Eating disorders are among the most dangerous and difficult to treat of all mental health disorders. Eating disorders do not discriminate. They can be found in both genders, all age groups, and across a wide variety of races and ethnic backgrounds. Eating disorders adversely impact the health and well-being of those affected. And, sometimes, eating disorders can become quite severe and, without aggressive medical treatment, can lead to death.[1]

This article will explore the key features of these often misunderstood disorders.

Our unhealthy relationship with food

Were you ever told you must clean up your plate?  Or eat your Brussel sprouts before you could have dessert? If so, you aren’t alone. Many of us grew up being harangued with some variation of these types of “eat your food or else” threats. However, they are just one of many contributing factors to American’s unhealthy relationship with food. Among others are:

      • Our belief that anything enjoyable is inherently wrong
      • Thinking that things that are good for us are not enjoyable
      • Eating and dieting are national obsessions
      • Obsession with thin beauty is reinforced by the media
      • Dietary recommendations are conflicting, contradictory, and constantly changing
      • Physicians and other health professionals may not recognize there is problem until it is quite advanced

The dichotomy between good food and bad food generates fear, anxiety, and guilt. We feel guilty about eating enjoyable foods, yet we use them to lift our moods, reward behavior, and celebrate milestones. 

This mentality leads to problems with eating disorders.

Different manifestations of unhealthy relationships with food

There are different manifestations of disordered eating, including:

      • Some individuals gorge themselves into obesity
      • Others eschew food altogether.
      • Yet others gorge on food and then purge.
      • And some rigidly obsess about what they eat.

Many of us may do these things to a lesser degree or intermittently. But in some individuals, these patterns take control of their lives. At this point, we say that they have developed a serious eating disorder.

Types of eating disorders

The three types of eating disorders most discussed and researched are Anorexia Nervosa, Bulimia Nervosa, and Binge Eating. [A detailed discussion of specific diagnostic criteria can be found here.[2]

  • Anorexia Nervosa 

Anorexia nervosa is characterized by weight loss (or lack of appropriate weight gain in growing children), difficulties maintaining the right body weight, and a distorted body image. 

  • Bulimia Nervosa

Bulimia nervosa is characterized by a cycle of bingeing, self-induced vomiting, and/or laxative abuse designed to undo the effects of binge eating.

  • Binge Eating Disorder

Binge eating disorder is the most common eating disorder. It is characterized by recurrent episodes of feeling out-of-control while quickly consuming large quantities of food. Binges are accompanied by feelings of guilt and shame. Purging and laxative abuse do not occur with this disorder.  

Other subtypes of eating disorders

These disorders are not formally recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM–5.)

The pursuit of a healthy diet is considered laudable. But when fixation on eating a correct diet becomes the most critical part of one’s life, it is regarded as a disorder.

Muscle Dysphoric Disorder is sometimes referred to as “Bigorexia,” “Megarexia,” or “Reverse Anorexia.” It is not listed in DSM-5 as a separate diagnosis but rather as a subset of Body Dysmorphic Disorder.{3] While it shares several characteristics with anorexia, it is a desire to be bigger rather than smaller.

Diabulimia is not recognized as a formal diagnosis by the medical or psychiatric communities. However, it has been referred to as the world’s most dangerous eating disorder. It refers to an eating disorder in a person with diabetes, typically Type I Diabetes, wherein the person purposefully restricts insulin to lose weight.

How common are eating disorders?

The National Institute of Mental Health (NIMH) reports that binge eating disorder occurs in 1.2% of adults. The rate twice as high among females. Bulimia nervosa affects 0.3% of adults and is five times higher among females than males. The lifetime prevalence of anorexia nervosa in adults is 0.6%, and it occurs three times more among females than males. 

Many more individuals may experience the symptoms of an eating disorder but do not yet have a formal diagnosis. Also, many individuals struggle with body dissatisfaction and subthreshold disordered eating attitudes and behaviors.

Related content by the same author: Body Dysmorphic Disorder: Obsession with a Flaw Interferes with Life

What causes eating disorders?

A considerable amount of research has been done on the biological, psychological, developmental, and sociocultural risks associated with eating disorders. While the number of risk factors identified as contributing to the development of eating disorders has increased, evidence for the cause of eating disorders [5] has not been conclusive. 

Risk factors are first present in early adolescence, but eating disorders tend to emerge in late adolescence and early adulthood. Eating disorders do not present in the same way from one person to the next. However, research has found similarities in significant risks for developing eating disorders.

