Extreme Picky Eating

It entered DSM-5 in 2013, extending and replacing the older diagnosis of feeding disorder of infancy or early childhood, and reached ICD-11 in 2022. It occurs across the entire weight spectrum, though it is most often associated with low weight.

How people arrive at ARFID by different routes

Sensory difficulty is the commonest. Fruit or vegetables experienced as intensely bitter, or a smell, texture, appearance, colour or temperature that is unbearable. The sensitivity can be specific enough that a person refuses a particular brand. It usually starts in early childhood and lasts.

Fear of consequences is the second: avoiding food or restricting the amount out of fear of choking, vomiting or stomach ache, often after a frightening experience with food. The material describes the trap precisely. Avoiding the food relieves the fear in the short term, and over time the avoidance makes the anxiety worse by removing every chance of a corrective experience, while the set of avoided foods widens. In extreme cases it expands to take in all solid food.

Lack of appetite or interest is the third, and the phrase used for it is unusually clear: patients may perceive eating as a chore. Low body weight or failure to thrive are common in that group and the disinterest is long-lasting.

Multiple reasons apply in many cases.

What ARFID is not

The exclusions are as informative as the criteria. What falls outside the diagnosis is:

• restricting food because it is unavailable, as in food insecurity
• dietary restriction from cultural practice such as religious fasting
• dieting
• restricting out of concern for body weight or shape, which is anorexia nervosa or bulimia nervosa

And it is not ordinary picky eating. Toddlers and small children are commonly picky and it usually resolves by itself. ARFID is the version severe enough to produce nutritional deficiency, poor weight gain or significant weight loss, and real interference with psychosocial functioning.

Where ARFID and anorexia become hard to separate

The distinction from anorexia nervosa is not always clean, and the source gives two routes across it in opposite directions.

Somebody may begin restricting because of body concerns, lose those concerns over time, and continue undereating through nausea and anxiety around food, which is ARFID's low-appetite presentation. Or an adolescent may begin with severe sensory processing difficulty and later develop body image concerns.

The Minnesota Starvation Experiment of the 1940s is invoked to explain why. Starvation itself, whatever caused it, produces a range of eating disorder behaviours, which means a long enough period of restriction starts generating symptoms that no longer identify what began it.

Which diagnoses ARFID most often arrives with

More than half of people with ARFID have another neurodevelopmental, psychiatric or somatic diagnosis, on a 2022 Harvard study, with anxiety, depression, sleep disorders and learning difficulties particularly common.

Anxiety disorders are the commonest comorbidity, at thirty-six to seventy-two per cent. A 2023 review found considerable overlap with autism, with between eight and fifty-five per cent of children diagnosed with ARFID being autistic, and sensory-based avoidance the most common shared symptom.

Attention deficit hyperactivity disorder contributes through a route that has nothing to do with fear: inattention and distraction leading to missed meals, compounded by stimulant medication suppressing appetite, which makes treating the eating disorder harder.

Obsessive-compulsive disorder co-occurs, with overlap in food-related obsessions and eating rituals. Paediatric acute-onset neuropsychiatric syndrome may be a subset of ARFID, according to the PANS and PANDAS Physicians Network. Major depressive disorder is more common than in the general population, and the material says plainly that more clinical research is needed there.

What the ARFID screen measures

The Nine Item Avoidant and Restrictive Food Intake Disorder Screen assesses three things across nine items on a six-point scale: picky eating, appetite, and fear.

As of June 2024 the diagnostic tools and treatment protocols were still being developed, and a review in the Journal of Eating Disorders is direct about why: limited understanding of avoidant and restrictive eating and of its neurobiology makes effective treatment difficult.

That review also makes an argument worth recording. It holds that patients should not be segmented into separate sub-profiles, sensory patients being the example given, and that treatment should be personalised instead. Given that most cases involve more than one route in, sorting people by their apparent route is a filing error rather than a clinical one.

What ARFID treatment can and cannot do

Nutritional intervention comes first, working with clinicians including a dietitian on weight restoration and nutritional deficits, with supplements and, in severe cases, nasogastric or gastrostomy tube feeding.

On medication the position is unambiguous. The United States Food and Drug Administration has approved no psychotropic medication for ARFID and the empirical evidence is extremely limited. Small case studies point at three possibilities: olanzapine, mirtazapine and buspirone.

Behavioural work has promising results from cognitive behavioural therapy adapted for ARFID and from family-based therapy, which was developed for anorexia nervosa and is used here for children and teenagers. Responsive feeding therapy, built around a support person establishing mealtime routines, is common in Australia. The evidence for all of it is described as limited.