Eating disorders: identification, treatment and support

For many patients, eating disorders manifest as severe and chronic mental health conditions. They are considered to have the highest mortality rate among all psychiatric disorders, with a standardised mortality rate of 5.9 for anorexia nervosa in comparison to 2.2 for other mental disorders​[1,2]​.

Eating disorders are characterised by disturbed food intake or eating behaviour that significantly affects physical health or psychosocial functioning and those who suffer from them display prominent body weight and shape concerns​[3,4]​. This combination of significant dissatisfaction with body shape and overvalued ideas about shape and weight is known as the core psychopathology of an eating disorder​[5]​. Perhaps more importantly, however, those with an eating disorder often find that it becomes their primary method for coping with past traumas, difficult situations or painful feelings that occur on a day-to-day basis. It is likely that a complex interaction between psychology, biology, societal pressures and values leads to the development of an eating disorder, making recovery difficult​[6,7]​.

There is uncertainty around how many people in the UK have a diagnosable eating disorder but the number has been estimated at between 1.25 and 1.37 million, with around 25% of those identifying as male​[8]​. Annual incidence rates are estimated to be 63 per 100,000 females of all ages and 7.1 per 100,000 in males. The highest incidence rates are thought to be in female adolescents aged 15–19 years​[9]​.

Some evidence suggests that the incidence of eating disorders is increasing overall​[9]​. Hospital admissions for eating disorders in the UK increased by 84% between 2015/2016 and 2020/2021, suggestive of a growing problem in the UK​[10]​. The reasons for this rise are not well understood; it has been suggested that it could be a result of increased awareness and better detection, or a consequence of increasing levels of psychological distress across society more widely​[9,11]​.

Currently eating disorders are categorised into the following types: 

• Anorexia nervosa; 
• Bulimia nervosa; 
• Binge eating disorder; 
• Avoidant-restrictive food intake disorder (ARFID);
• Pica (where a person compulsively swallows non-food items);
• Rumination regurgitation disorder; 
• Other specified feeding or eating disorders (OSFED)​[4]​.

While ARFID, pica and rumination regurgitation disorder are recognised as distinct eating disorders, they do not share the same core psychopathology as the other categories of eating disorders, require significantly different treatment interventions and are not consistently seen in specialist eating disorder services, placing them outside the scope of this article. In the case of OSFED, current guidance suggests care and treatment in line with the diagnosis it most closely resembles​[12]​.  

Causes and risk factors

There are many theories about the causes of eating disorders​[13]​. For example, the reduction of calorific intake and semi-starvation mirrors eating disorder symptomology and it has been argued that the neuroendocrine changes in starvation results in the brain mechanisms of reward being activated when food intake is reduced​[14,15]​. What is not clear from theories such as this is what drives a person to engage in the process initially and how, in the case of anorexia nervosa, the person seemingly overrides the body’s weight control system​[16]​.

Twin studies give rise to evidence for a genetic component to the development of eating disorders; however, precisely how genes affect development is less clear and the field of epigenetics in eating disorders, in the same way as many other areas, is in its infancy​[17–19]​. Nonetheless, while genes may give rise to an underlying vulnerability to the development of an eating disorder, it is likely that the process of developing and maintaining an eating disorder is multifaceted and complex​[20]​. It is generally agreed that there are multiple biopsychosocial factors leading to the development of an eating disorders in individuals​[21]​.

Some of these factors are likely to be intrapersonal: there is evidence to suggest that people who display obsessive-compulsive traits in childhood, anxiety or borderline traits (e.g. emotional instability, dichotomous thinking) are more likely to develop an eating disorder in later life​[18,22,23]​. Perfectionism and low self-esteem also strongly relate to the development of eating disorder symptomology​[24,25]​. Many of these factors may also be associated to early attachment styles, suggesting that early experiences — and specifically the development of an insecure attachment style — may be a risk factor for the development of an eating disorder​[26,27]​.

