Anorexia and bulimia are considered the two “sisters” of eating disorders. Eating disorders are pathologies characterized by alterations in eating habits and excessive concern about weight, which can significantly impede physical health or psychosocial functioning. Every year, on March 15th, on Lilac Bow Day, the importance of promoting the spread of adequate treatments for these disorders is remembered.
Characteristics of anorexia and bulimia
Although they are two separate and distinct disorders, anorexia and bulimia they can be considered variations of a single disorder, due to the overlap of clinical characteristics and symptoms and the frequent oscillation from one disorder to another.
Major diagnostic manuals describe anorexia and bulimia as:
- separate entities
- with specific diagnostic criteria
- with hypotheses of different causes and mechanisms
- with distinct therapeutic indications.
In clinical reality, however, the division between anorexia, bulimia and eating disorders not otherwise specified is not so defined and these clinical pictures can be interpreted as variations of a single disorderhow two sides of the same coin. Before better understanding why, let’s try to understand what anorexia is and what bulimia is.
Anorexia
The term anorexia literally means “lack of appetite” (from Greek an-òrexis), although hunger is always present in those who suffer from it, even if defensively denied for fear of gaining weight.
Anorexia nervosa is a psychopathological disorder focused on the more or less pronounced refusal to eat which leads to serious physical and psychological consequences. To achieve the desired weight loss, people with anorexia can implement:
- purging behaviors such as self-induced vomiting and the use of laxatives and diuretics;
- engaging in excessive exercise, dieting and fasting.
The disorder occurs predominantly in young women during adolescence and the male-female ratio is 1:10.
Bulimia
The etymology of the word “bulimia” comes from the Greek terms boùs“ox” e limos“hunger”, that is, “hunger like an ox”, which indicates the appellants binge of people suffering from this disorder, capable of introducing up to 5000 calories in a single meal.
During these binges, food ingestion is:
- voracious;
- compulsive;
- with little attention to flavors.
The food can be of various kinds: sweets, cold or even still frozen dishes. The bulimic orgy, almost always conducted in solitude, generally continues until the person feels so full that he or she feels sick, and it is at that point that purging behaviors begin to prevent weight gain. In other cases, body weight is maintained through exaggerated exercise or fasting phases.
During bulimic bouts, people feel like lose control of oneself to the point of reporting a feeling of estrangement, while afterwards the crises take over sense of guilt And self-devaluation. Like anorexia, bulimia is also prevalent in females with a male-female ratio of 1:20, but with a less early onset, in late adolescence or early adulthood.
Official diagnostic criteria and subtypes according to DSM-5
To fully understand the differences and similarities between anorexia and bulimia, it is useful to refer to the official diagnostic criteria reported in DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, fifth edition)an international reference tool for the diagnosis of mental disorders.
Anorexia nervosa can be diagnosed when:
- Restriction of calorie intake compared to requirement, which leads to a significantly low body weight in relation to age, sex and development.
- Intense fear of gaining weight or to gain weight, even when you are underweight.
- Altered perception of weight or body shapeexcessive influence of weight on self-esteem or failure to recognize the severity of the condition.
The DSM-5 distinguishes two subtypes of anorexia nervosa:
- Restrictive subtype: Weight loss is achieved primarily through dieting, fasting, or excessive exercise.
- Binge/purging subtype: the person regularly binges or engages in purging behaviors such as self-induced vomiting, use of laxatives or diuretics.
Bulimia nervosa can be diagnosed when:
- Recurring episodes of binge eatingcharacterized by the intake of a large amount of food in a limited period and the feeling of loss of control.
- Recurring inappropriate compensatory behaviors to prevent weight gain, such as self-induced vomiting, excessive use of laxatives, fasting, or excessive exercise.
- The episodes must occur at least once a week for three months.
- Self-esteem affected excessively by weight and body shape.
These criteria help professionals to distinguish between different eating disorders and to identify the most suitable therapeutic path.
Two sides of the same coin
Anorexia and bulimia are therefore marked by overlap of clinical characteristics and symptoms. The clinical course of these disorders and their pattern of transmission within families suggest that the two disorders they are not entirely independent, nor entirely overlapping.
Diagnoses of anorexia and bulimia nervosa are often found within the same family, suggesting that these two disorders may share the same causes. An essential and common characteristic of anorexia and bulimia is the presence of an altered perception of body weight and self-image.
Studies and statistics
Some studies show that 30-44% of people with restrictive anorexia vary over time towards forms with binge eating/purging behaviors and that the onset of these behaviors occurs mainly within 5 years. Studies also show a notable fluctuation of symptoms: from anorexia nervosa to bulimia nervosa and vice versa.
