Key Takeaways
- Eating disorders often come from a mix of biological, psychological, social, and environmental factors.
- Risk factors for eating disorders can include trauma, low self-esteem, and body image issues.
- Families with high levels of rigidity might increase the risk for eating disorders.
When a person gets sick, it’s natural to want to understand why. With eating disorders, which are associated with many myths and negative stereotypes, the question of causation can be incredibly confusing.
The culture at large commonly blames eating disorders on oversimplified explanations, such as the media’s promotion of unrealistically slender models or bad parenting. Even some health professionals buy into these overly simplistic explanations.
This article explores some of the risk factors that may increase the likelihood that a person might develop an eating disorder, including the impact of both environmental and genetic variables. It also discusses the potential causes of specific eating disorders, such as binge eating disorder, anorexia nervosa, bulimia nervosa, and purging disorder.
Watch Now: Common Signs of an Eating Disorder
Risk Factors for Eating Disorders
Many factors have been, or are being, studied as possible contributors to the development of eating disorders. Across all types of eating disorders, it is likely that mental health and body image-related factors play a significant role in causing eating disorders.
Mental Health
Mental health risk factors can include anxiety, depression, low self-esteem, and trauma such as childhood sexual abuse. Social stressors, such as peer pressure and bullying, may also be involved.
Body Image
Risk factors related to eating behaviors and body image may also be tied to the development of eating disorders. These could include:
- Teasing and critical comments about weight
- Body dissatisfaction
- Having a fixation with a thin body
Family Dynamics
Family dysfunction has long been cited as a cause of eating disorders. However, families don’t cause eating disorders in a simple, straightforward manner.
While growing up in a dysfunctional home could increase the risk for many psychological problems, including eating disorders, it does not condemn a child to an eating disorder or any other psychological disorder.
Some research suggests that family functioning characterized by high levels of rigidity may be associated with a higher risk of disordered eating behavior.
Other Factors
Early childhood feeding, eating, or gastrointestinal problems can also contribute to the development of eating disorders.
Recap
Scientists can’t say exactly what causes an eating disorder or predict who will develop an eating disorder. There are many different pathways to the development of an eating disorder.
Risk Factors for Specific Eating Disorders
Risk factor research focuses on identifying traits or experiences that precede the development of a specific eating disorder (not just the overall category of eating disorders). For a risk factor to be shown as a causal factor, the risk factor must come before the development of the eating disorder.
The risk factor(s) must also be capable of being manipulated to prevent the occurrence of the disorder. For example, smoking is a causal risk factor for lung cancer; it comes before the development of the disease, and not smoking reduces one’s risk of developing lung cancer.
Because eating disorders are relatively rare and diverse disorders, it is difficult and expensive to perform the large and long-term studies needed to better assess risk factors.
To date, there is limited research that has successfully demonstrated causality; however, a 2016 study found the following causal risk factors for specific eating disorders:
Anorexia Nervosa
People with anorexia nervosa restrict their food intake, have an intense fear of weight gain, and have a distorted perception of their weight and health. A low body mass index (BMI)—essentially, underweight—has been identified as a risk factor. However, anorexia nervosa can still happen in people with a BMI in the normal range.
Problems With BMI
Body mass index (BMI) is a dated, biased measure that doesn’t account for several factors, such as body composition, ethnicity, race, gender, and age. Despite being a flawed measure, BMI is widely used today in the medical community because it is an inexpensive and quick method for analyzing potential health status and outcomes.
Bulimia Nervosa
Bulimia nervosa, characterized by repeated episodes of binge eating and purging, has several identified risk factors. These include:
- Believing that thinness is equivalent to attractiveness (thin-ideal internalization)
- Having a negative body image (body dissatisfaction)
- Perceiving external pressure to be thin
- Dieting frequently
- Taking weight loss supplements
Binge Eating Disorder
Binge eating disorder is similar to bulimia nervosa but without the purging aspect. This eating disorder was added to the “Diagnostic and Statistical Manual of Mental Disorders” (DSM-5) in 2013.
One study noted that in girls, the following were associated with binge eating in adulthood:
- Body dissatisfaction in adolescence
- Depressive symptoms
- Low self-esteem
A 2017 study suggested that negative urgency, described as a “tendency to act impulsively when distressed,” is also involved.
Purging Disorder
Purging disorder is similar to bulimia nervosa, but in this case, the behavior is limited to purging without binge eating. The only causal risk factor identified by the 2016 research is dieting. Other research has suggested that risk factors for purging disorder are similar to those for bulimia nervosa and binge eating.
Identifying actual causal factors for a specific eating disorder is complicated. Determining whether these factors are present in an individual can be difficult. Also, the presence of these factors predicts higher risk but does not guarantee the development of an eating disorder.
Genetic Factors
Coming from a family with a history of eating disorders can increase a person’s risk of developing an eating disorder. A portion of this increased risk could be due to the modeling of eating disorder-linked behaviors within a family (e.g., observing a family member dieting).
