Atypical Anorexia

What is atypical anorexia?

It is a common misconception that all people with an eating disorder are very thin and have a significantly low body weight. Eating disorders can actually occur in people who are underweight, overweight, or are considered a ‘healthy’ weight ^[1].

Anorexia nervosa is a common eating disorder that can lead to extreme weight loss and low body weight. One of the diagnostic criteria in The Diagnostic and Statistical Manual of Mental Disorders, 5^th edition (DSM-5) states that for a diagnosis of anorexia, restrictive energy intake has led to a body weight that is significantly lower than what is considered normal ^[2].

However, it is possible for someone who is not under a normal weight to be diagnosed with anorexia if they meet all of the other diagnostic criteria for the condition. This is known as atypical anorexia nervosa and can cause the same symptoms and complications as typical anorexia ^[2][3].

Atypical anorexia may even be more common than typical anorexia but is often misdiagnosed or undiagnosed due to misunderstandings around eating disorders and the false view that someone who is of healthy weight or is overweight cannot have anorexia ^[4].

Symptoms of atypical anorexia

The symptoms of atypical anorexia can vary from person to person but may include ^[1][2]:

Physical symptoms

• Stomach pain or gastrointestinal issues such as constipation and bloating
• Significant weight loss that may take place over a prolonged period
• Fatigue and weakness
• Trouble focusing on professional or academic work
• Feeling cold
• Brittle and dry skin, nails, and hair
• Dental issues, such as decay and discoloration

Behavioral symptoms

• Limiting food consumption
• Avoiding certain foods entirely
• Fear of gaining weight
• Low self-esteem and poor body image
• Consistent desire to lose weight
• Counting calories or recording food intake in a diary
• Eating in secret or refusing to eat with others
• Excessive exercising
• Purging behaviors, such as vomiting or using laxatives
• Changes in mental state, such as depression, anxiety, and suicidal thoughts and behaviors

Causes of atypical anorexia

The precise cause of atypical anorexia is not clear and can be due to several contributing risk factors, which are described in more detail below.

Family history

Most eating disorders have a genetic component, meaning that an individual with a family history of eating disorders is likely to be at an increased risk. Similarly, growing up with a family member who demonstrates disordered eating may also influence the development of these behaviors and beliefs around body image ^[3][5].

Prior weight issues

Studies show that high numbers of people with atypical anorexia have been overweight or obese ^[6]. As such, they may have developed issues with body image dissatisfaction, been exposed to bullying around their weight, or engaged in repeated dieting, all of which can contribute to the development of anorexia and disordered eating ^[7].

Mental health history

Many people with an eating disorder have a history of mental health conditions, such as depression, anxiety, low self-esteem, and poor body image, or personality traits such as perfectionism and rigid thinking and behavior. This indicates that these traits and conditions may contribute to the development of an eating disorder ^[3][5].

Trauma

The risk of eating disorders can be increased by experiences of bullying, abuse, or trauma in childhood ^[5].

Social ideals

Societal norms and ideals, particularly in Western cultures and on social media, can contribute to distorted ideas around appearance and body shape and create stigma around bigger bodies, causing some young people to utilize disordered eating behaviors to attain these ideals ^[5].

Gender

Studies have shown that males are more likely to be diagnosed with atypical anorexia than typical anorexia, while females are more likely to be diagnosed with typical anorexia ^[7].

Although research in this area is limited, there is recent research that suggests that atypical anorexia is more common in gender diverse than cisgender people, and that they may be more likely to develop more severe complications from malnutrition than others with atypical anorexia ^[8]. This highlights the need for further research in this area.

Diagnosing atypical anorexia

Unfortunately, atypical anorexia is often misdiagnosed or missed entirely, due to misconceptions around the way that eating disorders present or the individual not understanding or accepting that they are experiencing symptoms of an eating disorder ^[4].

As such, the symptoms may have been present for some time before a diagnosis is made, potentially causing serious medical issues. In some cases, it is due to these physical health concerns that the individual seeks professional help, and the eating disorder is diagnosed.

