What Is the Difference Between Anorexia and Bulimia?


Eating disorders are serious and life-threatening mental disorders that affect around seventy million people globally, according to the National Eating Disorders Association. Whilst the cause of eating disorders is still not known, they can develop from factors like poor self-esteem and body image, as well as social and peer pressure and often co-occur with other mental health disorders. Both males and females can be affected by these factors and can go on to develop an eating disorder, although girls and women are affected by anorexia and bulimia at much higher rates.

Anorexia and bulimia may seem similar, but they are unique eating disorders with separate sets of symptoms and diagnostic criteria, although some things do overlap. If you or someone you love is struggling with disordered eating, it can be difficult to know how to address it. Understanding more about anorexia nervosa and bulimia nervosa – the two most common eating disorders – can help you spot the signs and know the best way to address the problem. Knowing the difference between anorexia and bulimia might help with knowing the best way to support someone you care about who you suspect has an eating disorder.

What Is Anorexia Nervosa?

Anorexia nervosa causes individuals to restrict food, avoid food, or only eat small quantities of specific foods. It is also common for people with anorexia to weigh themselves regularly, keeping track of their weight – often viewing themselves as overweight, even if they are a normal weight or dangerously underweight.

There are two subtypes of anorexia: a “restrictive” subtype and a “binge-purge” subtype. Both are driven by a strong urge for weight loss.

Anorexia Nervosa: Restricting Subtype

The restricting subtype of anorexia nervosa causes people to tightly restrict energy, or calories, through the intake of food and drinks. This may present in addition to excessive exercise that serves as a way to maintain a certain calorific deficit causing often extreme weight loss.

Anorexia Nervosa: Binge-Purge Subtype

The binge-purge subtype is often driven by an obsession with calorific intake and to prevent weight gain, and individuals will often consume more food than they are meant to and feel excessively guilty for over-eating. This is followed by purging or self-induced vomiting, diuretic use, laxative use, or over-exercise. It is common for people to present with a variety of these behaviours, which can increase the danger even further.

Anorexia nervosa can move between subtypes, so it is important for loved ones to be aware of and monitor changes in behaviour.

Atypical Anorexia

Atypical anorexia is a similar and related condition in which the individual meets the diagnostic criteria for anorexia but has maintained an average weight, not becoming underweight despite tight control of energy intake.

Anorexia Signs and Symptoms

  • Intense desire to lose weight
  • Hair that thins, breaks or falls out
  • Extreme weight loss or not meeting expected developmental weight gain
  • Fear of gaining weight
  • Skipping meals
  • Wearing baggy clothes
  • Distorted body image
  • Thin appearance and low body weight
  • Abnormal blood counts
  • Irregular heart rhythms
  • Low blood pressure
  • Fatigue
  • Mood swings
  • Insomnia
  • Dizziness or fainting
  • Intolerance of cold
  • Absence of menstruation
  • Constipation and abdominal pain
  • Yellowish, dry skin
  • Dehydration
  • Eroded teeth from induced vomiting

What Is Bulimia Nervosa?

Bulimia nervosa, also known as bulimia, is a severe eating disorder that can potentially be life-threatening. Those with bulimia binge-eat, often engaging in secretive binge-eating episodes characterised by feeling like they have lost control while eating food in large quantities. Following a binge, individuals may engage in purging behaviours in an attempt to purge themselves of the excess calories to prevent weight gain. Recurrent episodes of these eating behaviours are required for a diagnosis.

Bulimia nervosa is one of the most common eating disorders, affecting an estimated 1-2% of the population. This makes it more common than anorexia nervosa. Individuals with bulimia nervosa often experience feelings of shame and embarrassment, leading them to hide their eating behaviour and delay seeking help.

Bulimia Signs and Symptoms

Common symptoms of bulimia in teens may include:

  • Consuming an excessive amount of food within a short period of time on a regular basis (binge eating)
  • Purging behaviours to avoid weight gain (such as vomiting, laxative use, diet pills, or diuretics)
  • Feeling guilt or shame after binge eating
  • Experiencing fatigue and frequently needing to sleep
  • Distorted body image
  • Obsession with weight gain and body shape
  • Intense fear of weight gain
  • Low self-esteem
  • Feeling a loss of control and over-eating during binge episodes
  • Avoiding certain types of food or entire meals
  • Feeling uncomfortable being around others who are eating or while eating themselves
  • Experiencing a lack of appetite, missing meals, or losing interest in food
  • Fluctuating weight or struggling to maintain a healthy weight
  • Displaying obsessive or inflexible behaviour around food and eating habits
  • Sensitivity to aspects of food, such as temperature or texture
  • Avoiding social situations where food is present
  • Using supplements or appetite suppressants as a substitute for food and nutrition

Not everyone with bulimia will display all of these symptoms, and some may experience different or additional symptoms. It is important to remember that eating disorders can affect people of all different body sizes and shapes, and weight is not always an indicator of the presence of an eating disorder.

