Eating Disorders and OCD

When people think about eating disorders and obsessive-compulsive disorder (OCD), they often picture them as two very different conditions. On the surface, that makes sense. Eating disorders focus on food, body image, and weight, while OCD focuses on intrusive thoughts and repetitive behaviors. 

But research shows that these two mental health conditions frequently overlap.

This article takes a deep look at the relationship between eating disorders and OCD—what they are, how they overlap, why the comorbidity happens, and what it means for treatment and recovery.

What Are We Talking About? Basic Definitions

What is an eating disorder?

Eating disorders are serious mental health conditions that affect the way people think, feel, and behave around food, eating, body image, and weight. They’re not just “diets gone too far” or about vanity. Instead, they represent a complex interaction of psychological, biological, and social factors that can have life-threatening consequences if untreated (National Institute of Mental Health, 2023).

Eating Disorders Are Not Just About Food

While eating disorders center around eating behaviors, food is rarely the core issue. Instead, food and body image become the focus of deeper emotional struggles, such as anxiety, perfectionism, trauma, or a need for control. For many, restricting, binging, or purging functions as a way to cope with overwhelming thoughts or emotions.

The Main Types of Eating Disorders

Several different eating disorders are recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Each has unique symptoms, but they share patterns of disordered thinking and behavior around food and body image:

  • Anorexia Nervosa (AN):
    Characterized by extreme food restriction, intense fear of gaining weight, and a distorted body image. People with anorexia may see themselves as larger than they are, even when underweight. It has one of the highest mortality rates of any psychiatric illness due to both medical complications (like organ failure, electrolyte imbalance, osteoporosis) and suicide (Arcelus et al., 2011).
  • Bulimia Nervosa (BN):
    Involves cycles of binge eating (eating large amounts of food in a short time, with a sense of loss of control) followed by compensatory behaviors such as vomiting, laxative misuse, fasting, or excessive exercise. This cycle can cause electrolyte imbalances, gastrointestinal issues, and heart complications.
  • Binge-Eating Disorder (BED):
    The most common eating disorder in the U.S., BED is marked by recurrent episodes of binge eating without regular compensatory behaviors. People often eat very quickly, eat past physical fullness, and experience shame or guilt afterward. BED is associated with higher rates of depression and anxiety and affects people of all body sizes.
  • Other Specified Feeding or Eating Disorders (OSFED):
    When symptoms don’t meet the full criteria for AN, BN, or BED, but still cause significant distress and impairment, they fall under OSFED. Despite being less talked about, OSFED is very common and just as serious as other eating disorders.
  • Avoidant/Restrictive Food Intake Disorder (ARFID):
    Often beginning in childhood, ARFID is not about weight or body image but involves extreme restriction due to sensory sensitivities, fear of choking/vomiting, or lack of interest in eating. This can still lead to malnutrition, anxiety, and social difficulties.

Who Can Develop an Eating Disorder?

Eating disorders affect people of all genders, ages, races, and body sizes. Historically, they’ve been stereotyped as affecting only young, thin, white women, but research shows they are just as prevalent in other populations (Strother et al., 2012).

Why Eating Disorders Are Serious

Eating disorders are not lifestyle choices, they’re serious mental illnesses with high risks. In fact, anorexia nervosa has the highest mortality rate of all psychiatric conditions, and all eating disorders carry elevated risks of suicide and medical complications (Ágh et al., 2016). Common health effects include:

  • Malnutrition and nutrient deficiencies
  • Electrolyte imbalances leading to cardiac problems
  • Gastrointestinal complications
    Bone density loss (osteoporosis/osteopenia)
  • Fertility issues
  • Severe psychological distress, including depression, OC, and suicidal thoughts

The Bottom Line

Eating disorders are far more than food issues, they’re multi-layered mental illnesses. They require specialized treatment and support, often involving a team approach (therapy, nutrition, and medical care). 

And because eating disorders and OCD frequently overlap, understanding the nuances of each can be key to proper diagnosis and recovery.

This is only a brief explanation of eating disorders and is not meant to be all encompassing or diagnostic. 

What is OCD (Obsessive-Compulsive Disorder)?

Obsessive-compulsive disorder (OCD) is a chronic mental health condition that affects about 2–3% of the population worldwide (Wu & Carter, 2009). It’s not just about being “neat” or “organized,” which are two common misconceptions. Instead, OCD involves intrusive thoughts (obsessions) and repetitive behaviors or mental rituals (compulsions) that cause distress and interfere with daily functioning.