  • Risks for developing eating disorders

There are three variables that are commonly associated with eating disorders:

      • Perceived pressure to be thin
      • Internalizing a thin-ideal
      • Body dissatisfaction

In the last few years, research has shifted toward the genetics and neurobiology of eating disorders. Most researchers no longer believe that the cause is a matter of “will” or self-control.

  • Poor food choices

People routinely make poor choices, despite knowledge of negative consequences. Still, individuals with anorexia nervosa make bad food choices to the point of starvation.

One study found that individuals with anorexia engage a different part of their brain when making food choices compared to healthy subjects. The part of the brain identified is associated with habitual behaviors.[6]

Related Content:  5 Reasons Why Patients Ignore Doctors’ Weight Loss Advice

  • Genetics

Another report suggests a genetic model that considers environmental, nutritional, and genetic factors in eating disorders.[7] Evidence for a genetic link is supported by the fact that eating disorders occur more frequently when a close relative has an eating disorder or a mental health condition. 

  • Other risk factors:

      • Perfectionism
      • Body image dissatisfaction
      • Personal history of an anxiety disorder
      • Always following the rules
      • Weight stigma
      • History of dieting
      • Type 1 (insulin-dependent) diabetes
      • Teasing or bullying
      • Racial and ethnic minority groups 
      • Loneliness and isolation
      • Psychological trauma
      • Bullying
      • Weight stigma

Perfectionism is one of the most common risk factors for eating disorders. Eating disorder risks are higher in racial and ethnic communities, particularly for those undergoing rapid Westernization. Bullying leads to low self-esteem, isolation, and poor body image. 

Over 70% of people with eating disorders reported mental health issues.[8] The most common are anxiety disorders, followed by mood disorders, self-harm, and substance abuse. Perfectionism and negative emotions (anger, sadness, guilt, anxiety, and disappointment) are frequently associated with eating disorders.

Eating disorders in athletics

Both female and male athletes are at higher risk of developing an eating disorder compared to non-athletes [9] This is especially true for athletes participating in sports where leanness confers a competitive advantage.

Eating disorders are more prevalent in appearance-oriented athletic activities called “aesthetic sports“[10] (swimming, gymnastics, dance, and bodybuilding) than in ball sports. 

Early specialization in a sport appears to be a factor. Athletes tend to under-report their disordered eating. In combat sports like martial arts sports, athletes compete within weight classes. Disordered eating and pre-competition of rapid cutting of weight are everyday occurrences and predispose to eating disorders.

Diagnosis and treatment

Treatment begins with a good medical evaluation by a health care provider. Severe cases may require stabilization in a hospital experienced in the safe refeeding of severely malnourished individuals.[1]

Much of the psychiatric treatment of eating disorders focuses on psychotherapy with one of the following:

  • Cognitive Behavioral Therapy (CBT)

CBT is the leading evidence-based treatment for all eating disorder diagnoses in adults. It can also be adapted for adolescents. CBT is designed to produce changes in thinking. In eating disorders, it focuses on what is keeping the eating problem going. CBT includes homework exercises to complete between therapy sessions. Issues addressed include shape and weight, dietary rules, moods related to eating, perfectionism, and low self-esteem.

  • Family-Based Treatment (FBT)

FBT is the leading evidence-based treatment for eating disorders in adolescents and children. In FBT, parents play an active and positive role to help their child. 

  • Interpersonal therapy (IPT)

IPT is a time-limited, focused therapy developed for the treatment of depression that has been adapted for eating disorders. It recognizes the importance of current interpersonal relationships in the recovery process. 

  • Cognitive remediation therapy (CRT)

CRT was developed initially for patients with brain injuries. patients with eating disorders have deficits in their thinking. In particular, they have inflexible thinking. 

The Eating Disorder Assessment for DSM-5 (EDA-5) is a semi-structured interview meant to assist in assessing a feeding or eating disorder according to DSM-5 criteria. It is intended for use by clinicians who have some familiarity with the feeding and eating disorders. It is available electronically and in Spanish as well as other languages. The EDA-5 is available at no cost for use in clinical settings.

In those individuals with co-morbid mental conditions like anxiety and depression, anti-depressant medications are indicated.

Treatment outcomes

The best predictor of outcomes in treating eating disorders[11] is the degree of symptom reduction early in treatment. Other predictors of treatment success relate to

  • Body Mass Index (BMI)
  • fewer binge/purge episodes
  • higher motivation
  • lower depression
  • lower concerns about shape and weight
  • fewer comorbidities
  • better interpersonal functioning
  • fewer family problems

The bottom line 

Eating disorders are serious and, at times, life-threatening mental illnesses that require knowledge about the risk factors, causes, treatment options, and outcomes. 


