Both conditions center around a fixation with losing or controlling weight, perpetuated by negative body image and poor self-esteem, and the two also share several negative physical and psychological consequences.
Still, when it comes to anorexia vs. bulimia, the conditions have several key differences.
Anorexia vs. Bulimia: Similarities
Before learning more about the differences between AN and BN, it can be helpful to understand the ways these conditions are similar.
People struggling with BN and AN have many of the same signs and symptoms. A combination of biological, psychological, and social influences contribute to the development of both eating disorders.
Common signs and symptoms of bulimia nervosa and anorexia nervosa include:7,8
- Negative or distorted body image
- Extreme preoccupation with food, eating, nutrition, and dieting
- Intense fear of gaining weight
- Sense of self-worth heavily tied to weight and appearance
- Social isolation or withdrawal
- Avoiding events or social situations that involve food
Additional physical symptoms that often overlap between AN and BN include:7,8
- Frequent mood fluctuations
- Problems concentrating
- Dizziness
- Gastrointestinal issues
- Trouble sleeping
Anorexia nervosa and bulimia nervosa also share many common risk factors, including:9,10
- Family history or close relative with an eating disorder
- Certain co-occurring mental disorders, such as anxiety and depression
- Obsessive-compulsive, perfectionistic personality traits
Both conditions must be taken seriously and can have a detrimental effect on a person’s mental and physical health over time. But, as with all eating disorders, the individual dealing with the disorder may have difficulties admitting they have a problem and resist seeking help.
Anorexia vs. Bulimia: Major Differences
The biggest difference between anorexia nervosa and bulimia nervosa is the behaviors related to food and eating that tend to manifest in each.
AN is considered a restrictive eating disorder, involving the severe limitation of food intake as its primary symptom. BN is a disorder that involves cycles of binging and purging. Someone with this condition goes through episodes where they eat large quantities of food, then use methods in an attempt to “purge” the food they consumed during the binge, such as:
- Self-induced vomiting
- Over-exercising
- Fasting
- Taking laxatives
Still, different “types” within each condition can blur the lines between the two. For example, there is binge-purge type anorexia nervosa. On the surface, this condition may resemble BN due to its symptoms of binging and purging. But in binge-purge AN, the primary symptom is still food restriction, with binging and purging only used as subsequent maladaptive coping mechanisms.
The nuances between the conditions can be confusing, but knowing the difference is key when it comes to treatment. (In general, anorexia nervosa is more fatal, coming second only to opioid addiction as the deadliest mental health condition.1) Both disorders are treatable, and recovery is possible, but treatment recommendations vary significantly between AN and BN.
Understanding more about each condition specifically can help further illuminate their differences.
Bulimia According to the DSM-5
The Diagnostic and Statistical Manual of Mental Health Disorders, Fifth Edition (DSM-5) is a comprehensive manual that provides diagnostic criteria for mental health conditions. According to the DSM-5, bulimia nervosa has the following diagnostic criteria.2
A person with bulimia has recurrent episodes of binge eating. Binge eating is a pattern of behavior where a person eats significantly more food in two hours than the average person would in similar circumstances and during that same period.
Binging is also characterized by a loss of a sense of control over how much or what is eaten. Eating when not feeling physically hungry, eating past the point of feeling full, or experiencing a sense of guilt or embarrassment following an episode are also part of the diagnosis.
Compensatory behaviors are behaviors a person engages in to make up for specific actions. In the case of bulimia nervosa, these behaviors are used to compensate for binge eating.
People with bulimia engage in what are called inappropriate compensatory behaviors, which are behaviors that are destructive to overall health. These behaviors can include:
- Self-inducing vomiting
- Misusing laxatives, diuretics, or similar medications
- Fasting
- Excessive exercise
In contrast, appropriate compensatory behaviors include talking to a mental health professional to determine what is causing the disordered eating behaviors and develop a strategy to adopt a healthy relationship with food and eating.
Anorexia According to the DSM-5
The DSM-5’s diagnostic criteria for anorexia nervosa are as follows:2
- Restricted energy intake
- Intense feat of weight gain
- Distorted perception of self
Restricted Energy Intake
The primary symptom of anorexia nervosa is the severe restriction of energy intake, compared to what someone requires for their specific age, gender, health status, and several other factors.
