Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

medically stable and suitable for outpatient treatment

1st line – structured eating plan with oral nutrition

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ACUTE
|
medically stable and suitable for outpatient treatment
1st line – 

structured eating plan with oral nutrition

In determining the patient’s initial level of care, or whether to change to a different level of care, consider a number of factors including their overall physical condition, behaviors and cognitions, affective state, and social circumstances.[66] Structured outpatient programs are appropriate for outpatients who require some meal supervision and other supports, whose weight and health status is not severe enough to require residential or hospital care.

Nutritional rehabilitation for individuals with AN requires a nutritionally balanced meal plan with adequate calories for weight restoration, with the aim of restoring weight, normalizing eating patterns, and achieving normal perceptions of hunger and satiety. Once weight restoration has been achieved, maintenance of a healthy weight range is key.[66]

Starting nutritional rehabilitation may be very frightening and can be associated with intensely distressing feelings for patients; psychosocial support through this with conveyance of empathy and compassion is a cornerstone of effective treatment.[67] 

Nutritional rehabilitation for individuals with AN requires a nutritionally balanced meal plan with adequate calories for weight restoration.

Dietary assessment and guidance by a registered dietitian/nutritionist skilled with specific expertise in AN is helpful to identify specific deficiencies and to develop an optimal plan.[66]

Guidelines on initiation of caloric prescription vary significantly, and international practices vary; note that patients with risk factors for refeeding syndrome may require slower rates of caloric increase (see below). Many clinics now use higher initial caloric prescriptions than have been used historically (e.g., 1500-2000 kcal/day) and faster rates of renourishment because the literature has not shown an association between higher caloric intake during nutritional rehabilitation and the development of refeeding syndrome when patients are under close medical monitoring with electrolyte correction (e.g., for hypophosphatemia) as needed.[66]

Caloric prescriptions may increase by 400 kcal/day every 48-72 hours if patients tolerate prior caloric level. Peak caloric requirements in treatment programs that aim to help patients achieve full weight restoration typically reach between 3000 and 4000 kcal/day. Meal plans may include liquid supplements as snacks in addition to solid foods.[89][90]

Vitamins and minerals (e.g., multivitamin, phosphorus, magnesium, and calcium) should be given until the patient’s diet contains enough to meet his or her dietary reference values.[65] Thiamine supplementation should be considered.

Fluid intake should be monitored. During treatment, patients may consume large quantities of water in order to falsely elevate weights. Additional supervision and/or urinalysis for specific gravity determination may be necessary for successful refeeding with appropriate levels of fluid consumption.

It is recommended that an individually determined target for weight is established as part of the initial treatment plan.[66] Factors to guide this target include body mass index (BMI) guidelines (e.g., BMI >20 kg/m²), commonly available weight-for-height tables (e.g., Metropolitan Life Actuarial Tables), the individual’s pre-illness weights, or, for younger patients, their growth charts.[80]​ In adolescents, target weight will need to be adjusted upward to correspond to increases in the patient’s height, and it can be helpful to discuss this with them from the initiation of treatment. During a period of growth, it is recommended that the target weight be reassessed every 3-6 months.[66]

Typically the target weight will be discussed explicitly with the patient, but this can require considerable sensitivity; it may be sensible to delay this discussion in some circumstances, until the person with AN is less fearful of their ultimate weight.[66] Clinical consensus suggests that realistic targets are 2-4 lb/week for patients in residential or inpatient programs, at least 1-3 lb/week for patients in partial hospital programs, and at least 1-2 lb/week for individuals in outpatient programs.[66] Outpatients should be weighed weekly. Patients should be weighed using consistent procedures. For example, patients should be weighed at a consistent time of day (e.g., early morning postvoiding, prebreakfast), in such a manner as to minimize manipulation of weight data (e.g., wearing a hospital gown or light clothing). People with AN may require support and sensitivity during weighing procedures as these are frequently associated with anxiety and distress. Note that patients differ in the extent to which they wish to be informed of their weight, with some wanting to know specific values and others wanting only to know whether they have met their weekly weight targets.[66]