    1. Mehler P. Medical Management of Severe Eating Disorders. The Doctor Weighs In, 2020 Dec 1. Accessed 12/10/20.
    2. National Eating Disorders Association. What Are Eating Disorders?  Accessed 12/10/20
    3. Veale D. Body Dysmorphic Disorder. BMJ 2015350 doi: Published June18, 2015. ( Cite this as: BMJ 2015;350:h2278)  Accessed 12/10/20. Ed. note: this reference is behind a paywall.
    4. National Institute of Mental Health. Easting Disorders. Accessed 12.10/20
    5. Rikani AA, Choudhry Z, Choudhry A et al. A critique of the literature on etiology of eating disorders. . 2013 Oct; 20(4): 157–161. doi: 10.5214/ans.0972.7531.200409
    6. Foerde K, Steinglass J, Shohamy D, et al. Neural mechanisms supporting maladaptive food choices in anorexia nervosa. Nature Neuroscience (Advancce online publication), 2015 Oct 12. doi:10.1038/nn.4136.
    7. Himmerich H, Bentley J, Carol Kan et al. Genetic risk factors for eating disorders: an update and insights into pathophysiology. Therapeutic Advances in Psychopharmacology 2019 Feb 12.
    8. Keski-Rahkonen A, Mustelin L. Epidemiology of eating disorders in Europe: prevalence, incidence, comorbidity, course, consequences, and risk factors, Current Opinion in Psychiatry: November 2016 – Volume 29 – Issue 6 – p 340-345 doi: 10.1097/YCO.0000000000000278
    9. Joy E, Kussman A, Nattiv A. 2016 update on eating disorders in athletes: A comprehensive narrative review with a focus on clinical assessment and management, British J Sports Medicine, 2015, httpss://
    10. Thiemann P, Legenbauer T, Vocks S. et al. Eating Disorders and Their Putative Risk Factors Among Female German Professional Athletes 2015 March 31.
    11. Vall E, Wade T. Predictors of treatment outcome in individuals with eating disorders: A systematic review and meta‐analysis, International J of Eating Disorders, 2015 July 14, (behind a paywall).

Severe eating disorders are the only mental illnesses regularly accompanied by dangerous, life-threatening medical complications. Significant medical instability results from a number of abnormalities, such as progressive malnutrition, purging behaviors, and blood chemistry abnormalities.

In fact, the disorder can compromise virtually all of the body’s vital organs and systems.

There are a number of different eating disorders that lead to excessive weight loss and associated medical complications. The most common include:

In this article, I will focus on the medical complications of these disorders. I will also discuss how to manage because it is crucial to saving the lives of individuals suffering with a severe eating disorder. Further, it is key to helping patients achieve the medical stability and cognitive function necessary to engage fully in the recovery process.

Related content:
What You Need to Know About Eating Disorders
Eating Disorders: Risk Factors, Diagnosis, Treatment, and Outcomes

Medical complications of severe eating disorders

Common medical complications associated with severe eating disorders include the following [1,2]:

      • Gastrointestinal complications, including diarrhea, delayed gastric emptying (gastroparesis), constipation, abdominal pain, and swallowing difficulties) 
      • Liver function test abnormalities
      • Electrolyte abnormalities
      • Pseudo-Bartter’s syndrome (a complex of metabolic abnormalities related to purging)
      • Eye pain
      • Edema
      • Osteoporosis and osteopenia,
      • Superior mesenteric artery (SMA) syndrome
      • Cardiac dysfunction & arrhythmias
      • Muscle weakness
      • Traumatic falls

Medical complications of eating disorders can be treated effectively

The good news is that nearly all medical complications of eating disorders can completely resolve with safe nutritional rehabilitation and weight restoration. This is true regardless of how extensive they are.

Patients are resilient if they get the correct (and timely) treatment with a balance of informed medical and psychiatric care. This is especially critical for more chronic patients and patients of advanced age.

The bad news, however, is that eating disorders themselves are commonly undertreated. This means that a large number of patients receive only partial treatment for the complex medical and psychiatric concerns associated with these illnesses.

It is important to understand that severe eating disorders can be deadly. Anorexia nervosa, for example, is considered the deadliest of all mental illnesses with a mortality rate estimated to be ~10%. [3]  Further, AN patients carry an increased risk for suicide.