To make a diagnosis of atypical anorexia, a doctor will gather information about the individual’s own and family history of mental and physical health, particularly a history of eating disorders and changes in weight, and ask for details of current mental and physical health symptoms.

The doctor will conduct a physical examination, which will likely include taking vital signs, such as blood pressure and heart rate, current weight, and blood tests ^[3].

They will ask questions about patterns, behaviors, and feelings relating to food and eating, body image, self-esteem, and mood, potentially utilizing a questionnaire to gather further information, such as the Eating Disorder Examination Questionnaire ^[6][9].

With the gathered information, the doctor will utilize the diagnostic criteria for anorexia nervosa in the DSM-5, including ^[2]:

• Restricting dietary intake
• Fear of weight gain
• Behaviors to prevent weight gain
• Low self-esteem
• Dissatisfaction with body image

To determine a diagnosis of atypical anorexia, the above criteria will all be met. However, unlike typical anorexia, the individual’s body weight is not significantly lower than is expected for their height and age, although weight loss has occurred ^[2][3].

Complications of atypical anorexia

Atypical anorexia nervosa can cause the same medical complications as typical anorexia, sometimes to a higher severity due to delayed diagnosis and untreated symptoms. It has been found that significant and prolonged weight loss can contribute to the development of serious physical health issues, including ^[3][4][7]:

• Low electrolytes and fluid levels: Low levels of electrolytes, such as magnesium, potassium, and sodium, contribute to impairments in normal bodily and cognitive functioning, dehydration, fatigue, and potential organ failure and death.
• Impaired kidney function: Short periods of significant weight loss especially increase the risk of kidney problems.
• Cardiac issues: Heart rate and blood pressure become reduced with poor calorie and nutritional intake.
• Seizures: The risk of seizures increases with reduced electrolytes and cardiac changes caused by malnutrition.
• Brain changes: Prolonged food restriction can cause changes in grey and white matter, altering brain function.
• Stomach issues: Malnutrition can cause nausea, vomiting, and constipation, while recurrent vomiting can cause gastrointestinal reflux and issues in the esophagus, such as tearing.
• Hormonal abnormalities: Malnutrition can cause reduced estrogen levels and missed periods in females and reduced testosterone in males, potentially leading to osteoporosis (although these issues are more common with typical anorexia than atypical anorexia).
• Blood problems: Malnutrition and low iron, B12, and folate intake can cause issues with blood health, including anemia.
• Changes in mental state: Depression, anxiety, and suicidal ideation become more likely, which is believed to be because of a reduction in serotonin production due to malnutrition.

Treatment for atypical anorexia

Treatment for atypical anorexia may depend on the severity of the condition and any presenting physical health conditions. Initially, treatment will require increasing nutritional intake and electrolyte levels, which may resolve certain medical complications ^[3].

Nutritional rehabilitation will require a multidisciplinary approach, with input from a dietician, a specialist therapist, and a physician, who will work together to provide information and support to the individual and their family ^[4].

As many people with atypical anorexia have a history of being overweight or obese, encouraging and promoting weight gain and nutritional intake can present several challenges and can be distressing for the individual, so it is vital to provide psychological and social support alongside physical rehabilitation ^[3][9].

For example, a young person with atypical anorexia who was bullied at school for being overweight may be afraid of regaining weight due to a fear of reoccurring bullying and trauma. As such, support will be required by professionals, family members, and their school to help them manage these anxieties while recovering from their eating disorder.

Interpersonal and family therapies can help to manage the distress that may be caused by increasing nutritional intake, while providing an understanding of the condition, how to manage the symptoms, and how to cope with any other negative feelings that are associated with their condition ^[3][4].

Inpatient care

If the individual is experiencing severe medical complications or they are presenting as a high risk of suicide, they may require inpatient treatment in hospital to maintain their safety and stabilize their physical health. This medical care will also involve input from a multidisciplinary team who can help to improve the necessary aspects of the individual’s physical and mental well-being ^[4].