Plus – psychotherapy

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ACUTE
|
medically stable and suitable for outpatient treatment
Plus – 

psychotherapy

Treatment recommended for ALL patients in selected patient group

It is recommended that all adults with AN are treated with an eating disorder-focused psychotherapy. Timing of this should be individualized based on the individual’s level of medical stability and willingness to engage with psychological treatment; for example, for people who are severely malnourished, attempts to conduct formal psychotherapy may be ineffective.​[66]​

While several psychological treatments have been examined in adult patients, no single approach has demonstrated clear superiority.[95]

Behavioral management is commonly recommended and effective in structured treatment settings.[96]

Outpatient strategies that have a modest evidence base for improving outcome (associated with moderate weight increases, although not to fully normalized weight ranges) include cognitive behavioral therapy (CBT) and specialist supportive clinical management (SSCM).[97][98] These are commonly offered as part of structured treatment approaches for AN, or as outpatient treatments.

Maudsley Anorexia Nervosa Treatment for Adults (MANTRA) has been found in one randomized controlled trial to be equally effective to SSCM, and more acceptable to patients, at 12 months.[100]

Following weight restoration, individuals with AN benefit from ongoing treatment aimed at preventing relapse. Again, there is no specific treatment with a strong evidence base for this phase of treatment, but ongoing behaviorally focused treatment aimed at maintaining normal weight and eating behaviors is generally accepted as useful during the year following acute weight normalization.[107][108]

For children and adolescents, family-based treatment (FBT) is often an effective intervention, and it is recommended as a first-line option for all those with AN who have an involved caregiver.[65][66][70] Multiple studies have demonstrated that a family-based outpatient approach to refeeding adolescents with AN is associated with high rates of full remission of symptoms at the end of treatment and at 1 year following presentation, and is modestly better than individual outpatient psychotherapy focused on general adolescent issues.[101][102][103][104]

If AN-focused family therapy is unacceptable, contraindicated, or ineffective, the second-line recommendations are individual eating disorder-focused cognitive behavioral therapy (CBT-ED) or adolescent-focused psychotherapy for AN (AFP-AN).[65]

Consider – oral potassium supplementation

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ACUTE
|
medically stable and suitable for outpatient treatment
Consider – 

oral potassium supplementation

Treatment recommended for SOME patients in selected patient group

Hypokalemia is often the result of purging by vomiting and/or laxative misuse. Repletion for those with potassium levels >3.2 mEq/L can usually be achieved with foods alone if purging behaviors are interrupted. For lower levels, or for patients who are still purging, oral supplementation is generally helpful, and may be required for several days. Intravenous potassium chloride may be given together with fluids for significant hypokalemia (e.g., <2.8 mEq/L) when patients present to intensive medical settings. Simple replacement may provide adequate correction, but if refractory, may be due to concomitant hypomagnesemia or hypocalcemia. These deficits must be corrected first, and consultation with internal medicine is recommended.[92][94]

medically unstable or outpatient failure

1st line – inpatient admission ± oral, enteral, or parenteral nutrition

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ACUTE
|
medically unstable or outpatient failure
1st line – 

inpatient admission ± oral, enteral, or parenteral nutrition

Any patient with a severe eating disorder can deteriorate rapidly and should be referred immediately for specialist care.[67] Many patients will require acute inpatient medical stabilization and management of medical complications associated with the presenting illness.

Inpatient care is generally recommended for patients with: life-threatening weight loss (e.g., BMI <15 in adults or <75 % of median BMI for age and sex in children and adolescents); precipitous loss of weight (e.g., recent loss of >1 kg for two consecutive weeks); evidence of medical complications of illness, including significant bradycardia (e.g., pulse <50 bpm), hypotension or postural drop (e.g., >20 mmHg) with dizziness, hypothermia (e.g., core temperature <96.8°F, abnormal ECG results (e.g., prolonged QTc >450 or other significant ECG abnormalities) or with evidence of cardiac failure; laboratory abnormalities (e.g., low sodium, potassium, phosphate, magnesium, or glucose); evidence of refeeding syndrome, or at high risk for refeeding syndrome; an indication for compulsory treatment under mental health legislation due to refusal of life-threatening treatment; psychiatric instability including suicidality or psychosis.[66][67]​​​[85][93]

