Alex Howard Group
March 2, 2023

Eating Disorder Awareness Week 2023: Understanding ARFID and Orthorexia in the context of fatigue-related conditions

This Eating Disorder Awareness week, we wanted to share some information on two lesser known eating disorders, A.R.F.I.D and Orthorexia, which we see commonly co-occurring in clients at The Optimum Health Clinic. In this article, Claire Sehinson, Head of Research & Protocol Development at The Optimum Health Clinic, explains the characteristics of these eating disorders and how they can present in clients with fatigue-related conditions.It is estimated that between 1.25 and 3.4 million people in the UK are affected by an eating disorder and around 25% are male.  Eating disorders do not discriminate, they affect all genders, orientations, ethnic groups and social/educational statuses. However certain groups may be more vulnerable, for example LGBT+ young people were found to be 3 times more likely to have an eating disorder (2)Having a diagnosed mental health condition dramatically increases the likelihood of having an eating disorder. E.g. OCD and eating disorders are thought to have a 41% co-occurrence rate (1). Eating disorders (EDs) are also likely to be underrepresented in ethnically diverse groups.One study found black teenagers 50% more likely to suffer from bulimia than white teenagers, whilst another study determined that black people are less likely to receive a diagnosis of anorexia than white people, or have a delayed diagnosis meaning they will have experienced the condition for longer before accessing support and medical care(7). This is partly due to unawareness and insufficient training of how EDs might present in clinic in diverse ethnic groups, and also outdated diagnostic criteria which lead to bias and gaps in the research (6). Two lesser-known eating disorders that commonly co-occur in our clients are ARFID and Orthorexia. These are both slowly gaining recognition in both general practice and the public awareness.Avoidant/Restrictive Food Intake Disorder or “ARFID” is a condition whereby the person may be avoiding or restricting foods or entire food groups due to:

  • An unpleasant sensory-based experience to characteristics in that food, such as textures, tastes or smells.
  • A fear-based response to specific foods that might be related to distressing or traumatic prior experiences (such as abdominal pain, vomiting or choking).
  • Some people may have a low appetite or disinterest in food that is secondary to another condition including Autism, ADHD, OCD or chronic pain disorders (i.e. Fibromyalgia).

In some cases ARFID might be strongly linked to internal sensory processing differences in neurodivergent individuals. For others, food restrictive/aversive behaviours can arise from trauma or PTSD, where eating disorders can be used as a coping strategy or way of control.Orthorexia is another more recently defined disorder. This term was coined in 1997, but is still not formally recognised by the DSM (Diagnostic and Statistical Manual of Mental Disorders).  Orthorexia is an unhealthy fixation with healthy eating or ‘clean’ and ‘pure’ ingredients that can end up being detrimental to the person’s wellbeing.  Eating a healthy diet and avoiding toxicants in the food chain is a common goal with nutritional therapy in fatigue recovery, however in people with orthorexia the obsession goes beyond what a Nutritional Therapist’s expectations would be or what is even realistically achievable. The person can experience feelings of extreme guilt, anxiety, stress or failure if they consume something that isn’t safe or pure.  This can lead to a very restrictive diet that lacks joy, social interaction and adds to the stress load rather than alleviating it. The distress from the compulsive checking or researching diets, ingredients, supplements or the avoidance of entire food groups can ironically leave the person vulnerable to nutritional deficiencies, gut or blood sugar dysregulation and more heightened sensitivities to foods. What causes or contributes to EDs?...Eating disorders are biopsychosocial disorders: meaning that psychological, social and biological factors all contribute to the development and also the healing of these conditions.

As an integrated nutritional therapy and psychology practice, at The Optimum Health Clinic we have to be mindful of the impact of all three areas. Due to the interwoven sensory processing differences, mental health aspects and physiological imbalances, recovery will depend on establishing safety and addressing all areas of this model.