While intrapersonal factors, attachment and genetics appear to be factors influencing a person’s vulnerability to developing an eating disorder, there is often a specific trigger or triggers that precipitate the development of difficulties with food and eating. These could be a traumatic or stressful event, such as bullying or sexual abuse, the development of an avoidant coping style, low confidence or low self-efficacy​[28,29]​. These factors have been shown to be related to a significant focus on shape and weight​[30–32]​.

The reason for the focus on shape and weight may result from societal and cultural influences. It is well documented that many cultures place high value on certain body types, often celebrating low weight or overly thin figures as being ideal, and these cultures tend to have high rates of eating disorders​[33]​. As Western norms in relation to weight and shape have been accepted and have become the norm in other cultures, so has an increase in weight consciousness and the prevalence of eating disorders globally​[34]​.

With the advent of social media, there has been increasing concern as to the effect of this on consumers’ mental health, with regular articles in various newspapers suggesting execrable harm to users​[35,36]​. While the evidence appears somewhat more nuanced in relation to mental health generally, there is some suggestion that social media can and does have a negative effect on body image, increasing the likelihood of engaging in dieting and weight loss — behaviours that are known risk factors for the development of an eating disorder​[37–40]​.

More recently, there has been a consensus for the need for early intervention in eating disorders, with the suggestion that the earlier a person engages in treatment, the more successful intervention is likely to be​[41]​. Rates of recovery can be as high as 84%, although remission rates vary across presentations and the longer the illness duration, the less the likelihood of recovery​[20,42]​.

While people with an eating disorder make up a small percentage of those with psychiatric conditions (approximately 6.4%), it is likely that those who display signs of disordered eating in the general population, such as overestimation of body weight and engaging in restrictive eating behaviours, is greater and increasing​[43–45]​.

Identification

Identification can be challenging as patients do not always readily present to services seeking support or even engage with the idea that there is something wrong​[46,47]​. There are several possible reasons for this; in the case of anorexia nervosa this may result from the egosyntonic (aligned with personal values and self-image) nature of the disorder, a distorted body image leading to the person seeing themselves as overweight or fat and a lack of insight into their difficulties​[48]​.

In binge eating disorder and bulimia nervosa, reluctance to seek support and talk to others about symptoms may be related to feelings of shame and disgust around purging (usually self-induced vomiting) and/or binging behaviours​[49,50]​. Often, presentation may be instigated by friends and family or be prompted by another factor unrelated to the disorder entirely. They may present with a general complaint of vague physical symptoms, such as difficulties with fatigue, dizziness or constipation, rather than explicitly stating they may have an eating disorder​[51–54]​.

Signs and symptoms

Signs and symptoms vary across the spectrum of eating disorders (see Table 1​[55,56]​). People with anorexia nervosa and bulimia nervosa will often engage in dieting behaviours, such as fasting, calorie counting, avoiding meals and using exercise, as a way of attempting to manage weight, as well as using diet pills, laxatives and diuretics​[57]​. Often people with an eating disorder will weigh themselves frequently and engage in other body checking behaviours such as assessing appearance, shape or size​[57]​.

Physical symptoms, such as sleep disturbance, delayed gastric emptying, feeling cold and poor energy levels, are often present as a consequence of inadequate nutrition and being underweight​[57]​. Those who self-induce vomiting may suffer from bloating, sore throats, fluid and electrolyte disturbances and dental problems​[58]​. Eating disorders can affect menstruation regardless of body mass index (BMI) and is not restricted to those with a diagnosis of anorexia nervosa​[59]​. Libido can also be negatively affected. Physical consequences of obesity, such as type 2 diabetes mellitus and hypertension, may be present in those who struggle with binge eating disorder​[60]​.

In people who significantly restrict their eating, semi-starvation can lead to depressed mood, anxiety, difficulties in concentration and obsessive-compulsive symptoms​[57]​. People with low BMI often display significant rigidity in their thinking and impaired decision-making abilities​[61]​. Anxiety and depression is also seen in people who binge eat and there is some suggestion that binging can function as a mood management strategy in the short term, while reinforcing low mood or anxiety as a longer term consequence​[62]​.

