Eating disorders are serious psychological or behavioral conditions causing avoidant, restrictive, or excessive forms of eating. There are several types of eating disorders, all of which can have serious impacts on mental and physical well-being.

Types of eating disorders

Anorexia nervosa

There are two types of anorexia nervosa: restrictive and binge-purge [1]. People with restrictive anorexia nervosa purposefully limit their calorific intake significantly due to a fear of gaining weight, which can cause extreme thinness and malnutrition.

People with binge-purge anorexia nervosa also fear weight gain, but rather than restricting nutritional intake, they will binge eat, followed by extreme exercise, vomiting, use of laxatives, or a combination of these, to prevent weight gain.

People with anorexia nervosa have a body mass index (BMI) of under 18, meaning they are underweight. This can cause several serious physical health problems, including issues with heart and brain function, organ failure, and infertility. In addition, people with this disorder are at a high risk of death due to medical conditions or suicide [2].

Typically, anorexia nervosa develops in late adolescence and is more common in females than males [3]. If someone meets the criteria for anorexia but has a BMI of over 18.5, they may be diagnosed with atypical anorexia nervosa.

Symptoms of anorexia nervosa include:

  • Fear of food
  • Fear of gaining weight
  • Distorted body image and low self-esteem regarding body image
  • Eating very little
  • Excessive exercising
  • Irregular or no periods in females
  • Stomach upset

Bulimia nervosa

Typically, people with bulimia nervosa binge eat, consuming large amounts of food very fast, feeling that they are not in control of their eating, and then engaging in inappropriate compensatory behaviors. These compensatory behaviors could include making themselves vomit, fasting for several days, using laxatives or diuretics, or engaging in excessive exercise [1].

While binge-purge anorexia and bulimia are both disorders involving binge eating followed by purging, anorexia is diagnosed in those with a low BMI, while people with bulimia are of normal weight, overweight, or obese. Therefore, they are different diagnoses, and the two disorders do not occur together [4].

Bulimia nervosa is most often diagnosed in adolescence and is more common in females than males [5]. For a diagnosis of bulimia, episodes of binge eating followed by inappropriate compensatory behaviors must occur at least once per week for three months [1].

Symptoms of bulimia nervosa include:

  • Regular binge eating
  • Regular vomiting
  • Recurrent fasting
  • Use of laxatives
  • Sore throat and swollen glands
  • Tooth decay
  • Stomach upset
  • Dehydration
  • Electrolyte imbalance from frequent vomiting, which can cause heart attack or stroke
  • Inability to lose weight
  • Low self-esteem regarding body image

Binge eating disorder

Binge eating disorder, like bulimia nervosa, is categorized by excessive eating within a certain period. However, unlike bulimia, this binge eating episode is not usually followed by inappropriate compensatory behaviors such as vomiting or fasting [6].

People with binge eating disorder will eat even when they are full or do not feel hungry, may eat very fast, eat until they are uncomfortably full, and eat alone or away from others.People with this eating disorder often experience shame and guilt associated with their binge eating episodes [1].

They may make frequent attempts to diet or exercise but will struggle to maintain these efforts and tend not to lose weight. In addition, there may be infrequent fasting or self-induced vomiting in an attempt to prevent weight gain, but this is not a common behavior within this disorder.

Binge eating disorder can affect males and females but is more common in females [5]. For a diagnosis of binge eating disorder, episodes of uncontrollable binge eating will be present at least once per week for three months.

Binge eating disorder can cause people to gain weight, leading to several health complications, such as diabetes, heart conditions, and stomach and digestive issues. In addition, it may also lead to mental health conditions such as depression and anxiety [6].

Rumination disorder

Rumination disorder or syndrome is a rare condition that has historically been difficult to diagnose due to similarities with various other medication conditions. It is still not fully understood in the medical community and the cause is not known [7].

Rumination disorder is categorized by the automatic regurgitation of foods up to two hours after eating [1]. The food that is regurgitated is not digested and thus retains the original taste of the eaten food, rather than becoming acidic. The food will then be spat out or chewed and swallowed again.

The regurgitation of food is a voluntary behavior, thought possibly to be learned and repeated until it becomes habitual. However, it is not intending to prevent weight gain, and there is no association with a distorted body image, so in this way, it is very different from other eating disorders.

Rumination disorder does not cause much physical damage to the body, rarely causing weight loss or issues in the esophagus. However, symptoms can worsen, potentially leading to physical harm [8].