Guidelines are available that provide a comprehensive list of parameters supporting the need for medical or psychiatric inpatient hospitalization, according to whether the person with anorexia is a child or adult. Clinicians should be familiar with the applicable local guidance based on their practice location.[66][67]​ Hospital care may be either within medical or psychiatric facilities depending on the degree and severity of physical symptoms, and the experience of the unit in managing malnutrition.[83] Patients treated in a medical facility should ideally have ongoing support from a consultant psychiatrist with experience and training in the management of severe eating disorders, to work in partnership with the physician responsible for their medical care. While voluntary admission to hospital is always preferred, involuntary treatment may be necessary for the treatment-refusing patient who is medically or psychiatrically unstable.[65][85]

Starting nutritional rehabilitation may be very frightening and can be associated with intensely distressing feelings for patients; psychosocial support through this with conveyance of empathy and compassion is a cornerstone of effective treatment.[67]

Nutritional rehabilitation for individuals with AN requires a nutritionally balanced meal plan with adequate calories for weight restoration, with the aim of restoring weight, normalizing eating patterns, and achieving normal perceptions of hunger and satiety. Furthermore, in those who are seriously underweight, malnourished, or medically unstable, goals of nutritional treatment are to restore medical stability (e.g., normalizing vital signs, electrolytes, and fluid balance), and to correct biological and psychological sequelae of malnutrition. Once weight restoration has been achieved, maintenance of healthy weight range is key.[66]

Caloric prescription can commonly begin at significantly higher levels than the patient had been consuming prior to treatment.[88] Guidelines on initiation of caloric prescription vary significantly, and international practices vary; note that patients with risk factors for refeeding syndrome may require slower rates of caloric increase (see below). Many clinics now use higher initial caloric prescriptions than have been used historically (e.g., 1500-2000 kcal/day) and faster rates of renourishment because the literature has not shown an association between higher caloric intake during nutritional rehabilitation and the development of refeeding syndrome when patients are under close medical monitoring with electrolyte correction (e.g., for hypophosphatemia) as needed.[66] Caloric prescriptions may increase by 400 kcal/day every 48-72 hours if patients tolerate prior caloric level. Peak caloric requirements in treatment programs that aim to help patients achieve full weight restoration typically reach between 3000 and 4000 kcal/day. Meal plans may include liquid supplements as snacks in addition to solid foods.[89][90]

Patients with risk factors for refeeding syndrome (e.g., those with very low weight <70% average body weight, preexisting electrolyte or renal abnormalities, infection or other medical complications) require lower initial caloric intake, with caloric increases over a longer period of time, in order to mitigate this risk.[67][88]

Vitamins and minerals (e.g., multivitamin, phosphorus, magnesium, and calcium) should be given until the patient's diet contains enough to meet his or her dietary reference values.[65] Thiamine supplementation should be considered.

Dietary assessment and guidance by registered dietitian/nutritionist skilled with specific expertise in AN is helpful to identify specific deficiencies and to develop an optimal plan.[66]

Oral feeding is preferred, but some patients may not gain weight when fed orally, or may express a preference for nasogastric feeding.[67] Use of nasogastric feeding can be associated with complications such as nasal irritation, epistaxis, electrolyte disturbance, patient distress, and patient-initiated nasogastric tube removal. 