Screening

People with an eating disorder are likely to present in a variety of settings seeking support with a range of symptoms without necessarily disclosing difficulties with eating​[63–65]​. These symptoms are often gastrointestinal, gynecological or psychological (e.g. anxiety and depression) in nature so there is a need to consider an eating disorder as a differential diagnosis and screen for this when an eating disorder is suspected, rather than expect a person to disclose their difficulties.

For pharmacists, there may be multiple opportunities to support the identification of people with an eating disorder; for example, when over-the-counter medication is being used to facilitate weight loss or compensate for binging and there are frequent or multiple purchases of laxative or diuretics. There may also be opportunities to identify eating disorders during medication reviews, multidisciplinary team meetings or ward rounds when considering the health, wellbeing and behaviour of patients.

National Institute for Health and Care Excellence (NICE) guidance suggests the use of screening tools, such as the SCOFF test, to support the identification of eating disorders in primary care settings, although the use of these tools need not be limited to these settings​[12,66]​. SCOFF is a mnemonic produced from key words within the test (see Box 1​[66]​). Identification of eating disorders should not be made based on the results of screening tools alone.

Following a positive screening or when an eating disorder is suspected owing to other reasons, a more detailed history can be taken asking for information such as further details regarding eating disorder behaviours, physical health complications and mental health difficulties; however, care should be taken with any attempt to gain further information about an individual’s presentation. It is important to balance the need for the assessment of symptoms and risk with the function of the conversation. For instance, the depth of assessment/information seeking will be different when the purpose is making a referral to specialist services compared with the aim of signposting to GP or other avenues of support (e.g. the eating disorders charity BEAT).

Any conversation regarding difficulties should be approached in a way that is sensitive and compassionate being mindful of the high levels of shame people with an eating disorder can experience. Adopting a communication style that is calm and empathetic and avoids making assumptions about the function of the eating disorder is likely to be the most helpful approach. Overly simplistic advice (e.g. ‘just eat more’ or ‘stop using laxatives’) should be avoided. 

If an eating disorder is suspected, gentle exploration of the person’s health (if visibly unwell) or behaviours (such as multiple purchases of laxative or diet aids) should be undertaken in privacy and after gaining consent. The key to any conversation is to raise the issue in a way that is non-judgmental and does not put the person under pressure. If the initial queries are met with denial, it is important to not react negatively. It may be that several conversations are necessary to develop a relationship that is trusting and safe enough to be able to discuss any concerns.  

If someone acknowledges their difficulties with food and eating in a community setting, signposting to their GP would be appropriate. It would be wise to follow up with the person if possible because people with an eating disorder often experience significant ambivalence with regards to recovery and may need further support to take the next steps in accessing appropriate treatment​[67]​. In other settings, such as inpatient wards or GP surgeries, it may be appropriate to contact a local eating disorder service for advice or to make a referral.

Service provision for the treatment of eating disorders may vary according to location, and advice should be sought from local services regarding the referral and treatment options that are available. There may be a variety of treatment options, including primary care services such as NHS Talking Therapies for Anxiety and Depression (formerly Improving Access to Psychological Therapies services), specialist eating disorder services in secondary care and offers from third sector providers. Access to these services may be based upon eating disorder type and/or severity, and services will likely require information regarding eating disorder symptoms/presentation, BMI, other co-morbid mental health difficulties and risk related to physical health and/or self-harm and suicide.  

Diagnosis and assessment

When assessment is conducted in specialist eating disorder services, a detailed history is taken to understand the symptoms, physical health and potential risk, as well as the social and psychological experiences of the person in order to make a diagnosis of an eating disorder(see Box 2). Physical health tests and examinations are often completed or ordered. Consideration is given to differential diagnoses and physical causes for the person’s symptoms are also ruled out.

Several physical examinations and investigations may be necessary for individuals with an eating disorder, especially in those with a low BMI and/or who engage in self-induced vomiting or other compensatory behaviours, such as abuse of laxative and diuretics (see Table 2​[68]​).  