The DSM-5 still relies on body mass index (BMI) measurements to determine the severity of an AN diagnosis. However, BMI is increasingly seen as an incomplete indicator of overall health. This also confuses the fact that it is possible to experience anorexia nervosa while being in a larger body.3
Intense Fear of Weight Gain
An extreme fear of weight gain is a cardinal part of an anorexia nervosa diagnosis, as it is often behind much of the restrictive behavior. The diagnosis also includes frequent and intentional attempts to prevent weight gain.
Distorted Perception of Self
People with anorexia nervosa have a distorted body image. Often, this means they see themselves as larger than they actually are. Connected to this eating disorder symptom is an undue significance placed on body weight and shape, with many people struggling with AN basing their self-value on these factors.
In any case, an extreme, negative self-perception is common, along with low self-esteem. People with AN also often struggle to understand the severity of their condition or fail to recognize the damage their behaviors have on their health.
Anorexia Subtypes
Anorexia can be characterized into one of three subtypes.
Restricting-type anorexia nervosa is the most commonly occurring type of AN. It’s characterized by significant restriction of energy intake but without recurrent binge-eating or purging behavior over the last three months.
Binge-purge-type anorexia is characterized by a person engaging in a recurrent pattern of binge eating and purging within the past three months.4 The same maladaptive coping mechanisms are used in bulimia nervosa, but those with binge-purge type anorexia nervosa still meet the DSM-5 criteria for anorexia nervosa. Severe limitation is the primary symptom of this condition, with binging and purging occurring less frequently.
Atypical anorexia shares identical symptoms with more typical cases of anorexia, but the patient is at what is considered a “normal” or higher weight. It is often mistaken for a less severe eating disorder and misunderstood as a less dangerous attempt at weight loss. However, those views are heavily influenced by prevailing attitudes of fatphobia and weight bias.5
In fact, atypical anorexia is not atypical at all and is far more prevalent than anorexia.6 The condition is also dangerous and, just like AN, requires specific and appropriate care.
How to Find Treatment for Anorexia and Bulimia
Regardless of the different labels we currently have for eating disorders, all are complex mental illnesses with serious medical complications that require professional treatment. They do not go away on their own.
Unfortunately, another shared symptom of anorexia and bulimia is that people with these conditions tend to have a hard time understanding the severity of their behavior. Many of them consider their behaviors to be a good thing, attempt to actively hide the truth of their condition, and deny there’s anything wrong.
The truth is AN, BN, and all eating disorders can have life-threatening consequences, especially if left untreated for too long. Fortunately, all of these conditions are also treatable, and no matter which eating disorder someone is struggling with, recovery is always possible.
Resources
- Edakubo S, Fushimi K. (2020). Mortality and risk assessment for anorexia nervosa in acute-care hospitals: a nationwide administrative database analysis. BMC Psychiatry; 20(19).
- Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). (2013). American Psychiatric Association.
- Garber AK, Cheng J, Accurso EC, Adams SH, Buckelew SM, Kapphahn CJ, Kreiter A, Le Grange D, Machen VI, Moscicki AB, Saffran K, Sy AF, Wilson L, Golden NH. (December 2019). Weight Loss and Illness Severity in Adolescents With Atypical Anorexia Nervosa. Pediatrics; 144(6):e20192339.
- Mustelin L, Silen Y, Raevuori A, Hoek HW, Kaprio J, & Keski-Rahkonin A. (2016). The DSM-5 diagnostic criteria for anorexia nervosa may change its population prevalence and prognostic value. Journal of Psychiatric Research; 77:85-91.
- Meadows A. (2019). Weight stigma and physical health: an unconsidered ‘obesity’ cost: Letter to the Editor: Response to Singh et al. (2018). Is there more to the equation? Weight bias and the costs of obesity. Canadian Journal of Public Health; 110(4):525–526.
- Golden NH. (2022). Atypical Anorexia Nervosa is not atypical at all! Commentary on Walsh et al. The International Journal of Eating Disorders; 56(4):826-827
- Anorexia nervosa. (n.d.). National Eating Disorders Association. Accessed February 2024.
- Bulimia nervosa. (n.d.). National Eating Disorders Association. Accessed February 2024.
- Overview – bulimia. (n.d.). National Health Service. Accessed February 2024.
- Anorexia nervosa – symptoms & causes. (n.d.). Mayo Clinic. Accessed February 2024.