Why do some people develop eating disorders?

Considering eating disorders are so common, you might be curious to know what causes an unhealthy relationship with food. The long and the short answer is both your genetics and societal influences.
“We say that genetics load the gun and environment pulls the trigger,” explains Bonnie Brennan, a senior clinical director at an eating recovery centre. “Genetic predisposition, though not necessary, can play a big part in the risk.”
In fact, a study published in 2017 in the American Journal of Psychiatry shows that in addition to the psychosocial component, biological factors also play an extremely important role in the onset of anorexia nervosa. “More research is needed to determine the prevalence of eating disorders among those of different races and ethnicities, but we do see symptoms of eating disorders across all populations,” says Brennan.
A big life change can evoke an eating disorder

You might not realise you have a predisposition to anorexia or binge eating (especially if your parents never discussed their struggles with you) until something life-altering or impactful happens to you (aka a trigger). “Those at higher risk may also be struggling with other mental health and substance use problems, stressors, or exposure to activities that emphasise size and weight,” says Brennan. “We also see eating disorders develop in response to life stage changes such as puberty, going to college, mid-life challenges, and loss of relationships.”
It’s not just anorexia that’s deadly

Though anorexia tends to get more media coverage, there are several types of what’s known as body dysmorphic disorder (unhealthy relationships with body image). Anorexia is classically defined as someone who severely restricts their kilojoule intake – either by not eating or exercising heavily to burn kilojoules. Bulimia is characterised by a rollercoaster of binge eating, followed by purging – making themselves throw up or have diarrhoea. “Exercise-orexia,” though not an official diagnosis, is the name given to people who exercise compulsively. Orthorexia is a condition of being hyper-focused on eating only the healthiest, cleanest foods. Another less well-known disorder is binge eating, in which you scoff down more than what’s comfortable, with no control over your actions. A review of studies published in 2018 in the journal F1000 Research suggests that antidepressants and various cognitive behavioural therapy modalities are effective treatments in reducing the severity of body dysmorphia, but there are a significant percentage of patients who are treatment-resistant. All of these conditions can be life threatening and dangerous, and they all have similar warning signs.