Detailed information regarding assessment for people with an eating disorder can be found within NICE guidance NG69 and ‘Medical Emergencies in Eating Disorders: Guidance on Recognition and Management’​[12,69]​.  

There may be an expectation for basic physical health tests to have also been completed prior to referral, and the physical healthcare of people under eating disorder services can occur within primary care settings. This may be overseen and managed by the person’s GP, or in collaboration with specialist services, and is dependent on local commissioning.

Treatment and management

Treatment for an eating disorder is predominantly a combination of psychological therapy and nutritional advice/rehabilitation. Various modalities of therapy are available dependent on age and presentation (see Table 3 for NICE recommended modalities​[12]​). All modalities generally seek to regulate eating patterns and support the development of healthy coping strategies. In the case of anorexia nervosa, treatment also aims to support the restoration of weight, with the aim of reaching and maintaining a healthy BMI.  

Medications should not be offered as the sole treatment for an eating disorder, and there is limited evidence for efficacy in this population. The selective serotonin reuptake inhibitor fluoxetine can be used in bulimia nervosa and binge eating disorder where it can reduce binge-purge/binge cycles​[70–72]​. More recently, there is also some evidence that supports the use of topiramate (although this is often not well tolerated) in the treatment of bulimia nervosa and lisdexafetamine for binge eating disorder in order to reduce the frequency of binges, although neither medication is currently licensed for use in this way in the UK​[72]​. 

There is limited evidence to suggest that atypical antipsychotic medication can be helpful in people with severe anorexia nervosa with significant agitation, anxiety or delusional body image disturbances but they are not considered effective as a method of enhancing weight gain in this population and would be used off-licence​[73]​. Nonetheless, medication may be indicated to treat any co-morbid physical or mental health diagnosis and it is important to ensure that any underlying co-morbid difficulty, such as anxiety and depression, is treated adequately through either appropriate medication, therapy or a combination of the two.

Owing to the nature of eating disorders, there are often other management considerations, such as micro and macronutrient deficiencies. Therefore, psycho-education should be provided, and the person should be encouraged to manage this through diet. Recommendation of age-appropriate oral multivitamins could be considered until dietary intake is adequate​[12,72]​.

If there are significant macronutrient deficiencies that have led to low weight, the possibility of refeeding syndrome should be considered (see ‘Complications‘ for further information). The Royal College of Psychiatrists Medical Emergencies in Eating Disorders (MEED) guidance should be consulted and followed if necessary​[69]​. When there is a failure in low weight individuals to gain weight through increase of dietary intake, it may be appropriate to consider oral nutritional supplementation; however, this would not be first-line treatment and would be prescribed in line with oral nutritional supplementation guidance for as short a period as possible. Oral nutritional supplementation is usually only trialled following specialist dietetic assessment and on their advice​[74]​.

Differences between the management of eating disorders in adults and children and young people are usually in relation to psychological treatment modality. Certain physical risk thresholds will also be lower in children and young people owing to the potential effects of restriction of intake on growth and puberty​[75]​.

Considerations for medication risk management

When medications have been prescribed for people with an eating disorder, it is necessary for the impact of any potential malnutrition or eating disorder behaviours, such as self-induced vomiting, to be taken into account​[12]​. Eating disorder cognitions, such as the fear of weight gain, may lead to difficulties in compliance in medicines that have side effects related to this and counselling at the point of dispensing may be necessary to support compliance. When there are difficulties with compliance, alternative medications may have to be considered utilising support and guidance from pharmacists where needed.  

If medications may compromise physical heath (e.g. cardiac functioning), care should be taken to ensure that this is monitored in line with NICE guidance​[12]​. Pharmacists are able to highlight when this becomes necessary and support adherence to the monitoring process, as well as ensuring that potential adverse effects and/or interactions are considered and discussed with the patient as appropriate.

