Environment?  Heredity?  Much discussion and debate has taken place on the subject, and there is no clear cut answer as to how genetics and biology may play into the development of an eating disorder.


There are many things that may play a role in the onset of an eating disorder: family environment, the way a person was taught (or not taught) to cope with their emotions and difficult situations, how they communicate, their self-esteem, and any complicating issues of physical, emotional or sexual abuse.  Another factor can be a history of addiction to drugs or alcohol in a family.  Exposure to pop culture media and advertising can contribute, too, although this is not the be-all-end-all blame factor it was previously thought to be.

The subject of genetics and biology as they relate to eating disorders is something that has been studied more often in the past several years than previously, although the results are often inconclusive or debated by many.  Many people believe that an eating disorder doesn’t really have anything to do with genetics or biology, while others subscribe to the theory that genetics may “load the gun”, but it takes a person’s environment to “pull the trigger”.  Still others, often those with younger loved ones who have anorexia, believe that an eating disorder is more like a disease, and genetics are a big or majority part of developing it, rather than environment.

Although eating disorders started becoming commonly known over thirty years ago, research is still lacking when it comes to supplying commonly accepted theories and data about how eating disorders develop when genetics are factored in.  Often a study that is done may provide possible answers for one group but does not or cannot cover the entire eating disordered population.  One study might produce certain results but the group they studied only had anorexia (the most commonly studied eating disorder), and not any of the other eating disorders, like bulimia, binge eating disorder or EDNOS (eating disorder not otherwise specified).  Some studies only use a certain age group, only use people who have been to an inpatient or residential program, or only study women.  This can make it difficult when trying to apply what is learned from the studies to the varying groups and identifying factors of people with all of the different eating disorders

Below are some results from studies about genetics and eating disorders:

  • The September 2013 issue of the Journal of Studies on Alcohol & Drugs reports that some of the genes that influence alcohol dependence may also influence certain eating disorder symptoms in men and women.  The Washington University School of Medicine in St. Louis conducted the survey, and the results suggest that the range of risk level is 38-53%.  One of the researchers observed that people with eating disorders often experience alcohol and/or drug addiction, too.  On the one hand, this could point to addiction and eating disorders being passed down genetically within families.  On the other hand, it may be that the person who eventually develops an eating disorder has had a difficult environment (parent, sibling or other family member who has an eating disorder and/or is an addict), and that is what contributed to their own eating disorder.  The results do not necessarily allow for genetics and environment having worked in tandem.

  • Craig Johnson, Ph.D., said of a study he co-conducted, “I don't think any of us feel that we're going to find a single gene that will account for anorexia nervosa and bulimia, such as with the gene for Huntington's disease.   We're convinced that instead there will be a number of genes that, to small effect, line up to create susceptibility."

  • Dr. Michael Strober said of such research, “The long-term goal is to identify those aspects of brain-related function that influence development, behavior, and personality, and help us refine the search for potentially more effective pharmacotherapies."  Medication can help in the treatment of eating disorders, particularly when other conditions are in play (such as depression or anxiety), but there is no medication that will “cure” an eating disorder.  Strober goes on to say, “More effective new medications will be important, but a combination of approaches is essential. The importance of psychotherapy should never be minimized."

  • Cinnamon Bloss, Ph.D., is hopeful that studies can find ways to create “treatment based on the person’s genetic makeup, with the goal of more personalized and effective treatments.”  She acknowledges biology and genetics are meaningful, as well as environmental and other issues.  “Anorexia and bulimia likely stem from many different causes, such as culture, family, life changes and personality traits.  But we know biology and genetics are highly relevant in terms of cause.” 

Studies have shown that if a person’s mother or sister has anorexia, that person is much more likely to develop anorexia.  What isn’t fully understood or agreed upon is that this could point to genetics a great deal, but it could also point to environment, or both.  A child who is raised by a woman who is anorexic and sees the behaviors (restricting food, calorie counting, negative body image, no healthy coping skills) is much more likely to mirror what she knows than someone who has a mother who is not anorexic.  As well, a person, regardless of genetic predisposition, who lives with a sibling that has anorexia not only also sees those same things happening, but may relate their sibling’s eating disorder to a way to get attention or not have to do or accomplish the same things expected of a child without an eating disorder.  Sometimes a sibling of a child with an eating disorder who has watched their ill sibling receive a lot of time, money and attention from their parents and others will end up acting in similar ways, including developing an eating disorder as a way to cope with the family discord or receive similar attention.