What’s the Difference Between Anorexia and Bulimia?

Behavioural and Psychological Characteristics

There are some behavioural, psychological and emotional signs that overlap between anorexia nervosa and bulimia nervosa, in addition to a number of other eating disorders. These include:

  • Covering up in layers of clothing
  • Fear of gaining weight
  • Repeated weighing or measuring the body
  • Frequently looking in the mirror for perceived flaws
  • Obsession with physical appearance
  • Restricting calorie intake to regain control
  • Making excuses for not eating
  • Restricting food intake, or trying to eat only a few certain foods deemed as safe or healthy that are usually low in fat and calories
  • Complaining about being fat or having imperfections on certain body parts
  • A lack of emotion or ‘flat mood’ that appears like a numbing of emotions
  • Social withdrawal
  • Irritability
  • Inability to make rational decisions
  • Insomnia
  • Feeling tearful and emotionally exhausted or overwhelmed
  • Difficulty concentrating due to a lack of energy
  • Low self-esteem and a reduction in confidence
  • Exacerbation of any existing mental health problems such as depression, obsessive-compulsive disorder (OCD), anxiety etc

Bulimia vs. Anorexia: Differences

Although the two eating disorders have similarities, there are key differences.

One difference between anorexia nervosa and bulimia nervosa is that people with anorexia will use extreme diets or restrict their food intake to lose weight. Those with bulimia binge eat and then purge to lose weight. The physical symptoms can also be different between anorexia and bulimia. Although both can cause changes in body weight, missing periods, dizziness and gastrointestinal issues, the physical symptoms of bulimia often include dental problems due to stomach acid affecting the teeth from frequent vomiting.

How Are Eating Disorders Diagnosed?

Eating disorders are generally diagnosed in multiple steps, which help to eliminate the possibility of other conditions and identify any related complications. The diagnostic and statistical manual five (DSM-5) lists the criteria for diagnosing mental health conditions, including both anorexia nervosa and bulimia nervosa.

The first is most often a physical exam; a medical professional will weigh you to determine your body mass index (BMI), although BMI is not always used as a diagnostic tool for eating disorders. A doctor will also look at your past medical history to assess whether your body weight has fluctuated over time. There will also be questions about your eating behaviour, body image and exercise habits, as well as a mental health questionnaire.

A doctor may also do lab tests to rule out other causes of weight loss. 

If the tests reveal no other causes for your symptoms, you will likely be referred to an eating disorder specialist.

Eating Disorder Treatment Options

The treatment options for anorexia nervosa and bulimia nervosa are similar, often including a combination of therapy, medication, nutritional counselling, and medical supervision. If other mental health conditions are present, treatment should also provide support to address these, as they may contribute to unhealthy behaviours.

Risk factors for disordered eating behaviour include trauma, genetics and psychological factors, and treatment will often seek to address these.

Family therapy is a good option for people with both anorexia and bulimia. The two disorders can sometimes be linked to family behaviour and dynamics, and family therapy can help parents to understand their child’s extreme dieting as a disorder. Cognitive behavioural therapy, trauma therapy and interpersonal therapy are all effective for eating disorder treatment.

Eating disorders such as anorexia, bulimia and ARFID can profoundly impact development and physical health. Inpatient treatment can provide the right nutritional support to ensure a return to healthy bodily functioning.

Recovery at The Wave Clinic

At The Wave Clinic, we offer a range of both clinical and alternative therapies to enhance wellness and promote healing from the inside out. We have highly specialised treatment programmes for young people living with anorexia or bulimia, and every member of The Wave’s treatment team is trained in the care and management of eating disorders.

We know that recovering from an eating disorder can be challenging. Treatment at The Wave Clinic is an opportunity to heal, enjoy new friendships, and build a wonderful gap-year portfolio of life experiences.

Fiona - The Wave Clinic

Fiona Yassin is the founder and clinical director at The Wave Clinic. She is a U.K. and International registered Psychotherapist and Accredited Clinical Supervisor (U.K. and UNCG).

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