Consequently, it is recommended that nasogastric tube feeding is viewed as a short-term intervention with the goal of transitioning to oral intake.[66] Some patients may have fewer gastrointestinal symptoms with tube feeding via the small intestine and use of a Dobhoff or "duo" tube. This can be more effective than oral refeeding, but less acceptable, and is associated with an increased risk of refeeding syndrome compared with oral feeding.[123] If the patient attempts to remove the tubing, surgically placed tubing, such as a gastrostomy or jejunostomy tube, may be considered; however, the use of such an approach is not preferred.[66] Total parenteral nutrition is recommended only as a treatment of last resort when all other options for nutritional supplementation have been attempted; it requires intensive medical monitoring and is associated with an increased risk of serious adverse effects including hepatic injury, sepsis, disseminated intravascular coagulation, and refeeding symdrome.[66] Degree of voluntariness regarding treatment, competency for clinical decision-making, and legal construct for involuntary treatment are common considerations for individuals who require feeding by surgically placed tubes. If a patient with AN declines treatment when their physical health is seriously compromised by their illness, involuntary treatment may become necessary as a last resort.[65][85] This is ethically and clinically justified only when a patient’s decision-making capacity regarding appropriate treatment for their eating disorder is impaired, the risk of death or serious morbidity is high, and the likelihood of benefit from involuntary treatment outweighs the risk of harm.[66]

In this scenario, clinicians should utilize the legal frameworks for compulsory treatment appropriate to their country of practice. If a child or young person with AN refuses treatment in the context of serious medical compromise, parents or caregivers will usually serve as guardians for such minors, consenting on behalf of their children, and if necessary, using an appropriate legal framework for compulsory treatment. Feeding people without their consent should only be performed within appropriate legal constructs, and should only be carried out by multidisciplinary teams who are competent to do so and who are trained in safe control and restraint techniques.[65][67]

During the refeeding process, laboratory values, including phosphate and glucose, vital signs, including weight, and other evidence of excessive fluid accumulation, should be closely monitored and consultation with internal medicine is typically necessary. For inpatients, laboratory values should typically be monitored daily initially (twice daily in the presence of risk factors for refeeding syndrome).[67]

Patients with nasogastric or intravenous methods are at higher risk for refeeding syndrome and need to be carefully monitored. Immediate attention is necessary if there are changes in mental status, tachycardia, congestive heart failure, abdominal pain, prolonged QT interval, serum potassium levels <3 mEq/L (<3 mmol/L), and serum phosphate levels <2.5 mg/dL (<0.8 mol/L).[93] A patient with refeeding syndrome will typically need to be managed by a physician experienced in managing this life-threatening complication and may need to be in the intensive care unit.

Plus – psychotherapy

Back
ACUTE
|
medically unstable or outpatient failure
Plus – 

psychotherapy

Treatment recommended for ALL patients in selected patient group

It is recommended that all adults with AN are treated with an eating disorder-focused psychotherapy. Timing of this should be individualized based on the individual’s level of medical stability and willingness to engage with psychological treatment; for example, for people who are severely malnourished, attempts to conduct formal psychotherapy may be ineffective.​[66]​

While several psychological treatments have been examined in adult patients, no single approach has demonstrated clear superiority.[95]

Behavioral management is commonly recommended and effective in structured treatment settings.[96]

Following weight restoration, individuals with AN benefit from ongoing treatment aimed at preventing relapse. Again, there is no specific treatment with a strong evidence base for this phase of treatment, but ongoing behaviorally focused treatment aimed at maintaining normal weight and eating behaviors is generally accepted as useful during the year following acute weight normalization.[107][108]

For children and adolescents, family-based treatment (FBT) is often an effective intervention, and it is recommended as a first-line option for all those with AN who have an involved caregiver.[65][66][70] Multiple studies have demonstrated that a family-based outpatient approach to refeeding adolescents with AN is associated with high rates of full remission of symptoms at the end of treatment and at 1 year following presentation, and is modestly better than individual outpatient psychotherapy focused on general adolescent issues.[101][102][103][104]

If AN-focused family therapy is unacceptable, contraindicated, or ineffective, the second-line recommendations are individual eating disorder-focused cognitive behavioral therapy (CBT-ED) or adolescent-focused psychotherapy for AN (AFP-AN).[65]

Consider – fluid and electrolyte correction

Back
ACUTE
|
medically unstable or outpatient failure
Consider – 

fluid and electrolyte correction

Treatment recommended for SOME patients in selected patient group

Fluid intake should be monitored. Initially the patient may not have adequate fluid intake, especially if symptoms include fluid loss from purging behaviors. During treatment, patients may consume large quantities of water in order to falsely elevate weights being monitored as part of a behavioral plan. Additional supervision and/or urinalysis for specific gravity determination may be necessary for successful refeeding with appropriate levels of fluid consumption.