Biological and Nutritional Factors:Gut heath and interoception: can significantly impact feeding preferences and feeding behaviours. For some clients, their symptoms may be driven by sensory sensitivities or interoceptive pain. Interoception is our internal sensory experience such as feeling hungry, nauseous or “butterflies”. Pain is also an interoceptive experience and can indicate a lack of safety in the person’s felt sense. This can be commonly overlooked when working with clients with chronic and unresponsive digestive discomfort.  We have certainly seen cases where food sensitivities, inflammation or gastrointestinal imbalances cannot explain the pattern and level of discomfort the person is experiencing. However, when we examine the factors which correlate to their symptoms, we find that emotions, memories, stressful events or beliefs about what is “good” or “bad” about that food, are all common themes.  

Microbiome and neurotransmitters: the gut-brain axis is the two-way communication between our brain and the gut. It is well known that majority of our neurotransmitters (i.e. serotonin, dopamine, GABA and noradrenaline) are made and held in the gut(3). Our gut-microbiota plays an influential role in human behaviour, mood and eating behaviours through producing and regulating both neurotransmitters and hormones(5).

When too much of a good thing is a bad thing…Interestingly, some commensal gut bacteria such as Clostridia spp. can become overgrown following prolific antibiotic use. Clostridia species can generate a toxic metabolite in our gut called HPHPA which blocks the enzyme that converts dopamine to noradrenaline. The research suggests that excess dopamine levels can drive conditions such as repetitive or addictive behaviours, agitation/anxiety and OCD and all of these factors can be prevalent in the types of disordered eating behaviours we see in clinic(4).So naturally, the gut is a great starting point of work. Our practitioners use functional testing to assess for functional imbalances, such as those listed above, and then work to address these with targeted and individualised protocols.

Nutrient deficiencies and Pyroluria: Another condition we screen for where disordered eating is identified is Pyroluria. Pyroluria is a metabolic disorder that can be genetic or acquired and is believed to affect up to 10% of the population. Higher incidences are seen in some conditions including schizophrenia, alcoholism and the autistic spectrum. Some hallmark traits include obsessive thoughts, poor stress tolerance and high anxiety, which can all underpin food obsessions such as orthorexia in our clinical experience. In cases of pyroluria, ’kryptopyrolles’ which are normally produced in small amounts as a by-product of haemoglobin production become abnormally elevated. At high levels, kryptopyrolles excessively bind to zinc and vitamin B6 which renders these nutrients biologically inactive and causes them to be excreted in the urine. This may cause a zinc and B6 insufficiency and the loss of these two nutrients has huge implications for mental health, not to mention physiological ramifications such as poor immunity, poor gut health and fatigue. Our practitioners will routinely monitor both urinary kryptopyrolle levels and mineral status, and guide clients towards the safe repletion of these depleted vitamins, whilst working to uncover and correct the deeper causal factors.

Psychological factors and a trauma informed practice:ARFID and Othorexia are both characterized by a primary hypersensitivity to sensory input and fear-anxiety responses to food. If this occurs every time someone has to eat a meal, the prolonged stress exposure over time modifies the HPA axis (our stress response made up of a complex hormonal feedback system between the brain and our adrenal glands) and alters the threshold so that it doesn’t switch off as easily and becomes hyper-vigilent and reactive to minor or non-existent threats. Consequently, food and mealtimes may become a traumatic experience and this repeated trauma may alter brain chemistry to become more prone to anxiety and depression. We refer to this as the Maladaptive Stress Response within our clinic.Unpicking this cycle requires experienced trauma-informed practice and therapeutic guidance, in order to safely support the individual.  

Establishing autonomy, safety and trust in one’s own body is a pillar of integrative care in our clinic. The client is supported with practical tools to down-regulate their maladaptive stress response and is helped to understand the unique emotional or sensory experiences around food and eating which may be fuelling their own mental and physical discomfort. The overriding clinical aim is to re-establish a healthier mind-body relationship.

