What is Anorexia Nervosa?
By Kelsey Chadwick, MS RDN
Monday February 26, 2024
For National Eating Disorder Awareness Week 2024, we are sharing information about the types of eating disorders. We hope this can serve as a resource for folks looking to learn more about the distinctions between different disorder types.
Anorexia Nervosa (AN) is diagnosed when an individual persistently restricts caloric intake—which can lead to significant weight loss or to arrested growth in children or adolescents. In addition, individuals often experience an intense fear of gaining weight or becoming fat, develop distortions in the way they perceive their bodies and may deny the severity of their behaviors and risks of low weight. Self-worth can become influenced by body size and shape.
Anorexia affects people of all ages, genders, sexual orientation, races and ethnicities. There are two subtypes of anorexia—restricting and binge eating/purging. Restricting type is when an individual is engaging in behaviors like calorie restriction and compulsive over-exercise. Someone with the binge eating/purging subtype may or may not engage in binge eating, but eating of any kind is frequently followed by compensatory behaviors such as vomiting, laxative abuse or diuretic abuse. They may also engage in compulsive over-exercise and may experience significant weight loss.
Diagnostic criteria according to the DSM-5 TR, the following criteria must be met:
Restriction of energy intake relative to requirements leading to a significantly low body weight in context of age, sex, developmental trajectory and physical health
Intense fear of gaining weight or becoming fat, even though underweight
Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation or denial of the seriousness of the current low body weight
Atypical Anorexia, falls under the DSM-5 heading of other specified feeding and eating disorders (OSFED), patients engage in all the same behaviors and have equally severe body image distortions and fears as those with anorexia nervosa, but they are not formally underweight.
The following are behavioral and physical signs of anorexia nervosa:
Behavioral Signs
Dramatic weight loss
Dressing in layers to hide weight loss or stay warm
Preoccupied with weight, food, calories and dieting
Has disturbed experience of body weight or shape or denial of the seriousness of low body weight
Refuses to eat certain foods and often eliminates whole food groups
Denies feeling hungry
Food rituals
Experiences constipation, abdominal pain, cold intolerance and lethargy
Has limited social spontaneity
Maintains an excessive, rigid exercise regimen, despite weather, fatigue, illness or injury
Physical Signs
Stomach cramps and other non-specific gastrointestinal symptoms
Dizziness
Fainting/syncope
Feeling cold all the time
Menstrual irregularities, primary or secondary amenorrhea
Dental problems due to purging
Abnormal laboratory findings (anemia, slow heart rate, low potassium)
Dry and brittle nails
Fine hair on body (lanugo)
Thinning hair
Anorexia nervosa treatment involves working with a team of health and mental health providers that have expertise in eating disorders. A treatment team often includes a physician, psychiatrist, psychotherapist, dietitian and psychiatric nurse. There are varying levels of care and can include outpatient treatment, intensive outpatient specialty eating disorder programs (IOP), partial hospital specialty eating disorder programs (PHP) , residential specialty eating disorder programs and inpatient specialty eating disorder programs.
Additional Statistics
In general, anorexia nervosa has a prevalence of around 1%, with a ratio of females to males of 10:1.1
A meta analysis found that atypical anorexia nervosa (AAN) occurs more frequently than anorexia nervosa in community samples, however fewer individuals with AAN are referred or admitted to special care for eating disorders.2
Sick Enough
Harrop, E. N., Mensinger, J. L., Moore, M., & Lindhorst, T. (2021). Restrictive eating disorders in higher weight persons: A systematic review of atypical anorexia nervosa prevalence and consecutive admission literature. International Journal of Eating Disorders, 54(8), 1328–1357. https://doi.org/10.1002/eat.23519