Assessment and Treatment of Avoidant/Restrictive Food Intake Disorder
Avoidant/restrictive food intake disorder (ARFID) is the newest eating disorder diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) (American Psychiatric Association, 2013). ARFID replaces the diagnosis of feeding disorder of infancy and childhood, and captures a broad spectrum of restrictive eating behaviors, not motivated by weight or shape, that are present across the life span. These restrictive eating behaviors may be characterized as “picky eating” or “selective eating,” or as food phobias (e.g., fear of vomiting, choking, or illness), or attributed to general poor appetite or lack of interest in eating. Many of these restrictive eating behaviors, particularly those with selective eating, have long been recognized and treated within the medical community under the heading of feeding disorders (Bryant-Waugh, Markham, Kreipe, & Walsh, 2010). However, chart reviews indicate that these individuals also make up a substantial portion of those presenting for treatment within traditional eating disorder settings. Anywhere from 8.4 percent to 22.5 percent of individuals presenting to treatment in tertiary or day treatment settings meet the diagnostic criteria for ARFID (Cooney, Lieberman, Guimond, & Katzman, 2018; Nicely, Lane-Loney, Masciulli, Hollenbeak, & Ornstein, 2014).
The eating disorder field has a long way to go in understanding this diagnosis and how it is different from more “traditional” eating disorders like anorexia nervosa and bulimia nervosa. Future research will clarify our understanding of the etiology of the restrictive eating patterns in ARFID and indicate what types of treatments may be efficacious. One treatment that is currently under study is cognitive behavioral therapy (CBT) for ARFID (Thomas, Wons, & Eddy, 2018). Results of this study have not yet been published, though—and clinicians are in need of information on how to approach this complicated eating disorder now. The fields of feeding disorders, anxiety disorders, and eating disorders can offer some helpful insights and initial treatment recommendations for ARFID.
Perhaps the most important first step in the treatment of ARFID is obtaining a comprehensive assessment of the restrictive eating behaviors, including their current nature, associated symptoms, and functions, as well as a detailed psychosocial and medical history. Of note, the restrictive eating that characterizes ARFID must be associated with at least one of the following impairments: weight loss or failure to grow (either in height or weight), nutritional deficiency, dependence on supplemental feeding (either oral or enteral), or psychosocial impairment. Thus, collaboration with a medical provider and dietitian when conducting the assessment is crucial to determining any negative effects on growth and to detecting any nutritional deficiencies. Medical comorbidities are common in ARFID, and referrals to other specialties may be indicated to rule out (or account for) the presence of other complex medical or feeding issues. Other specialties to consider may be speech and language pathology for dysphagia, occupational therapy for sensory processing disorder, and gastroenterology for the presence of functional or other gastrointestinal disorders. If any of these conditions are present, it will be crucial to incorporate complementary treatments to target these problems throughout the course of ARFID treatment.
Finally, prior to formulating a treatment plan, the clinician must have an understanding of the function or functions of the restrictive eating behavior. The field has recognized that ARFID is a heterogeneous disorder with a wide variety of presenting symptoms and complaints. The DSM-5 describes three common functions of restrictive/avoidant eating, including restriction owing to sensory sensitivities, restriction owing to fear that an aversive consequence will follow eating, and restriction owing to lack of appetite or interest in food. These descriptions have led some clinicians and researchers to adopt the stance that these functions represent distinct and meaningful “subtypes” of ARFID. However, while a recent study found that the occurrence of these subtypes could be detected with good reliability, a significant portion of patients endorsed symptoms of more than one subtype (Norris et al., 2018). Thus, others in the field have speculated that these different patterns of restrictive eating may rather represent behavioral phenotypes with distinct underlying etiologies that are not mutually exclusive (Figure 1) (Thomas et al., 2017). As such, it is important to recognize that a patient with ARFID may not fit cleanly into one “subtype” of ARFID, but rather may endorse multiple reasons for restrictive eating. It is important to recognize the presence of these distinct, yet often correlated behavioral phenotypes, as they likely indicate that different treatment approaches may be needed for different restrictive functions.
Selective Eating. Selective eating is characterized by food avoidance based on taste or textural sensitivity. Individuals may have very specific food preferences related to taste (e.g., salty or sweet), smell (e.g., weak or odorless), texture (e.g., smooth or crunchy), color (e.g., white), temperature (e.g., hot), or brand (e.g., Wendy’s chicken nuggets). Some research also indicates that these individuals are more likely to be sensitive to disgust than individuals who are not selective or picky eaters, meaning that they are more likely to find non-preferred tastes to be highly aversive (Kauer, Pelchat, Rozin, & Zickgraf, 2015). Selective preferences may be present early on in life and are influenced by genetic or biological factors, exposure to/availability of food within the family environment, social modeling of food intake, and individual temperament. It is particularly important to assess for the presence of nutritional deficiencies within this group. Selective eaters are also at risk of being underweight and for psychosocial impairment, including the presence of other psychological disorders (Zucker et al., 2015).