Many patients with severe eating disorders will require a high level of care

More than one-third of individuals suffering from eating disorders will require treatment at a higher level of care. This can range from 24-hour inpatient psychiatric care to comprehensive daytime behavioral programming. 

Most treatment programs offer some degree of minimum internal medicine and/or nursing support to manage medical issues of eating disorders. However, some patients may be so medically compromised by their illness that they require specialized medical, hospital-based stabilization prior to entering a residential eating disorder treatment program.

Determining what level of care a patient with an eating disorder needs can be challenging for reasons that include:

      • patient resistance,
      • secrecy shrouding eating disorder behaviors and symptoms,
      • the body’s ability to feign stability.

Determining the appropriate level of care needed

It is not uncommon for patients, families, and providers to begin with the least intensive intervention. However, starting a treatment plan with the appropriate level of care can have a significant impact on the patient’s health. It is also a factor that influences success in recovery and satisfaction with treatment.[4]

The American Psychiatric Association (APA) has outlined five levels of psychiatric care. They are divided between outpatient and inpatient treatments.

It is important to note, however, that this guidance fails to completely outline a crucial sixth level of care. This is the one that involves specialized medical treatment for individuals experiencing extreme medical instability that results from physical complications of malnutrition and purging. 

For this severe subset of patients, intervention should include medical stabilization in a specialized, hospital-based medical unit prior to beginning traditional behavioral eating disorder treatment.

Expert consensus suggests inpatient stabilization should occur when a BMI is <14 or when that patient’s weight is <70% of ideal body weight (IBW).

  • Weight specific recommendations to levels of care

In general, patients with AN or Avoidant/Restrictive Food Intake Disorder (ARFID) whose weight is:

      • below 70% IBW should first be treated in a specialized medical unit for the medical stabilization of those patients,
      • between 70 to 84% of IBW, are best served in an inpatient or residential treatment center,
      • between 85% to 95% of IBW, a partial hospitalization program (PHP) is generally appropriate.[5]

It is important to remember that no guideline is absolute when it comes to these complex illnesses. The frequency of purging behaviors and other physical or psychiatric symptoms must be considered alongside patient weight to ascertain the appropriate level of care that may be needed.

What is inpatient medical stabilization for eating disorders?

In general, initial medical stabilization in a hospital-based unit is recommended for eating disorder patients who are severely low weight, seriously medically compromised, or at risk for major complications from refeeding syndrome. The latter is a dangerous metabolic disturbance that can occur when nutritional rehabilitation is first initiated.

Patients with any/all of the following criteria may require medical treatment from experienced providers in a specialized medical hospital unit before entering a behavioral treatment program in a traditional eating disorder unit:

      • weight <70 percent of ideal body weight or BMI <14
      • unstable vital signs such as low or irregular heart rates or low blood pressure
      • cardiac disturbances such as abnormal heart rhythms or heart failure
      • loss of consciousness due to low blood pressure
      • acute kidney or liver failure and/or
      • critical electrolyte abnormalities such as low potassium or low phosphorous of extreme degrees.

What is the goal of medical stabilization of patients with severe eating disorders?

The goals of medical stabilization are to improve and normalize the patient’s vital signs, cardiovascular system, and bowel function as well as restore levels of key electrolytes including phosphorus, potassium, magnesium, and calcium in a timely manner. Medical stabilization also involves nutritional rehabilitation to support weight restoration.

Most experts agree that careful caloric initiation is vital to medical stability and improved cognitive function. It is hallmarked by the ability to tolerate and complete the most basic activities of daily living. Inpatient medical units have the expertise and resources to deliver any form of nutrition required, including oral, enteral, or intravenous calories.

It is important that each of these goals is met in order for a patient with an eating disorder to be considered medically stable. Once the patient has achieved medical stability, he or she can continue in recovery by transitioning to a 24-hour psychiatric facility. It is important that the psychiatric facility has the ability to sustain medical progress while incorporating the following interventions:

      • intensive psychotherapy,
      • ongoing weight restoration,
      • other evidence-based recovery interventions.

Understanding the difference between medical and psychiatric treatment 

It is also important that providers, patients, and families understand the difference between inpatient psychiatric treatment and inpatient medical stabilization for the most severe eating disorders.

While an inpatient psychiatric facility offers round-the-clock behavioral treatment and likely some degree of medical support, an inpatient medical stabilization program requires a hospital-based telemetry unit.

Its full-time internal medicine physicians, nurses, dietitians, and skilled rehabilitation providers expertly treat any life-threatening medical complication of severe eating disorders. These medical teams collaborate with psychiatrists, psychologists, and behavioral health technicians to support behavioral recovery.

