Patients, parents, family and friends find solace in asking how an eating disorder starts. Often what makes an eating disorder last is more important for treatment than why it started, but figuring out the initial cause does two important things: creates a story that helps someone make sense of their lives and provides underlying clues for therapy.
I have written at length about the number one cause of an eating disorder: dieting and starvation. Taking in significantly less food than one needs for an extended period of time triggers the innate human response to famine. Metabolism slows, organs function efficiently but less effectively, unnecessary body function is sacrificed. If this time persists, brain changes occur which include decreased cognitive function, obsessive focus on food and increased attention to body shape and weight. The number one reason for the skyrocketing incidence of eating disorders in recent decades is widespread sanctioned dieting, especially in children and adolescents.
The second cause for an eating disorder is genetic predisposition. Not all kids and people who diet end up with an eating disorder. In fact, the large majority don't, even if many of them stay focused on food and weight into and through adulthood. A certain percentage of people have an innate response to eating disorder symptoms, largely a strong biological and seemingly chemical response to the eating disorder symptoms. Prolonged starvation, binging or purging can all trigger powerful chemical responses in the brain that are very calming and, for those are predisposed, almost addictive. In addition, the rigid rules and routine of an eating disorder create calm and safety not as an immediate response but as a longterm salve to the uncertainty of daily life. People who combine the trigger of starvation with the powerful biological response to the behaviors are at higher risk for an eating disorder.
The third component of the cause of an eating disorder is emotional. Kids who lack love, warmth and attention feel as if they have found a panacea in an eating disorder. The almost magical trick of having figured out food--whether through prolonged starvation or a method of eating and purging l--and the positive feedback of being thin replace the emotional pain of feeling unloved and worthless. This experience can range from seemingly benign neglect to emotional or physical abuse to traumatic experiences. The severity of the experience tends to correlate to how much the emotional cause contributes to the eating disorder.
These three components of the cause of an eating disorder do not factor in equally. For some the genetic component is the main instigator of the eating disorder and for some a traumatic childhood is. For most though, the eating disorder started because all three potential reasons came together in such a way that led to the person falling into this illness.
Most people find comfort in having an explanation as to why their eating disorder started. This conversation can be hard but it helps push aside the shame associated with the illness and give the person enough agency to continue taking steps in recovery.