As it is a behavioral condition, the treatment of rumination disorder requires relearning how to eat properly without prompting regurgitation, which a behavioral psychologist can teach. Depression, anxiety, or stress-related conditions may occur alongside rumination disorder, which requires psychological intervention to help alleviate the symptoms of the disorder [7].

Avoidant/restrictive food intake disorder

Avoidant/restrictive food intake disorder (ARFID) is a condition that typically occurs in children and adolescents but can be present in people of any age. It is not related to a distorted body image or desire to lose weight or prevent weight gain but often results in weight loss [1].

People with ARFID are picky or selective about their foods , typically eating only very specific foods. They tend to have very little interest in food or most foods, and so eat limited amounts.

As such, they receive a much lower caloric intake than is required for body growth and development or physical maintenance and may lose weight and experience stomach pain and other digestive issues [9].

This condition may be caused by a previous experience of choking or seeing someone else choke or a similarly traumatic event related to eating, creating a fear of food.

Pica

Pica is a compulsive eating disorder in which people consume items that are not of nutritional value and are not considered food [1]. This could include clay, plastics, eggshells, charcoal, and paper. Pica occurs most regularly in children and pregnant women but can affect anyone [10].

It may be a medical or psychological condition, and the cause of its development is not clearly known. Some studies suggest that pica is linked to obsessive-compulsive disorder (OCD), schizophrenia, developmental disorders, or iron deficiency. It may also occur as a condition on its own, with no other coexisting condition [11].

Pica can cause physical harm, particularly if the ingested item is lead-based, causing lead poisoning. Similarly, ingested items may cause issues with digestion, so these items must be eliminated from the body.

What are the signs of eating disorders?

As eating disorders differ, either extensively or minimally, the signs of their development may also differ. However, the following lists may indicate an eating disorder [5].

Behavioral

  • Eating alone
  • Distorted body image
  • Low self-esteem related to body image
  • Counting calories
  • Compulsive exercising
  • Picky or selective eating
  • Frequent dieting with no weight loss
  • Inability or unwillingness to gain weight
  • Isolating after meals
  • Thoughts of suicide

Physical

  • Appearing very thin
  • Weight gain or loss
  • Pale, yellow, or dry skin
  • Body hair growth or hair loss
  • Feeling very cold and tired
  • Tooth decay
  • Lack of menstrual periods

What causes eating disorders?

Eating disorders can be caused by several factors, including:

Genetic

There is some evidence to suggest that eating disorders are genetic, with increased risks in children with a parent with an eating disorder [12].

Biological

Research suggests that there are changes in brain activity in people with eating disorders in areas that affect appetite, fear, and habitual behaviors. There may also be a reduction of dopamine and serotonin in those with an eating disorder, impacting their mood, reward centers, and perceptions of self-image [3][4].

Psychological

There is a high prevalence of childhood trauma and abuse in people with anorexia nervosa [13], suggesting that trauma increases the risk of developing an eating disorder.

Social

Social and environmental factors may also play a part in the development of an eating disorder, such as being bullied in childhood for being overweight, comments from friends and family about eating behaviors or appearance, and how beauty is often portrayed in the media as thinness.

How are eating disorders diagnosed?

When diagnosing an eating disorder, a doctor will conduct a full examination to determine a full mental and physical health history of the patient and their family, any current medications, and complete a full physical health check, including blood and hormone tests, blood pressure, and weight [3][4].

The doctor will be required to rule out any other physical or mental health conditions before diagnosis, as many conditions can cause weight loss or gain, vomiting, and other symptoms seen within eating disorders. In addition, they will likely ask several screening questions relating to thoughts about food, body image, and self-worth [5].

How are eating disorders treated?

Therapy

Cognitive Behavioral Therapy (CBT) is very useful in treating eating disorders, as it focuses on changing negative thought patterns and associated behaviors, helping to reduce the symptoms of various eating disorders [5][14].

Psychotherapy can help reduce the disorder’s underlying causes and associated challenges, including poor self-image, distorted body image, depression, and anxiety [14].

Nutrition therapy may be required to help promote eating in a safe and structured way by a professional who is aware of the potential difficulties that may be encountered by someone with an eating disorder [15]. This may be individual therapy, as a group, in a hospital, or as an outpatient.

Family therapy has been found to be very useful for pediatric patients with eating disorders, helping the whole family understand and manage the condition, symptoms, and behaviors [2].

Medications

Medications are not typically used initially in treating eating disorders, as they may not be effective and can be unsafe for people with these conditions. However, occasionally antidepressant medications are used to treat symptoms of depression in patients with eating disorders, particularly fluoxetine [5].

