The Genetic Link of Eating Disorders

Is it nature vs. nurture, or both?


Many people don’t realize that eating disorders aren’t a choice. They are highly inheritable – as inheritable as bipolar disorder and schizophrenia. In fact, 40-50 percent of the risk of developing one is genetic. Individuals who have had a family member with the condition are 7 to 12 times more likely to develop it, according to the Center for Eating Disorders.

Just as with other diseases, including mental illnesses, a certain situation can trigger someone’s genetic predisposition to developing an ED. There are also non-biological triggers, such as stress, trauma, an extreme diet, or societal pressure, at play.

Environment and Stress


“The environmental component can vary but the underlying common denominator is the perception of stress,” Dr. Ovidio Bermudez, Eating Recovery Center Chief Clinical Officer and Medical Director of Child and Adolescent Services, says. “Whether the stress is in a social, academic, competitive or a romantic context,” he adds, how a person handles it matters the most.

No Test


No specific genetic defect has been identified in people suffering from the condition, which means there is no specific test to calculate an individual’s risk, Dr. Bermudez says.

“But we know that families can pass on the propensity to develop an ED,” he adds. For example, a woman with a mother or sister who has anorexia nervosa is 12 times more likely than the general population to develop anorexia and four times more likely to develop bulimia nervosa.

Personal Characteristics


Certain personal characteristics can be correlated with a risk factor, he adds. They include perfectionism, high achievement and harm avoidance. If a parent notices these in a child, he or she should be careful regardless of whether there is family history of ED, Dr. Bermudez says.

Manage the Risk


Sports that involve judges, such as gymnastics, maybe should also be avoided, he adds. “Baseball and softball, for example, are less risky.”

Other ways to manage or prevent the risk of developing an eating disorder is not criticizing a person for their weight or appearance and not strictly following diets, unless it’s medically recommended. “A kid sees all that and thinks it’s normal because their parents are doing it.”

“If you need to be on a diet, do it in a thoughtful way that promotes self-acceptance,” Dr. Bermudez says. “It’s all about fostering acceptance and self-esteem,” he adds.



Twins share the same vulnerability, but to a different extent. Among identical twins (with 100 percent the same genetic makeup), there is almost a 60 percent chance that if one twin has anorexia, the other twin will also develop an eating disorder.

Among fraternal twins (with 50 percent the same genetic makeup) there more than a 10 percent chance that if one twin has anorexia, the other twin will also develop an eating disorder.



The biggest indicator is change, Dr. Bermudez says. “As kids grow up, they become more mature and become more social,” he adds. But realizing whether the change is normal or crossing the line is not rocket science.

Pay attention to how they think about the same issues, he adds. “Are they moody? Is it normal moodiness or too persistent?”

A lot if children have concerns about their size and shape. “So look for dramatically changed eating habits. Have they become vegan suddenly for no reason?”

The Gender Factor


“This is not fully understood,” Dr. Bermudez says. “It’s not clear whether it’s nature vs. nurture or both.”

In the U.S., 20 million women and 10 million men will suffer from a clinically significant eating disorder at some time in their life, including anorexia nervosa, bulimia nervosa, binge eating disorder, or other specified feeding or eating disorder.

A study of 2,822 students on a large university campus found that the female-to-male ratio of people suffering from an ED was 3 to 1.

However, various studies suggest that risk of mortality for males with ED is higher than it is for females, according to the National Eating Disorders Association (NEDA).

More readings:

The Connection: What to Know About Suicide and Eating Disorders

How is Binge Eating Really Harming You?

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