The intersection between Avoidant/Restrictive Food Intake Disorder & Anorexia Nervosa
The intersection between Avoidant/Restrictive Food Intake Disorder (ARFID) and Anorexia Nervosa (AN) is a complex area within eating disorders. Anorexia and ARFID can coexist or be misidentified as one another, making treatment and support more challenging.
This difficulty is exacerbated by their overlapping traits, including restrictive eating patters, weight loss and the risk of nutritional deficiencies. Thus understanding their overlaps and differences is crucial for targeted interventions and support.
This is particularly important for neurodivergent individuals as both AN and ARFID are highly prevalent amongst neurodivergent individuals, particularly autistic females.
Underlying Drivers
ARFID is not driven by a desire for thinness or body image concerns. Instead, it is often related to previous food trauma, sensory processing differences (e.g., certain textures, smells, or colors of food), fear of aversive experiences (e.g., choking or vomiting), or a lack of interest in food.
AN is driven by an intense fear of weight gain, difficulties maintaining body weight and negative body image. The restriction in food intake is usually intentional, with a focus on controlling weight and shape. Important to know that for Neurodivergent people this might be different, the fear of weight gain may not be associated with body image. It may be more a sensory aversions or sensory need.
People of all sizes, ages and genders can develop ARFID and AN.
Key Similarities
Weight loss and nutritional deficiencies: Both ARFID and AN involve restrictive eating behaviors that may result in significant weight loss or nutritional deficiency, but this is not always true. Weight loss is especially variable, as individuals with ARFID or AN can be in larger bodies. Additionally, some people with ARFID may thrive on their preferred safe foods. If weight loss or nutritional deficiencies do occur, this can have physical consequences, such as malnutrition, growth concerns in children or electrolyte imbalances.
Limited range of safe foods: Both AN and ARFID can involve a limited range of safe foods, though the reasons may differ. In ARFID, individuals may have a restricted diet due to sensory differences, anxiety/fear of foods, or a lack of interest in eating.
In AN, the limited range of foods is often due to fears around weight gain and strict rules about what is considered acceptable to eat. Despite these differences, both can lead to a narrow selection of foods that feel safe to consume.
Interoceptive differences: People with AN and/or ARFID can have interoceptive awareness differences. This affects perception of appetite, hunger and fullness in different & unique ways.
Gastrointestinal issues: People with AN and/or ARFID may experience gastrointestinal issues due to food restriction & limited food intake. This can lead to slowed digestion, constipation, and bloating, as the gut may struggle to process food after periods of restriction. Additionally, the lack of variety can result in deficiencies of key nutrients, like fiber, which are crucial for maintaining healthy digestion. Over time, these digestive issues can become more pronounced, creating a challenging cycle that can make eating even more inaccessible.
Preference for eating alone: It can be difficult eating with others or in social settings for both ARFID and AN, though for slightly different reasons: in ARFID, it’s often due to anxiety about the food itself, lack of safety with others, perceived judgement, or sensory overwhelm.
With AN, it’s often related to fears of perceived judgment or criticism, fear people will not believe you are actually sick because you’re eating, or losing control.
Anxiety or difficulty eating new foods: For individuals with ARFID, the thought of trying new foods may provoke a lot of anxiety or fear due to a lack of safety, familiarity or comfort with that food.
In AN, the anxiety around new foods is often related to fears about losing control, gaining weight, or consuming foods that don’t fit into strict dietary rules. In both cases, the fear or discomfort with unfamiliar foods can make it challenging to expand the variety of foods in their diet.
Fear/anxiety associated with eating: In ARFID, the anxiety is often related to previous food trauma or the sensory experience of food. This makes certain foods or eating experiences feel overwhelming and/or unsafe.
In AN, the fear is typically centered around concerns about body image and weight gain. Eating can provoke anxiety due to worries about consuming too many calories, losing control over dietary restrictions, or the potential for weight changes.
Despite these different underlying fears, both ARFID and AN involve significant distress around eating.
Written by Margo White, your Melbourne-based neurodiversity affirming clinical nutritionist and Neurodivergent advocate.
This article is intended as general advice only and does not replace medical advice. It is recommended that you seek personalised advice specific to your individual needs.
References:
https://neurodivergentinsights.com/misdiagnosis-monday/anorexia-and-arfid#differences
https://nedc.com.au/eating-disorders/types/arfid