Obsessions: The “Thought” Side of OCD

Obsessions are intrusive, unwanted, and often distressing thoughts, images, or urges. They feel “sticky,” meaning the person can’t just dismiss them, even if they know the thoughts don’t make sense. Some common obsessions include:

  • Contamination fears (germs, dirt, chemicals, food contamination)
  • Symmetry or exactness obsessions (“things must feel ‘just right’”)
  • Harm obsessions (fear of accidentally hurting others, violent or aggressive intrusive images)
  • Religious or moral obsessions (scrupulosity—fear of sinning, offending God, or being immoral)
  • Sexual or taboo obsessions (unwanted intrusive sexual images or fears of being deviant)

In the context of eating disorders, obsessions might overlap. For example, constant intrusive thoughts about calories, body shape, or contamination of food.

Compulsions: The “Behavior” Side of OCD

Compulsions are the behaviors or mental acts that a person feels driven to perform to reduce anxiety caused by obsessions. While compulsions may provide temporary relief, they actually reinforce the cycle of OCD. Examples include:

  • Cleaning/washing: repeated hand washing, cleaning food items excessively
  • Checking: making sure appliances are off, repeatedly checking nutritional labels
  • Ordering/arranging: lining up objects symmetrically, cutting food into perfect pieces
  • Mental rituals: repeating prayers, counting, or mentally reviewing events
  • Avoidance: staying away from “triggering” situations (like restaurants or shared meals)

When eating disorders and OCD overlap, compulsions may blur. 

For example, someone might wash their food repeatedly because of contamination fears (OCD) or avoid food due to fear of weight gain (ED).

How OCD Works in the Brain

Neurobiological research shows that OCD involves dysfunction in the cortico-striato-thalamo-cortical (CSTC) circuit, a brain loop involved in habit formation, error detection, and decision-making (Pollack et al., 2013). 

Essentially, the brain gets “stuck” in overdrive, sending false alarms that something is wrong. This contributes to the repetitive, hard-to-break nature of compulsions.

OCD Myths and Misunderstandings

Because OCD is often portrayed lightly in media—“I’m so OCD about my desk!”—people don’t always recognize how debilitating it can be. Real OCD is not about quirks or preferences. While they can overlap, OCD is not perfectionism. It can:

  • Take up hours each day
  • Cause significant emotional distress
  • Interfere with work, school, or relationships
  • Lead to shame and secrecy, delaying treatment

OCD and Anxiety

OCD is classified as an anxiety disorder in earlier diagnostic systems, though the DSM-5 now places it in its own category: Obsessive-Compulsive and Related Disorders. 

Still, anxiety is central. Compulsions exist because they provide (temporary) anxiety relief, even though they keep the disorder going long-term (American Psychiatric Association, 2020).

Please note: This is only a brief explanation of OCD and is not meant to be all encompassing or diagnostic. 

Prevalence: How Often Do Eating Disorders and OCD Co-Occur?

Rates of OCD in eating disorder populations

Studies consistently show that OCD is more common in people with eating disorders than in the general population. A large meta-analysis found that 15% of individuals with an eating disorder also have current OCD, and 18% meet criteria at some point in their lives (Mandelli et al., 2020).

Other studies suggest that anorexia nervosa, especially the restrictive subtype, is more likely than bulimia or binge-eating disorder to overlap with OCD (Selles et al., 2022). In some treatment settings, up to 40% of people with anorexia nervosa also meet criteria for OCD.

Rates of eating disorders in OCD populations

Looking at it from the other side, people with OCD are also at increased risk for eating disorders. Estimates suggest that 8–12% of individuals with OCD will also develop an eating disorder (Tyagi et al., 2015). That’s much higher than rates of eating disorders in the general population, which are typically estimated around 1–3%.

Why the rates vary

Prevalence numbers differ depending on the sample studied, diagnostic criteria, and whether researchers are looking at “full threshold” disorders or subclinical symptoms. For example, someone with OCD who develops food-related rituals (like avoiding certain foods due to contamination fears) may not technically meet criteria for an eating disorder, but their behaviors still overlap.

Why the Overlap? Shared Features and Mechanisms

So, why are eating disorders and OCD so closely linked? Researchers believe there are multiple pathways.

