When is an Eating Disorder Likely to Develop?

Eating disorders are often thought of as conditions that primarily impact young people—and, in particular, young white females. But the truth of the matter is much more nuanced.

Conditions like anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) arise from a complex combination of interlocking factors, including biological and environmental circumstances. As such, eating disorders can—and do—impact all kinds of people, regardless of age, gender, or race.

Still, some patterns have emerged over years of research, which can help predict what age group is most affected by eating disorders, or who may be particularly vulnerable to developing these conditions.

Eating Disorder Statistics

The nature of how eating disorders are documented and researched can make it challenging to find reliable statistics on the subject. There is no national database on eating disorder cases, so numbers are piecemeal and influenced by each study or organization’s particular definitions.

Further, studies themselves are often skewed, focusing only on particular subsets of the population. Eating disorder studies have historically focused exclusively on white females, making it difficult to find information on the experiences of other people with these conditions.

Still, within those confines, some patterns have emerged, with one study combining the numbers to find the average age for onset of certain eating disorders, including:¹

• Anorexia nervosa: 18.9 years, with a plateau at 26 years
• Bulimia nervosa: 19.7 years, with a plateau at 47 years
• Binge eating disorder: 25.4 years, with a plateau at 70+ years

Yet, even these numbers may be deceptive, as most people struggle with disordered eating behaviors and thoughts long before they enter eating disorder treatment. Instead, a better way to determine when eating disorders are most likely to develop may be to examine common causes of these conditions.

Causes of Eating Disorders

Again, eating disorders can develop at any time, in anyone. However, certain factors can increase the likelihood of these conditions developing at specific times and in specific individuals.

Puberty and Adolescence

Puberty is a particularly vulnerable time for eating disorder onset, and the development of other mental health conditions, including depression and anxiety disorders, which may lead to disordered eating as a coping mechanism. In particular, beginning puberty early has been identified as a risk factor for eating disorders and anxiety disorders.^2,3,4,5

Research suggests that the influx of changing hormones and other internal dynamics during puberty is behind this phenomenon. And these changes can bring on the development of eating disorders in several ways.

New negative beliefs or disordered behaviors adopted during this transitive time may more easily become embedded in an adolescent’s developing adult brain, thanks to shifting hormones and other neurological activity. And puberty can also work to trigger or “turn on” specific genes that may make someone more susceptible to developing an eating disorder.^4,6

Environmental Trauma

The experience of trauma also has a substantial relationship to the development of eating disorders.

One study found that nearly a quarter of women with anorexia nervosa and bulimia nervosa also had clinical characteristics of post-traumatic stress disorder (PTSD), with other studies reporting an overlap of eating disorders and previous trauma at anywhere from 37% to 100%.⁷

Sadly, many of the people in these studies specifically reported histories of childhood trauma, with the experience of sexual trauma, in particular, most indicative of developing weight control behaviors or other signs of disordered eating.⁷

Athletic Pursuits

For some athletes, disordered behaviors or thoughts may develop as they become more serious in the pursuit of their sport or maintaining a particular body shape.

One small study found that excessive exercisers scored higher than non-excessive exercisers on the need to be thin, dissatisfaction with their bodies, and perfectionism, as well as obsessive-compulsive disorder (OCD) symptoms.⁶

The fixation on working out can become obsessive to the point of disruption, with someone only finding relief from those thoughts by engaging in compulsive behaviors, such as excessive exercise or extreme dieting.

Additional Eating Disorder Risk Factors

Several other factors can make it more likely for an eating disorder to develop.

Chronic low self-esteem is thought to be a major factor in the development of nearly all eating disorders. Some researchers have designated the condition a “necessary prerequisite” for anyone to adopt disordered eating behaviors.⁹

Bullying is another highly predictive factor for unhelpful thoughts and behaviors around food, eating, and body image. The prevalence of eating disorders is much higher among those who experienced bullying or teasing around their body weight or appearance growing up.¹⁰

Eating disorders also more frequently impact people who have other co-occurring psychiatric disorders. Substance use disorder (SUD) and substance abuse in general have been tied particularly closely to many types of eating disorders. The National Comorbidity Replication survey found that 27% of people with anorexia nervosa, 37% of people with bulimia nervosa, and 23% of people with binge eating disorder had some kind of substance use disorder.^11,12

When Is an Eating Disorder Likely to Develop?

While most people in modern society experience at least some risk factors for developing eating disorders, including bullying or societal pressure to adhere to certain beauty ideals, only around 9% of the population will have an eating disorder in their lifetime.⁸

Translating to roughly 30 million people in the United States, the number is by no means small, but nor does it represent a majority of the population. The difference, then, between those who go on to develop eating disorders and those who don’t is generally the combination of environmental and biological factors.

For example, those with a family history of disordered eating or serious mental illnesses may be born with certain genes that make them more likely to experience certain stress responses.¹³ 

And while every case and person is different, it’s very rare for eating disorders to develop from only environmental or biological factors. Generally, eating disorders are most likely to develop if someone has both a biological predisposition and a triggering experience.

Finding Help for an Eating Disorder

Eating disorders are serious mental health conditions that can be dangerous or even deadly if left untreated. If you or a loved one is struggling with an eating disorder, it’s crucial to find help for the condition.

If you’re unsure where to start, a trusted medical professional is a great option. Therapists, psychiatrists, primary care physicians, and dietitians, among others, are often educated in a number of eating disorders and may be able to recommend disorder-specific treatment or other helpful treatment options and programs.

If you’d rather not discuss this situation face-to-face, there are several mental health and eating disorder hotlines that can help. These services allow callers to remain anonymous while offering information and resources on a number of different eating disorders and treatment options.

Regardless of where you turn for help, the most important thing is to seek it out. Eating disorders may feel impossible to overcome, but recovery is always possible. Taking the time to look for help can be the first step on the journey toward a healthier and happier future.