Anorexia nervosa is a complex eating disorder that arises from a combination of multiple factors rather than a single cause. At its core, it involves an intense fear of gaining weight, a distorted body image, and severe restriction of food intake, often leading to dangerously low body weight. Understanding what causes anorexia nervosa requires looking at biological, psychological, social, and environmental influences that interact in unique ways for each individual.
Biologically, genetics play a significant role. People with a family history of eating disorders or certain mental health conditions are more vulnerable. Researchers have found that specific genetic variations can increase the risk, and brain imaging studies reveal differences in brain activity related to hunger, reward, and decision-making in those with anorexia. These biological factors can affect how the brain regulates appetite, satiety, and emotional responses to food, making some individuals more susceptible to developing disordered eating patterns.
Neuroendocrine factors also contribute. Hormones and peptides that communicate between the gut, brain, and fat tissue—such as ghrelin, leptin, neuropeptide Y, and orexin—can become dysregulated. This disruption can interfere with normal hunger signals and feelings of fullness, complicating the body’s natural cues to eat. Additionally, complications during pregnancy or birth, like preterm birth or maternal health issues, may influence personality traits such as harm avoidance, which are linked to anorexia.
Psychologically, anorexia often develops as a coping mechanism. Many individuals use food restriction to gain a sense of control in their lives, especially when facing overwhelming emotions, trauma, or stress. Childhood trauma, including neglect, abuse, or loss, is strongly associated with later development of eating disorders. The disorder can serve as a way to disconnect from painful feelings, regain control, or avoid attention to the body. Mental health conditions like anxiety, depression, obsessive-compulsive disorder, and post-traumatic stress disorder frequently co-occur with anorexia, further complicating its development.
Social and cultural pressures are powerful contributors. Adolescence is a particularly vulnerable time because of hormonal changes, increased body fat, and social expectations for independence. Peer influence, societal ideals of thinness, media portrayals of beauty, and the rise of social media amplify body dissatisfaction and dieting behaviors. For some, the pressure to conform to certain body standards can trigger restrictive eating. This is true across genders, ages, and ethnicities, though certain groups, such as gay and bisexual males, may face additional pressures related to body image within their communities.
Environmental factors also matter. Gastrointestinal diseases like celiac disease can increase the risk of eating disorders due to food aversions and anxiety about contamination. Stressful life events, including trauma reminders or critical comments about appearance, can act as triggers. The interaction between genetic predisposition and environmental stressors often determines the onset and severity of anorexia.
In summary, anorexia nervosa emerges from a complex interplay of genetic vulnerability, brain and hormonal dysregulation, psychological coping strategies often linked to trauma, and powerful social and cultural influences. Each person’s experience is unique, shaped by how these factors combine and interact over time. This multifaceted origin explains why anorexia is so challenging to understand and treat, requiring comprehensive approaches that address biological, emotional, and social dimensions.