Social factors:With ARFID, the sensory disorder extends beyond the person’s interoception or prior traumatic experiences to food. We recognise that eating is a multi-sensory and emotional experience, as one of my clients with ARFID explains: “I feel intense sensory overwhelm when eating out in cafes or restaurants – it’s the combination of noisy conversations, lots of different smells and visually too much going on – it can bring on pains in my gut, nausea, disassociation and a fear of vomiting in public even thinking about it!”Another client described:“people think that I’m just a picky eater because I need to eat the same breakfast cereal every day or I am counting calories because I’m afraid of gaining weight. The reality is this cereal is predictable and safe, I know it will always have the same texture, flavour and I will have the same experience eating it and this is calming and reassuring and one less thing to worry about”This helps us to appreciate why traditional nutrition strategies solely focused on expanding their breakfast options would not get to the root of the issue in this case.  

Equally, understanding that the person with ARFID may struggle with socially constructed ideals such as “we should all eat together at the dinner table” or “you need to eat everything on your plate” is an important step in identifying how we might proceed and offer more effective support. Finally, bad science and the media perpetuate unrealistic “norms” and goals about what a healthy body looks like. The unattainable ideals of purity and morality (what makes you good or bad) as it relates to food choices stems from Healthism. Healthism is a social concept coined by Robert Crawford in the 1980s, which placed the responsibility of health solely on an individual’s shoulders.

Body liberation interventions such as Health At Every Size (HAES) challenge our idea of what is “normal” and acknowledges that healthy bodies come in a diverse range of shapes and sizes influenced by genetic makeup and cultural traits. The HAES framework is not suggesting everyone is healthy at every size, rather it aims to reduce weight stigma or discrimination, especially in healthcare settings, by focusing on parameters that go beyond how much you weigh. The framework centres on self-acceptance and regaining trust in the body’s ability to regulate itself given a more mindful approach to diet and exercise which honours one’s needs and does not discount pleasure. As practitioners, we can better support those with disordered eating behaviours by: honouring the person’s sensory preferences; helping them to understand their emotional connection to eating; identifying and correcting underlying functional imbalances with the appropriate nutrition support and finally encouraging a realistic and mindful self-acceptance for their body and it’s wonderful innate capacity.


  • Kaye WH, Bulik CM, Thornton L, Barbarich N, Masters K. Comorbidity of anxiety disorders with anorexia and bulimia nervosa. Am J Psychiatry. 2004 Dec;161(12):2215-21. doi: 10.1176/appi.ajp.161.12.2215. PMID: 15569892.
  • Report
  • Mittal R, Debs LH, Patel AP, Nguyen D, Patel K, O'Connor G, Grati M, Mittal J, Yan D, Eshraghi AA, Deo SK, Daunert S, Liu XZ. Neurotransmitters: The Critical Modulators Regulating Gut-Brain Axis. J Cell Physiol. 2017 Sep;232(9):2359-2372. doi: 10.1002/jcp.25518. Epub 2017 Apr 10. PMID: 27512962; PMCID: PMC5772764.
  • Shaw W. Increased urinary excretion of a 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), an abnormal phenylalanine metabolite of Clostridia spp. in the gastrointestinal tract, in urine samples from patients with autism and schizophrenia. Nutr Neurosci. 2010 Jun;13(3):135-43.
  • Seitz J, Trinh S, Herpertz-Dahlmann B. The Microbiome and Eating Disorders. Psychiatr Clin North Am. 2019 Mar;42(1):93-103. doi: 10.1016/j.psc.2018.10.004. Epub 2018 Dec 17. PMID: 30704642.
  • Halbeisen G, Brandt G, Paslakis G. A Plea for Diversity in Eating Disorders Research. Front Psychiatry. 2022 Feb 18;13:820043. doi: 10.3389/fpsyt.2022.820043. PMID: 35250670; PMCID: PMC8894317.
  • Sala M, Reyes-Rodríguez ML, Bulik CM, Bardone-Cone A. Race, ethnicity, and eating disorder recognition by peers. Eat Disord. 2013;21(5):423-36. doi: 10.1080/10640266.2013.827540. PMID: 24044598; PMCID: PMC3779913.
  • Marmot review: Fair Society, Health Lives, 2010
  • The World Health Organization

Written by Claire Sehinson, Head of Research & Protocol Development at The Optimum Health Clinic.This is an informative article discussing eating disorder awareness. If the themes contained within are triggering or emotionally challenging, please ensure that you speak with your local G.P. to seek more advice and medical support.

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