The swing rate from anorexia to bulimia (36%) is higher than that from bulimia to anorexia (27%). Eating disorders, therefore, are not stable. The behavioral manifestations of excessive evaluation of weight and body shape change with increasing age and duration of the disorder.
In the early stages, most people manage to maintain the check on eating and losing weight, but over time problems can arise binge eating episodes. The result is the recovery of some or all of the previously lost weight.
Relational methods of those suffering from eating disorders
The food symptomatology, with its alternation of fasting, bulimic crises and emptying practices, reflects the relational methods of those who suffer from it. These people often oscillate between:
- the desire for a poorly differentiated relationship;
- the anxieties of being subsumed by the other, which lead to defensive measures of avoidance and rejection.
The contemporary is often evident intolerance of loneliness and relational closeness: both in fact threaten the integrity of the person’s identity. Refusal of food in some cases takes on the meaning of an assertion of one’s independence aimed at establishing control over oneself. On the contrary, unregulated eating, which in some cases takes the form of an addiction such as food addiction, seems to respond to an attempt at self-medication and fill an emotional void.
Epidemiological data and impact on the population
Eating disorders represent a growing public health challenge, especially among adolescents and young adults. According to theHigher Institute of Health (ISS)in Italy it is estimated that approximately 3 million people suffer from an eating disorder, with a higher prevalence among women (around 90% of cases) than men (Istituto Superiore di Sanità, 2023).
Anorexia nervosa can affect approx 0.3-0.5% of young women and bulimia nervosa approx 1-2% (World Health Organization, 2022). Onset typically occurs between 12 to 25 years oldbut in recent years a lowering of the age of onset has been observed, with cases even in pre-adolescent age (ISS, 2023).
These disorders can have a significant impact on quality of life, physical and psychological health and, in the most serious cases, can be life-threatening. Anorexia nervosa, in particular, is often associated with one of the highest mortality rates among psychiatric disorders (WHO, 2022).
Theoretical models: Fairburn’s transdiagnostic model
To explain the similarities between anorexia and bulimia, several scholars have proposed theoretical models that help understand the shared nature of these disorders. One of the most influential is the Christopher Fairburn’s transdiagnostic modelprofessor of psychiatry and researcher in the field of eating disorders.
According to this model, anorexia and bulimia share a number of basic psychological processes, including:
- Overestimation of weight and body shape: Personal worth is judged primarily by weight and nutrition control.
- Strict controlling behaviors: such as restrictive diets, which can lead to loss of control and binge eating.
- Restriction and compensation cycles: Food restriction can trigger episodes of binge eating, followed by feelings of guilt and compensatory behaviors.
The transdiagnostic model suggests that, despite differences in symptoms, the underlying psychological mechanisms are similar and that an integrated therapeutic approach may be effective in some cases for both disorders (Fairburn, Cognitive Behavior Therapy and Eating Disorders, 2008).
Transitions between anorexia and bulimia: Overview and longitudinal data
Transitions between anorexia and bulimia are clinically relevant and well-documented phenomena. Longitudinal studies have shown that a significant percentage of people with anorexia nervosa can develop bulimic symptoms over time and vice versa.
According to a review published on The American Journal of Psychiatry (Eddy et al., 2008), approximately the 30-50% of people with anorexia nervosa may develop bulimic symptoms throughout life, while the transition from bulimia to anorexia occurs in approximately 10-20% of cases. These data confirm that eating disorders are not static conditions, but can evolve and change shape over time.
Transitions are often influenced by factors such as:
- Duration of the disease: The longer the course, the greater the probability of fluctuations between disorders.
- Psychological and environmental factors: Stress, life changes or traumatic events can favor the transition from one disorder to another.
- Response to treatments: Some people may change their eating behaviors in response to therapy or self-management attempts.
This variability highlights the importance of careful clinical monitoring and a flexible and personalized therapeutic approach.
A tool such as the EAT-26 test, which investigates the symptoms of eating disorders, can be useful to acquire greater awareness of your state of well-being. Always remember to consult a professional for a correct interpretation of the result, as one psychologist who works on issues related to eating disorderseven online.
If you feel the need for support, with Evidence Network you can turn to a psychologist who deals with issues related to anorexia or a psychologist who deals with issues related to bulimia, finding a safe space in which to explore your difficulties and begin a journey of awareness and well-being. Take the first step towards your well-being: Evidence Network is here to accompany you.