Hypokalemia is often the result of purging by vomiting and/or laxative misuse. Repletion at the start of refeeding should occur, with a minimum intake of 65 mmol/day. Simple replacement may provide adequate correction, but if refractory, may be due to concomitant hypomagnesemia or hypocalcemia. These deficits must be corrected first, and consultation with internal medicine is recommended.[92][94]

Oral supplementation of potassium, if possible, is the best option. Intravenous supplementation with potassium chloride plus fluids may be necessary when potassium chloride levels are very low (e.g., <2.8 mEq/L) when patients present to intensive medical settings.

Hypokalemia refractory to replacement with potassium may be due to concomitant hypomagnesemia. This deficit must be corrected first with magnesium supplementation; oral supplements may be used with caution as diarrhea may result, further offsetting fluid balance. Consultation with internal medicine is recommended.[92][94]

Hypokalemia refractory to replacement with potassium may be due to concomitant hypocalcemia. This deficit must be corrected first with calcium supplementation; consultation with internal medicine is recommended.[92][94]

Consider – olanzapine

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ACUTE
|
medically unstable or outpatient failure
Consider – 

olanzapine

Treatment recommended for SOME patients in selected patient group

Several studies in recent years have found that low-dose olanzapine may help acutely ill patients increase weight modestly, compared with placebo.[109][110][111][112]​ The rate of increase is modest, of the order of 1 to 2 pounds per month. Olanzapine is generally very well tolerated with little to no evidence of the metabolic complications associated with the use of olanzapine in other populations. Unfortunately, olanzapine does not have a significant impact on the psychological disturbances characteristic of AN.

There are very few reports of the use of olanzapine in adolescents.[109] Care should be taken to decrease and discontinue treatment when the patient is near ideal body weight. Atypical antipsychotic medications can be associated with prolonged QTc interval.[114] Thus, prior to use of olanzapine, an ECG should be performed and repeated periodically during treatment. Patients typically require significant support and reassurance before they are willing to accept treatment with olanzapine because of fears of excessive weight gain.[111]

Primary options

olanzapine: consult specialist for guidance on dose

Consider – specialist referral for management of comorbidities

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ACUTE
|
medically unstable or outpatient failure
Consider – 

specialist referral for management of comorbidities

Treatment recommended for SOME patients in selected patient group

Suicidal ideation is common; 20% of deaths amongst adults with AN are attributable to suicide.[69] Suicidality or evidence of self harm indicate a need for urgent psychosocial evaluation.[67] Mood, anxiety disorders, and obsessive compulsive disorder are the most common comorbidities in patients with AN. Substance use disorders may also be comorbid with AN. Substance use is more prevalent in individuals with the binge-eating/purging subtype than in those with the restricting subtype.

Comorbidities may be difficult to diagnose because of the symptom overlap between AN and these conditions. Selective serotonin reuptake inhibitors (SSRIs) and other antidepressant medications may not be as effective when low weight is present.[120] Weight gain is typically associated with significant improvement in comorbid symptoms, including depression and obsessionality. Normalization of weight prior to confirming mood and/or anxiety disorder diagnoses is therefore strongly recommended.

In particular, patients with AN typically exhibit cardiovascular abnormalities when low in weight, such as orthostatic hypotension, bradycardia, and prolonged QT interval. Avoid medications with known adverse cardiac effects until cardiovascular abnormalities have resolved. Medications with potentially adverse effects include SSRIs (e.g., citalopram, escitalopram), atypical antipsychotics (e.g., olanzapine), and tricyclic antidepressants (e.g., clomipramine).[121][122]

If significant comorbid symptoms persist following full weight restoration and suggest the existence of a comorbid condition, psychological and pharmacologic treatment should be based on evidence-based interventions for the condition. Specialist consultation is recommended.

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Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

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