Olanzapine is occasionally used to help with weight gain in patients with anorexia nervosa. Still, other antipsychotic medications, if required, are used with caution due to the increased risks in those who are malnourished and underweight.

Physical health monitoring

Eating disorders can cause serious health problems, including heart attacks, organ failure, stroke, and osteoporosis (weak bones). As such, people with eating disorders may require careful physical health monitoring to ensure their safety and prevent serious conditions from occurring.

Hospital

In the most severe cases, a person with an eating disorder may require hospitalization to safely increase their body weight, treat physical health concerns, or prevent harmful behaviors [3][5].

Resources:

  1. American Psychiatric Association. (2013, text revision 2022). Feeding and Eating Disorders. In The Diagnostic and Statistical Manual of Mental Disorders(5thed., text rev.). APA. Retrieved from  https://doi.org/10.1176/appi.books.9780890425787.x10_Feeding_and_Eating_Disorders
  2. National Institute of Mental Health. (Reviewed 2021). Eating Disorders. NIH. Retrieved from https://www.nimh.nih.gov/health/topics/eating-disorders
  3. Moore, C.A., & Bokor, B.R. (2022). Anorexia Nervosa. In StatPearls[Internet].Treasure Island, FL: StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK459148/
  4. Jain, A., & Yilanli, M. (2022). Bulimia Nervosa. In StatPearls[Internet].Treasure Island, FL: StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK562178/
  5. Herpertz, S., Hagenah, U., Vocks, S., von Wietersheim, J., Cuntz, U., Zeeck, A., German Society of Psychosomatic Medicine and Psychotherapy, & German College for Psychosomatic Medicine. (2011). The Diagnosis and Treatment of Eating Disorders. Deutsches Arzteblatt International108(40), 678–685. Retrieved from https://doi.org/10.3238/arztebl.2011.0678
  6. National Institute of Diabetes and Digestive and Kidney Diseases. (Reviewed 2021).Binge Eating Disorder.NIH NIDDK. Retrieved from https://www.niddk.nih.gov/health-information/weight-management/binge-eating-disorder/definition-facts
  7. Rumination Syndrome. (n.d). John Hopkins Medicine. Retrieved from https://www.hopkinsmedicine.org/health/conditions-and-diseases/rumination-syndrome
  8. Raha, B., Sarma, S., Thilakan, P., & Punnoose, Z. M. (2017). Rumination Disorder: An Unexplained Case of Recurrent Vomiting. Indian Journal of Psychological Medicine39(3), 361–363. Retrieved from https://doi.org/10.4103/0253-7176.207323
  9. Zimmerman, J., & Fisher, M. (2017). Avoidant/Restrictive Food Intake Disorder (ARFID). Current Problems in Pediatric and Adolescent Health Care, 47(4), 95-103. Retrieved from https://doi.org/10.1016/j.cppeds.2017.02.005
  10. Al Nasser, Y., Muco, E., & Alsaad, A.J. (2022). Pica. In StatPearls[Internet].Treasure Island, FL: StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK532242/
  11. Kar, S. K., Kamboj, A., & Kumar, R. (2015). Pica and Psychosis - Clinical Attributes and Correlations: A Case Report. Journal of Family Medicine and Primary Care4(1), 149–150. Retrieved from https://doi.org/10.4103/2249-4863.152277
  12. Himmerich, H., Bentley, J., Kan, C., & Treasure, J. (2019). Genetic Risk Factors for Eating Disorders: An Update and Insights into Pathophysiology. Therapeutic Advances in Psychopharmacology9, 2045125318814734. Retrieved from https://doi.org/10.1177/2045125318814734
  13. Gander, M., Sevecke, K., & Buchheim, A. (2018). Disorder-Specific Attachment Characteristics and Experiences of Childhood Abuse and Neglect in Adolescents with Anorexia Nervosa and a Major Depressive Episode. Clinical Psychology & Psychotherapy25(6), 894–906. Retrieved from https://doi.org/10.1002/cpp.2324
  14. Kass, A. E., Kolko, R. P., & Wilfley, D. E. (2013). Psychological Treatments for Eating Disorders. Current Opinion in Psychiatry26(6), 549–555. Retrieved from https://doi.org/10.1097/YCO.0b013e328365a30e
  15. Reiter, C. S., & Graves, L. (2010). Nutrition Therapy for Eating Disorders. Nutrition in Clinical Practice: Official Publication of the American Society for Parenteral and Enteral Nutrition25(2), 122–136. Retrieved from https://doi.org/10.1177/0884533610361606