However, twin study research, which can isolate the role of genetics, suggests that approximately 40% to 60% of the risk for anorexia nervosa, bulimia nervosa, and binge eating disorder arises from genetic influence.
Latest Research
The largest and most rigorous genetic investigation of eating disorders ever conducted, the Anorexia Nervosa Genetics Initiative (ANGI), is currently underway in the United States, Sweden, Australia, the United Kingdom, and Denmark. This research could provide more information about the genetic profile that contributes to eating disorders.
These findings do not imply that there is a single eating disorder gene or even that genes cause eating disorders. Some individuals may inherit traits such as anxiety, fear, perfectionism, or moodiness that have been associated with the development of an eating disorder. These aspects of temperament have also been linked to several other disorders.
For some people, variations in several different genes contribute to traits that, in turn, increase or decrease their risk for eating disorders.
Prevalence in Families
Some people with eating disorders are able to identify several other family members who also have eating disorders. There are certain families in which the risk of eating disorders is much higher than in the general population, but such families are relatively rare.
Even a high-risk family history indicating an increased genetic risk does not mean a person is destined to develop an eating disorder. Conversely, not everyone with an eating disorder can identify another family member with one.
Most eating disorder cases are sporadic, with no family history. Given the smaller size of today’s families, there is often not enough data to determine whether a specific individual has a genetic tendency.
Eating disorders are stigmatized diseases, and family members often do not share their struggles with their disorder.
Environmental Factors
Much of the earlier research on eating disorders examined environmental risk factors. As a result, they are frequently blamed for causing eating disorders. Environmental factors include events and influences in an individual’s life, such as:
Influences such as gender, ethnicity, or certain athletic settings can strengthen or lessen other environmental factors.
The tripartite model is one model for understanding some of the socio-cultural risk factors for eating disorders. It proposes that exposure to media, peer, and parental messages all contribute to whether a person idealizes thinness and engages in social comparison. Idealization and social comparison may lead to poor body image and various forms of disordered eating.
Recap
Society and culture influence eating behavior, as well as our concept of ideal body shape. However, such environmental factors cannot fully account for the presence of eating disorders. If they did, 100% of the people exposed to the environmental factor(s) would develop an eating disorder, which we know is not the case.
Protective Environmental Factors
Some environmental factors could help protect people from developing eating disorders. These could include:
Techniques that help groups and individuals question and challenge unrealistic beauty ideals (including the glorification of thinness and the stigmatization of overweight people) are also helpful and protective. People are starting to practice body positivity and neutrality.
Social and environmental changes, such as improving the status and power of women, reducing the objectification of both men and women, and increasing respect for people of all sizes and shapes, will benefit everyone, not just those at risk for eating disorders.
These changes help create kinder, safer, and likely more protective communities.
Gene and Environment Interplay
Neither genes (nature) nor environment (nurture) cause eating disorders independently. Eating disorders are likely the result of a complicated interplay of these factors.
Even when a precipitating factor (such as a traumatic event) can be identified, there is almost always a combination of other contributing factors that play a role. The precipitating factor is most likely the trigger that knocked over the first domino and tripped a cascade of events.
Genetic susceptibility may influence their response to specific stressors. For example:
- A person genetically susceptible to an eating disorder may be more sensitive to weight-related teasing and have a heightened reaction to it (for instance, initiating a diet that snowballs into a disorder).
- A person who is genetically vulnerable may continue dieting much longer than peers who diet and then stop.
- A person with the temperament that commonly underlies anorexia nervosa (anxious and perfectionistic) may seek out the types of social environments that contribute to the onset of dieting.
Epigenetics
The emerging field of epigenetics, the study of whether, how, and when genes are expressed, offers further insight. Epigenetics explains that certain environmental factors determine the expression of genes or even turn specific genes on or off in the next generation.
The stress that parents experience alters their behavior and can turn genes on and off in offspring who were not even exposed to that stressor.
In terms of eating disorders, there is evidence that the longer a person has anorexia nervosa, the greater the chance they will have alterations in how their genes are expressed. It appears that malnourishment could turn on or off certain genes, which influence the course of the disorder. However, epigenetic studies of eating disorders are in their infancy.
Eating Disorders Are Complex
Just as environmental factors can increase a person’s susceptibility to an eating disorder, the converse is also true: Changing the environment can facilitate prevention and recovery. For example, growing up with warm, nurturing parents could mitigate genes predisposing someone to anxiety. However, chance and luck also play a role, and individuals vary in their genetic risk.
Even in the face of every preventative measure, some people with extremely high genetic risks may still go on to develop an eating disorder after just one or two triggering events that are outside of their control. Others with low genetic risk may show resilience to developing an eating disorder even in the face of many potential environmental risk factors.
When someone develops an eating disorder, it’s no one’s fault. The cause of eating disorders is too complex to attribute blame to any one person, event, or gene.