Symptom overlap

Both conditions involve intrusive thoughts and repetitive behaviors. For example:

  • Obsessive thoughts: In eating disorders, it might be constant thoughts about calories, weight, or forbidden foods. In OCD, it might be contamination fears, symmetry obsessions, or intrusive harm thoughts.
  • Ritualistic behaviors: People with anorexia might weigh food to the gram, eat in a rigid order, or exercise compulsively. These are behaviors that mirror the compulsions seen in OCD (Halmi et al., 2005).

Perfectionism and control

Perfectionism, rigidity, and a strong desire for control are hallmark traits in both disorders. Many individuals describe a need for “just right” experiences. Whether it’s perfectly arranging food or perfectly completing a compulsion (Pollack et al., 2013).

Please note: while OCD can manifest with perfectionistic traits, not all perfectionism is OCD.

Cognitive inflexibility

Both eating disorders and OCD are associated with difficulties in cognitive flexibility, which is the ability to shift thoughts or behaviors when circumstances change. This rigidity keeps both disorders stuck in repetitive patterns (Dakanalis et al., 2024).

Biological overlap

Neuroimaging studies suggest that similar brain regions, particularly those involved in habit learning and error detection, are implicated in both disorders (International OCD Foundation, 2023a). 

Genetic studies also show shared heritability, meaning that the same genetic vulnerabilities may contribute to both conditions (Pollack et al., 2013).

Diagnostic Challenges

Distinguishing between ED and OCD symptoms

One of the biggest challenges for clinicians is determining whether certain behaviors are driven by an eating disorder or by OCD.

For example:

  • Cutting food into tiny pieces may be an anorexia-related ritual, but if it’s about symmetry rather than calories, it could be OCD.
  • Avoiding “unsafe” foods could be about fear of weight gain (ED) or fear of contamination (OCD).

The key is looking at the underlying motivation: is it about weight/shape or about neutralizing anxiety from intrusive thoughts? Or is it both? (International OCD Foundation, 2023b).

Impact on prognosis

Research shows that when OCD and eating disorders co-occur, the prognosis can be more severe. People with both conditions often experience:

  • Longer illness duration
  • Higher relapse rates
  • More functional impairment (Selles et al., 2022)

This makes early detection and integrated treatment especially important.

Treatment Considerations

Treating eating disorders and OCD together can be complicated, but there are evidence-based approaches that work.

Psychotherapy

  • CBT (Cognitive Behavioral Therapy) is the gold-standard for eating disorders, focusing on reducing food restriction, binge-purge cycles, and body image distortions.
  • ERP (Exposure and Response Prevention) is the gold-standard for OCD, helping people face their fears while resisting compulsions.
  • In comorbid cases, therapists often blend techniques. For instance, ERP can be used for food-related fears while CBT addresses weight and body image concerns (Steinglass et al., 2006).
  • Family-Based Therapy (FBT) is often effective for younger individuals with comorbid OCD and eating disorders.

Medication

  • SSRIs (Selective Serotonin Reuptake Inhibitors) are the frontline medications for OCD.

Multidisciplinary care

Because eating disorders affect both mental and physical health, treatment usually requires a multidisciplinary team: a therapist, psychiatrist, dietitian, and/or sometimes a primary care doctor or medical specialist. 

This ensures that both the psychological and medical complications are addressed.

Key Takeaways on Eating Disorders and OCD

  • Eating disorders and OCD often go hand in hand. Many people who struggle with one also experience symptoms of the other, which can make recovery feel especially complicated.
  • They share similar traits. Perfectionism, rigid routines, intrusive thoughts, and ritualistic behaviors show up in both conditions. That’s why they can sometimes look alike on the surface.
  • The difference is in the “why.” In OCD, rituals are usually about reducing anxiety or preventing something “bad” from happening. In eating disorders, behaviors are usually tied to food, weight, or body image. Understanding this distinction is key for proper treatment.
  • Comorbidity adds complexity. When eating disorders and OCD overlap, it often means symptoms are more intense, harder to treat, and more likely to stick around without the right help.
  • Recovery is possible. Even though having both can feel overwhelming, people do get better. With the right combination of therapy, support, and sometimes medication, it’s absolutely possible to break free from the cycle and build a healthier relationship with food, body, and mind.

Thanks for reading!

Rachel Beiler, MHS, RD, LDN

References

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  • International OCD Foundation. (2023b). Are eating disorders part of the OCD spectrum? Retrieved from https://iocdf.org/expert-opinions/are-eating-disorders-ocd/
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