Eating disorders are not clinically classified as self-harm, but the two are deeply connected. The formal definition of non-suicidal self-injury (NSSI) explicitly excludes eating disorder behaviors like bingeing, purging, and restricting. They occupy separate diagnostic categories. Yet research consistently shows they share the same psychological drivers, affect the same brain systems, and co-occur at striking rates. For many people, eating disorder behaviors function as a form of self-harm even if the diagnostic manual draws a line between them.
Why They’re Classified Separately
Self-harm, in clinical terms, refers to deliberate injury to one’s own body without suicidal intent: cutting, burning, hitting. Eating disorders are classified as distinct conditions with their own diagnostic criteria centered on disordered relationships with food, weight, and body image. The key reason for the separation is that eating disorders involve complex motivations around body shape, identity, and control that don’t always map neatly onto the intent behind self-injury.
That said, this boundary is blurrier than the categories suggest. Some researchers argue that eating disorder behaviors, particularly purging through self-induced vomiting, constitute painful acts that exist on a continuum of harmful behaviors alongside self-injury. Purging causes real physical damage: electrolyte imbalances, liver enzyme abnormalities, dental erosion. It is, by any plain reading, an act that harms the body. The clinical distinction is useful for diagnosis and treatment planning, but it doesn’t capture how these behaviors feel and function from the inside.
How Often They Overlap
The co-occurrence rates are remarkably high. In a large UK cohort study, 63.7% of 16-year-old females who self-harmed also reported disordered eating, compared to 27.1% of those who did not self-harm. Among males the same age, 32.7% of those who self-harmed had disordered eating versus just 6.1% of those who didn’t. These gaps persisted into adulthood: at age 24, 60.9% of women with a history of self-harm reported disordered eating, and 41.9% of men did.
The specific eating behaviors most closely linked to self-harm varied by age and sex. Among 16-year-old girls, fasting was the most common disordered eating behavior in those who self-harmed (47.2%), and purging was associated with the highest rates of self-harm (45.4% of those who purged also self-harmed). At 24, binge eating became the most prevalent co-occurring behavior in women (38.4%). For young men, the patterns were similar but at lower overall rates, with fasting most common at 16 and binge eating most common at 24.
Research also suggests a gateway effect between the two. Engaging in one type of harmful bodily act, whether self-injury or purging, increases the likelihood of engaging in the other. The explanation is that tolerating one form of pain to the body builds a capacity to tolerate other forms, lowering the barrier to additional self-damaging behaviors.
They Serve the Same Psychological Functions
When researchers ask people why they engage in eating disorder behaviors, the answers sound nearly identical to what people say about self-harm. The most commonly reported function, identified across 82 of 144 qualitative studies in one systematic review, is managing emotional distress. People describe eating disorders as a “distress management tool,” a way to replace emotional pain with something physical, or a mental occupation so consuming it blocks out everything else. As one participant put it: “I wanted the physical pain as opposed to the emotional because that made sense.”
The second most common function is a sense of personal mastery and control, reported in 77 of those studies. Restricting food intake, for many, feels like controlling at least one part of a chaotic life. Others described validation: proving to themselves they weren’t weak, that they could endure something difficult. Still others used eating disorder behaviors to communicate distress to people around them when they couldn’t find words for it. One person described it as “my way of talking to the world. It tells everyone what I can’t.”
These functions, regulating emotions, communicating pain, asserting control, seeking validation, are the same reasons people give for cutting, burning, or other forms of self-injury. Research on people who engage in both restrictive eating and self-harm has found that those with co-occurring behaviors have significantly greater difficulty accessing effective emotion regulation strategies when distressed, compared to people who engage in only one of the behaviors. In other words, the overlap tends to be worst in people whose emotional coping resources are most depleted.
Shared Brain Chemistry
The connection isn’t only psychological. Both eating disorders and self-harm involve disruptions in the same brain systems, particularly the body’s natural opioid system and its reward circuitry. When you experience stress or pain, your brain releases chemicals called beta-endorphins that create a brief sense of relief or even euphoria while dampening pain perception. Self-injury triggers this release, and so do certain eating disorder behaviors, especially binge eating.
Both conditions also involve altered functioning in the brain’s dopamine system, which governs motivation and reward processing. The opioid system and dopamine system are closely linked: natural opioids modulate dopamine pathways, increasing dopamine release in reward-related brain areas. This creates a reinforcement loop where the harmful behavior produces a neurochemical reward, making it more likely to be repeated. Serotonin, which helps regulate mood and impulsivity, also shows abnormal patterns in both conditions.
This shared neurobiology helps explain why the two behaviors so often travel together and why one can substitute for or escalate into the other.
The Danger of Co-Occurrence
When eating disorders and self-harm co-occur, the clinical picture becomes significantly more complex and more dangerous. A 2024 study published in The Lancet Psychiatry found that patients with eating disorders who sought mental health treatment were 2.3 times more likely to have a history of self-harm compared to patients with other psychiatric diagnoses. They also had higher rates of additional mental health conditions, longer durations of illness, and were twice as likely to die by overdose.
This elevated risk is one reason clinicians increasingly recognize that treating an eating disorder without addressing co-occurring self-harm, or vice versa, often fails. The behaviors reinforce each other. If you remove one coping mechanism without addressing the underlying emotional dysregulation, the other tends to intensify.
How Treatment Addresses Both
Because the two behaviors serve similar functions, treatment approaches that target emotional regulation tend to help with both simultaneously. Dialectical Behavior Therapy, originally developed for self-harm and suicidal behavior, has been adapted specifically for eating disorders. In specialized programs, patients track both sets of behaviors on daily diary cards: self-harm, suicidal thoughts, restriction, binge eating, purging, and compulsive exercise are all monitored together rather than treated as separate problems.
These programs typically prioritize targets in a specific order: staying alive first, then addressing behaviors that interfere with treatment, then tackling behaviors that interfere with quality of life. The core skills taught, including distress tolerance, emotional awareness, and interpersonal effectiveness, directly address the shared drivers behind both eating disorders and self-harm. Treatment often involves a commitment of at least a year, reflecting how deeply these patterns are embedded.
A particular challenge in treating co-occurring behaviors is that people sometimes shift from one to the other as they recover. Someone working on stopping self-injury may increase restrictive eating, or someone in eating disorder recovery may begin self-harming. Effective treatment anticipates this substitution pattern and builds skills to interrupt the cycle at its emotional root rather than just targeting individual behaviors.