As previously discussed, medications such as stimulants, laxatives and/or diuretics may be misused by people with an eating disorder to support weight loss or prevent weight gain following binging and this should be considered during assessment of symptoms and behaviours​[76]​. Strategies for reduction and elimination of the use of such medications should be incorporated into treatment plans and there may be opportunities for pharmacists to support the development of these plans​[76]​. Pharmacists working in the community should be alert to requests for medications that may be inappropriate or excessive and be mindful of a potential opportunity for intervention and signposting to GP or local services when this is the case.

Management of comorbidities

People with an eating disorder may have various co-morbid diagnoses. These could include diabetes and other physical health problems, as well as mental health problems such as anxiety, depression or personality disorders. There are also known links between autistic spectrum condition (ASC) and difficulties with food and eating and high rates of co-morbid diagnosis especially in anorexia nervosa, although the exact neurobiological mechanisms are not known or understood​[77–79]​. When there is a comorbid diagnosis, care should be taken to ensure that these are considered and adequately treated if possible.  

If there is co-morbid ASC, person-centered adaptations and/or reasonable adjustments should be made to treatment to support recovery​[80]​. This may include providing a sensory friendly environment, communication-based changes (e.g. speak clearly, slowly and succinctly, using direct language) or adjustments to minimise uncertainty, such as confirmed appointment times and seeing people at the time agreed where possible. It may be that the person has an autism passport (where individuals can express how their autism effects them and detail ways that suitable adjustments can be made). If so, this should be referred to in order to support the person to engage in healthcare-related appointments and activities, as well as reduce barriers to effective treatment​[81]​.

In the case of a co-morbid diabetes diagnosis, there is risk of misuse of insulin in order to facilitate weight loss. Treatment for people with an eating disorder and diabetes should be a collaboration between eating disorder and diabetes teams, and both NICE guidance and MEED guidance, where appropriate, should be followed in order to support safe and effective treatment​[12,69]​.

Complications

There are several possible physical complications that may occur as a consequence of developing an eating disorder. In restrictive presentations and with a low BMI, there is the risk of developing low bone mineral density leading to osteopenia and osteoporosis. Guidance suggests that bone mineral density scans should be considered after one year of being underweight in children and young people and after two years of being underweight in adults​[12]​. This should be considered earlier if there is bone pain or recurrent fractures. The mainstays of therapy in this population should be restoration of weight and increase in calcium and vitamin D, ideally through diet alone, although supplementation may be appropriate where this is not possible​[82,83]​. 

Should it be necessary (for example where osteopenia has developed into osteoporosis), other treatment options are available, such as hormonal treatments (oestrogen) or bisphosphonate. However, specialist advice and support should be sought​[12]​.

If there has been significant restriction of food intake for a number of days and food (especially carbohydrates) is reintroduced, there is a risk of re-feeding syndrome. This is a potentially fatal condition that can occur when nutrition is given to people following starvation. The sudden reintroduction of food leads to metabolic disturbances that result in neurological and cardiovascular problems​[84]​. People at high risk of re-feeding syndrome (i.e. those who have a significantly low BMI), have had little to no intake for more than four days and blood abnormalities such as low electrolytes and white blood count, require high levels of monitoring and consideration should be given to managing this in a hospital setting. If risk of re-feeding is lower, this can be managed safely in community settings; however, careful medical monitoring is required​[69]​. In all cases where re-feeding syndrome could be a possibility or people with an eating disorder are admitted to medical or psychiatric wards, MEED guidance should be consulted and followed as appropriate.

Other complications as a consequence of an eating disorder include fluid and electrolyte disturbance due to over-hydration or dehydration, either from restriction of fluids or as a consequence of purging. Care should be taken during assessment to understand the eating disorder behaviours and where there is risk of fluid and electrolyte disturbances, medical monitoring should occur. If there is cause for concern, consideration should be given to the appropriate intervention (e.g. potassium supplementation in the case of hypokalaemia). Acute medical care should be given in the case of any severe physical health complication​[12]​.

When complications are less severe (for example dental problems owing to self-induced vomiting), advice on the management and prevention of this can be offered in line with NICE guidance​[12]​.