In addition to expanding their food repertoire to correct nutritional deficiencies, treatment for patients in this group may also need to target weight restoration and dependence on oral supplements. Clinicians may need to strike a balance between encouraging increased intake of solid foods within the patient’s preferences and encouraging exploration of new foods. Early in treatment, this balance may lean more heavily toward increasing a patient’s intake of preferred solid foods to encourage weight gain and decrease intake of oral supplements. Later stages of treatment may shift toward encouraging dietary expansion. Work in the field of feeding disorders has generally used graduated exposure as the preferred approach to adding new foods (Sharp, Jaquess, Morton, & Herzinger, 2010). This approach involves the introduction of new foods in small amounts and of varying textures and gradually increasing demand with increased acceptance. Depending on the age of the patient, this approach may also be combined with cognitive behavioral techniques to reduce anxiety and challenge negative beliefs related to trying new foods. The extent of dietary expansion in the treatment of selective eating should keep in mind patient goals related to psychosocial functioning. Clinicians should consider patient preferences and encourage the addition of new foods that allow patients to be more social or flexible in their eating style.
Fear of Aversive Consequences. Fear of aversive consequences is characterized by specific beliefs about negative outcomes that may occur after eating. These individuals avoid food because of worries that they may vomit, choke, be unable to swallow, have an allergic reaction, or become ill (e.g., owing to the presence of contaminants in the food) after eating. Others may restrict their eating because of general fears of abdominal pain or discomfort. The onset of food avoidance that’s due to fear of aversive consequences tends to follow a more acute course. There may have been a traumatic incident or a gradual worsening of the fear over the course of months. To target this presentation, it may be helpful to draw from interventions in the field of anxiety disorders that involve cognitive behavioral and exposure-based techniques. Exposures should be designed to confront both the specific fears and feared foods. For example, fears of vomiting may require exposures to specific foods associated with vomiting, as well as to vomit and vomiting itself (e.g., fake vomit, vomiting videos, gagging over toilets). When targeting fears of aversive consequences, accommodations may need to be made to the patient’s diet at the outset of treatment to encourage greater intake for weight restoration. There may also be a greater dependence on oral supplements at earlier stages of treatment. Later stages of treatment should incorporate more variety in the diet, including feared foods, and focus on decreasing dependence on oral supplements.
Poor Appetite/Lack of Interest. Poor appetite or lack of interest in food is characterized by generalized food restriction. These individuals typically are rarely hungry, get satiated early on in the meal, can go for hours without eating, and may have frequent abdominal or other somatic complaints. Some clinicians and researchers have characterized these patients in the past under the heading of food avoidance emotional disorder (Higgs, Goodyer, & Birch, 1989), a syndrome in which lack of appetite or frequent somatic complaints are related to secondary depression or anxiety. Interventions used for anorexia nervosa, particularly family-based treatment (FBT) (Lock & Le Grange, 2015) in children and teens, may be helpful for targeting poor appetite or lack of interest in food. FBT places the responsibility of feeding into the hands of parents and empowers them to override under-stimulated appetites and ensure that their children eat enough food to gain weight and grow. In adults, some aspects of enhanced CBT for eating disorders (Fairburn, 2008) may be useful to target poor appetite, including psychoeducation on restriction/undereating, food and weight monitoring, and problem solving. Complementary treatment of existing anxiety or depression may also be necessary depending on the presentation.
General Treatment Strategies. Across all three behavioral phenotypes, some general treatment strategies may be helpful. First, clinicians should ensure that the most medically dire consequences of ARFID—namely low body weight and nutritional deficiencies—are addressed first in treatment. Some interventions, such as exposure, may need to be put on hold until weight gain is established. Second, clinicians need to take into account the developmental stage of the patient. It is essential that for younger patients and teens, families be incorporated into treatment to ensure nutritional needs are met. Additional parent management training may be helpful in teaching parents how to better manage behavioral challenges around mealtimes. Patients with physical and/or developmental disabilities or feeding tube dependence may be most appropriate for treatment within traditional feeding disorder clinics, which are capable of managing more medically complex patients. Third, clinicians should strongly consider creating structure around meal and snack times and using contingency management procedures to encourage greater food intake—both of preferred and non-preferred/feared foods.
In conclusion, ARFID is a complex and heterogeneous eating disorder that requires comprehensive assessment and understanding of restrictive eating functions for appropriate treatment. Clinicians should keep in mind that the major behavioral phenotypes characteristic of ARFID may co-occur within the same patient. While future research is needed to develop and evaluate effective treatments for ARFID, established treatments from the fields of feeding disorders, anxiety disorders, and eating disorders offer helpful directions.