It is important for patients and families to understand that patients with serious complications due to eating disorders will be too weak, medically unstable, or cognitively impaired to engage in meaningful therapy during medical hospitalization.

Inpatient medical and inpatient psychiatric programs must work together to support survival and recovery in medically complex patients. Initially, however, there is no substitute for 24/7-available medical, dietary, and nursing expertise on a dedicated medical stabilization unit.

Avoiding refeeding syndrome

Increasing caloric intake quickly in individuals with severe anorexia nervosa or ARFID, without frequent monitoring of blood tests and electrolyte replenishment, can lead to refeeding syndrome. A dangerous shift in fluids and electrolytes within the body are characteristic of the disorder.

It occurs in a small subset of patients when calories are introduced quickly, lab tests are not checked frequently, and resultant abnormalities are not treated in a timely fashion. The lower the patient’s BMI, the greater the risk of refeeding complications.[6]  

  • Cardiac complications of refeeding

When the body is starved or severely malnourished, the heart muscle may atrophy. This causes diminished cardiac output. Further, the body begins to break down its own tissues—including fats and muscle—in an attempt to create the energy needed to maintain basic bodily functions. These changes can affect the body’s major electrolytes, including phosphorus, potassium, and magnesium.

  • A shift to carbohydrate metabolism

When food is reintroduced during the refeeding process, there is an abrupt shift from fat and muscle metabolism back to carbohydrate metabolism.  This increases the body’s uptake of phosphorus and other key electrolytes into newly developed cells. This leads to dangerously decreased levels of these electrolytes in the blood.

This sudden change in the balance of electrolytes causes the atrophied heart to work harder, which can cause irregular heartbeat, muscle damage, weakness, seizures, and even death. When the resultant blood chemistry abnormalities are not detected or are not addressed in less than a few hours, patients may be at risk for the refeeding syndrome characterized by the following:

        • cardiac failure, 
        • respiratory failure,
        • rhabdomyolysis (muscle death),
        • hemolysis (red blood cell rupture) and/or
        • seizures.

These life-threatening complications are preventable when refeeding is administered by eating disorder experts. However, many medical providers are not trained to identify or address refeeding syndrome in patients with extreme anorexia and ARFID. This unfortunate reality underscores the need for severely underweight patients to begin the refeeding process in a specialized inpatient medical setting capable of treating the most serious eating disorders.

Eating disorder patients with normal or high BMI

Assuming that patients with a “normal” or “higher” BMI are always stable enough to access lower levels of care may inadvertently cause harm. Some of these patients may present with a falsely elevated weight.

They can also be at risk for dangerous complications due to excessive purging behaviors followed by abrupt cessation or significant and rapid “weight disruption” that is marked weight loss over a short period of time.[6]

Thus, regardless of current weight, it is essential to consider the severity of purging behaviors and absolute weight loss when choosing an appropriate level of care.

Again, consider medical stabilization first for those showing severe weight disruption (more than 25% body weight loss in a short time period). Include as well those needing to safely “detox” from severe self-induced vomiting and laxative or diuretic abuse.

The bottom line on the management of severe eating disorders

Eating disorders at any stage are complex and can be life-threatening. Seeking treatment for a severe eating disorder can be overwhelming. This is especially true when life-threatening medical complications are present. However, helping providers, patients, and families understand which level of care provides adequate medical support to address these complications and restore medical stability is an important first step in the recovery journey.


1. Cost J, Krantz M, Mehler P. Cleveland Clinic Journal of Medicine, Medical complications of anorexia nervosa. (2020) 87 (6) 361-366; DOI:

2. Mehler, P. International Journal of Eating Disorders, Medical complications of bulimia nervosa, and their treatments. (2011) 44(2):95-104. DOI: 

3. Berends, T, Boonstra N, van Velburg A. Current Opinions in Psychiatry, Relapse in anorexia nervosa: a systematic review and meta-analysis. (2018) 31(6): 445-455. Doi: 10.1097/YCO.

4. Cost J, Mehler P. Eating Disorders Review, Level of Care Considerations for Severe and Extreme Eating Disorders. (2019), Vol 30. 

5. Mehler P, Crews C. Eating Disorders-The Journal of Treatment and Prevention, Refeeding the Patient With Anorexia Nervosa. (published online 2010)

6 Garber, A. K.. Journal of Adolescent Health. Moving beyond “skinniness”: presentation weight is not sufficient to assess malnutrition in patients with restrictive eating disorders across a range of body weights. (2018), 63(6), 669-670.