
Treatment modalities for the disorder consist of psychotherapeutic and pharmacological approaches, though multimodal management is recommended.
Signs and Symptoms
The signs and symptoms of Avoidant/Restrictive Food Intake Disorder may include:
- Avoiding or restricting consumption of food
- Significant weight loss
- Significant nutritional deficiencies
- Lack of interest in food
- Among children and adolescents, failure to meet developmental growth milestones
- Being sensitive to the smell, appearance, or taste of food
- Intolerance towards food
- Being worried that consumption of food will lead to aversive consequences such as vomiting
- Anxiety involved with the prospect of consuming food
Risk Factors
Avoidant/Restrictive Food Intake Disorder presents with an equal distribution among males and females, but is considered to have a male predominance when comorbid Autism Spectrum Disorder is present. There is no age restriction for the diagnosis of the disorder, though it is considered to commonly develop as aversion or food-related lack of interest that extends into adolescence and adulthood.
Genetic risks are often involved in the manifestation of eating disorders, and thus a familial pattern of eating disorders may be a predisposing factor in the occurrence of Avoidant/Restrictive Food Intake Disorder. A history of medical problems associated with food intake, including gastrointestinal issues, have also been identified in relation to the disorder. The presence of neurodevelopmental, obsessive-compulsive, or anxiety disorders often lead to sensory reactions to food that may lead to restrictive eating habits.
Studies have illustrated the aetiology of Avoidant/Restrictive Food Intake Disorder with the presence of selective eating patterns observed since an early age, as well as temperamental issues such as irritability or difficulty consoling during feeding in infancy. Restrictive food consumption is largely attributed to a fear of food contamination, as well as adverse consequences of consuming food such as choking, swallowing, or concerns with the smell, taste, appearance, or texture of food. This may result from sociocultural influences that affect the way food is viewed by the individual. Negative parent-child experiences revolving around food, such as the inappropriate presentation of food at a young age may also contribute to this.
Environmental factors have also been identified, and include parental psychopathology, namely anxiety disorders among parents or caregivers. Child abuse or neglect can also have an impact on the development of Avoidant/Restrictive Food Intake Disorder. Past traumatic experiences associated with the consumption of food may precipitate the fear of negative consequences associated with restrictive or avoidant behavior towards food.
Diagnosis
A complete and thorough clinical assessment is imperative in the diagnosis of Avoidant/Restrictive Food Intake Disorder. A detailed history of the individual is taken, keeping in mind developmental, feeding, nutritional, and psychosocial aspects. The timeframe of the initial presentation of symptoms must be determined. The impact of disturbances in eating patterns must be assessed. Family history is also taken.
A complete physical check-up is typically part of the assessment, including measurements of height, weight, and determination of BMI (Body Mass Index). Pulse, blood pressure, and oral temperature may also be taken. Laboratory assessments are carried out in order to check for nutritional deficiencies, if any.
The Pica, ARFID and Rumination Disorder Interview (PARDI) and the Eating Disorder Examination – ARFID module (EDE-ARFID) are tools used to look for symptoms of Avoidant/Restrictive Food Intake Disorder.
The DSM-5 includes the following criteria for the diagnosis of Avoidant/Restrictive Food Intake Disorder:
- An eating or feeding disturbance (e.g., apparent lack of interest in eating or food; avoidance based on the sensory characteristics of food; concern about aversive consequences of eating) as manifested by persistent failure to meet appropriate nutritional and/or energy needs associated with one (or more) of the following:
- Significant weight loss (or failure to achieve expected weight gain or faltering growth in children).
- Significant nutritional deficiency.
- Dependence on enteral feeding or oral nutritional supplements.
- Marked interference with psychosocial functioning.
- The disturbance is not better explained by lack of available food or by an associated culturally sanctioned practice.
- The eating disturbance does not occur exclusively during the course of anorexia nervosa or bulimia nervosa, and there is no evidence of a disturbance in the way in which oneโs body weight or shape is experienced.
- The eating disturbance is not attributable to a concurrent medical condition or not better explained by another mental disorder. When the eating disturbance occurs in the context of another condition or disorder, the severity of the eating disturbance exceeds that routinely associated with the condition or disorder and warrants additional clinical attention.
Treatment
The treatment approaches for Avoidant/Restrictive Food Intake Disorder depend on the level of severity of the disorder as well as the level of instability of the patient. In unstable patients, hospitalization may be required, and feeding through nasogastric tubes may be implemented. The use of multimodal interventions is proposed.
Psychotherapeutic treatment for Avoidant/Restrictive Food Intake Disorder often makes use of Cognitive Behavioral Therapy. Approaches focus on anxiety associated with food consumption, and do not make use of the modalities focusing on weight as used in other eating disorders. Factors causing food avoidance are also targeted, usually through exposure-based interventions. Sensitivity to being disgusted by foods, negative thoughts about foods and fear, and the thoughts pertaining to negative consequences of food consumption are explored. Family based interventions also give importance to the roles of caregivers, working on reducing guilt felt by family members and encouraging a supportive environment.
Pharmacological treatment modalities consist of the proposed use of antipsychotic, antidepressant, and anxiolytic drugs, namely olanzapine, mirtazapine, and buspirone. However, varying results of the use of the medication has been observed, and there is a need for further research in order to generalize their efficacy.
Differential Diagnosis
1. Major depressive disorder: Loss of appetite and loss in weight are common with major depressive disorder. Although the restrictions to intake are general and not particular in nature.
2. OCD: Individuals with obsessive-compulsive disorder may show signs of avoidance or restriction of intake because of their preoccupations with food or ritualized eating behavior.
3. Autism spectrum disorder: People with autism spectrum disorder have fixed food habits and are highly sensitive to other foods. However, that does not cause any impairment as seen in avoidant/restrictive food intake disorder. Differential diagnosis between avoidant/restrictive food intake disorder and anorexia nervosa may be difficult, especially in late childhood and early adolescence, because these disorders may share a number of common symptoms. In some individuals, avoidant/restrictive food intake disorder might precede the onset of anorexia nervosa.
4. Schizophrenia spectrum disorders: Individuals with schizophrenia, delusional disorder, or other psychotic disorders may practice odd eating behaviors, avoidance of specific foods because of delusional beliefs, or other manifestations of avoidant or restrictive intake. In some cases, delusional beliefs are a cause for negative consequences of ingesting certain foods.
5. Anorexia nervosa: Individuals with anorexia nervosa display a fear of gaining weight or of becoming fat,ย as well as specific disturbances in relation to perception and experience of their own body weight and shape. These features are not present in avoidant/restrictive food intake disorder.ย
6. Reactive attachment disorder: Changes in the caregiver and child’s relationship affects the childโs food intake but the other criteria of the disorder need to be met along with the feeding disturbances.
7. Other medical conditions: Conditions with symptoms of nausea, vomiting, abdominal pain, diarrhea, loss of appetite may lead to restrictions regarding food intake. Postsurgical patients or patients undergoing chemotherapy are also known to refuse food intake.
Comorbidity
Commonly comorbid conditions to avoidant/restrictive food intake disorder are anxiety disorders, OCD, neurodevelopmental disorders like ADHD and autism.
Specialist
As a disorder commonly observed in childhood, Avoidant/Restrictive Food Intake Disorder is likely to be diagnosed by a paediatric healthcare provider, but may also be assessed by a primary healthcare provider in adult populations. The treatment may involve the expertise of various individuals, including primary healthcare providers and practitioners trained in appropriate therapy with expertise in eating disorders.
