Eating Disorders, Environmental or Biological?

Woman in the mountains

Over 10 million individuals suffer with an eating disorder [1]. Research continually grows and gains insight into the risk factors that contribute to this illness. The reasons, thus far, are multifactorial and reflect a range of biopsychosocial factors, such as genetics, temperament, biology, trauma, coping mechanisms,dieting, and sociocultural.

Understanding Biological Factors in Eating Disorder Development

Genetics have seen recent evidence in studies between twins, in the link between eating disorders and genes. These studies have shown that eating disorders may be hereditary and those individuals who have a family member with an eating disorder, are 7-12 times more likely to develop one as well [1, 3].

Temperament, and eating disorders can be associated with specific personality traits. They can be hereditary and are often seen prior to the eating disorder. These traits include, obsessive thinking, perfectionism, sensitivity to reward and punishment, neuroticism or emotional instability and hypersensitivity, impulsivity, and rigidity [1, 2]. Individuals with AN and BN exhibit personality traits in high levels of stress reactivity, negative emotionality, and harm avoidance. These characteristics have been shown to persist even after recovery from the eating disorder is reached [3].
Semistarvation has shown to trigger obsessive behavior around food, depression, anxiety and neuroticism that can continue the starvation cycle. Imaging studies have also show that those with eating disorders may have altered brain neural pathways and reward and inhibition regions [1]. Trauma can also play a factor in the development of an eating disorder.

Survivors of trauma can experience feelings of shame, guilt, body dissatisfaction, and a feeling of lack of control. Eating disorder behaviors can be a way for individuals to cope and manage feelings. As many as 50% of individuals with an eating disorder also suffer with a trauma [1]. Coping skill deficits can also be a factor in the development of an eating disorder.

Being unable to tolerate negative experiences, unhealthy behaviors such as restricting, purging, or binging can be the response to emotional pain, anxiety, stress or trauma [1]. Often the eating disorder behaviors can provide relief but can lead to further psychological and physical harm.

Environmental Factors that Influence Eating Disorders

The media can also play an important role in the thin-ideal of a perfect body size and shape. It promotes unrealistic and unhealthy ideas of what men, women, and often teens should look like. This can be a huge factor in a person’s development of an eating disorder.

Woman in the rainWith the photoshop of magazine and billboard photos, people are susceptible to believing their body is abnormal, or defective, pushing them towards eating disorder behaviors. In 1988 a researcher documented the response of teens in rural Fiji to the introduction of Western culture and television [1].

The exposure created eating disorders within the culture and preoccupations with shape, weight, negative body image and purging. This illustrated the catastrophic effect social media and media has on humans.

Dieting, is another major factor in the development of eating disorders, especially for tweens and teens. More that $60 billion is spent in the United States alone on diets and weight loss products [1, 4]. Even with a 95% failure rate within the industry, individuals continue to use weight loss products and use extreme, eating disorder-like behavior to lose weight.

For individuals who are predisposed for eating disorders, dieting can be the catalyst for increased behaviors and obsessions. Dieting can also lead to yo-yo cycles of weight loss and weight gain, with weight gain typically being 5-10 lbs higher than previously at [1, 4].

Family Roles in Eating Disorder Recovery

Family roles are also considered in contributing to eating disorder development. As previously stated, family genetics may play a part in secondary family members developing the disease. Environmentally, stressful and chaotic family dynamics may trigger eating disorder development in a susceptible family member, though families do not cause eating disorders to happen.

According to the Academy of Eating Disorders (AED), there is no data to support the idea that eating disorders are caused by a certain type of family dynamic or parenting style [1, 4]. They also state that families can be an integral part in the treatment and recovery process, especially with the use of Family Based Treatment for younger patients.

Twin studies have show that the development of anorexia and bulimia is significantly influenced by additive genetic factors, and family studies have shown consistently that anorexia and bulimia have a higher lifetime prevalence of eating disorders among relatives of eating disorders [2, 3, 4].

A study from the University of Iowa and the University of Texas Southwestern Medical center studied single families where eating disorders were cross generational. The researchers found that identified individuals had two gene mutations that were different from other members, increasing the person’s chances of having an eating disorder of 85% [5].

It is also important to look at the genetic link to the development of eating disorders. There are three types of genetic-environment (G-E) have been identified, which are Passive, Evocative, and Active. Passive G-E correlations occur because children obtain genes from their biological parents, who also create the family environment.

Meaning, that the ones that pass the genes on also mold and influence healthy or unhealthy behaviors and attitudes. Children in these families, are getting a double dose of both genetic and environmental influences [2]. Evocative G-E correlations are evoked by the individual with a genetic predisposition for an eating disorder.

This individual may seek out comments related to eating disorder thoughts or perceptions from family and/or peers. These comments can be negative or positive which can reinforce the individual’s ability to over-value that quality or feature.

Roadway rainingMeaning, a child who is dissatisfied with their body image may repeatedly ask their parents for reassurance on if she looks fat [2]. An Active G-E correlation occurs when an individual with genetic vulnerability to an eating disorder seeks out environments that reinforce emphasis on appearance, such as a sport [2].

In conclusion, when examining possible causes of eating disorders, it is important to consider all factors, including biological and environmental influences. Through the literature review, it is just to say that eating disorders are both biological and environment, both influencing the other.

Community Discussion: Share Your Thoughts Here!

Which do you feel influences eating disorders-biological or environment-and why?

Image of Libby Lyons and familyAbout the Author: Libby Lyons, MSW, LCSW, CEDS is a specialist in the eating disorder field. Libby has been treating eating disorders for 10 years within the St. Louis area, and enjoys working with individuals of all ages.



The opinions and views of our guest contributors are shared to provide a broad perspective of eating disorders. These are not necessarily the views of Eating Disorder Hope, but an effort to offer discussion of various issues by different concerned individuals.

We at Eating Disorder Hope understand that eating disorders result from a combination of environmental and genetic factors. If you or a loved one are suffering from an eating disorder, please know that there is hope for you, and seek immediate professional help.

Last Updated & Reviewed By: Jacquelyn Ekern, MS, LPC on January 3, 2017.
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