OCD & Anorexia
By Kyle King
I was diagnosed with OCD when I was 12. I was put into treatment rather promptly, and after about a year of concentrated exposure and response prevention therapy, I recovered.
Five years later, as a junior in high school, I approached my parents and told them that I thought I had an eating disorder. I told them that I couldn’t stop thinking about food, calories, what types of roasted vegetables would up the most volume in my stomach while introducing the least fat. I told them all this, and they told me it sounded like OCD. They took me to the same OCD treatment clinic that had fixed my problems before but, this time, it didn’t work.
As you can probably guess, I was eventually diagnosed with an eating disorder — specifically, anorexia nervosa. The OCD treatment clinic my parents put me into tried to treat my eating disorder the way they knew — as if it was OCD — and I got worse. I was eventually taken out of that clinic and transferred to the intensive outpatient program at the University of California, San Diego. It was here that my entire family was introduced to family-based therapy. It completely changed our perspective, our treatment course, and frankly, our lives.
I tell you all of this not to rag on my parents for thinking that my thoughts and behaviors were just another flavor of OCD. Honestly, I can’t blame them. On the surface, the cognitive mechanisms that sustain both disorders are very similar. In both cases, there’s an obsession — a thought or feeling — followed by an action reducing or preventing obsession-related anxiety. In OCD, this could be something like germs and hand-washing; in an eating disorder, this could be something like calories and restricting. Similar vibes.
But the similarities don’t stop there. OCD and eating disorders (specifically anorexia nervosa) have shared genetic overlaps, and patients with both conditions show similar areas of alteration on fMRI, implying that the neurobiology of the two may be closely related. Going beyond biology, patients with both OCD and eating disorders tend to share similar personality traits: rigidity, perfectionism, and an inclination for ritual. It comes as no surprise, then, that people with an eating disorder are at higher risk of developing OCD than the general population — and that those with OCD are at higher risk of developing an eating disorder as well.
As such, I can’t blame my parents, or anyone, for mixing the two up. But it is important to try to keep them separate.
The goal of this essay isn’t to explain the similarities and differences between eating disorders and OCD in clinical and scientific terms. I leave that to the clinicians and scientists. Instead, the goal here is to reflect on my internal experience of the two disorders in an attempt to provide insight into the patient experience. Additionally, I want to share how I — as someone who has lived with both — differentiate the two from one another in myself, and to discuss why it’s so important that patients and parents do the work of differentiating.
Similarities in The Internal Experience of My Eating Disorder and OCD
Both OCD and my eating disorder consumed me. Both took up every available corner of my mind and dedicated it to thinking about the thing I was most afraid of. They both thrived on rules. The more I followed them, the more rigid they became, and the more limited my life got. A significant portion of my cognitive power when suffering from both conditions was spent constructing, remembering, and applying rules that slowly tightened their grip around my neck.
Both conditions also demanded certainty. That is, all day long, both demanded me to predict all the scary things that might lay ahead — whether that was walking into a classroom I believed might be contaminated, or eating a dish that might have had too much butter — and spend my mental energy trying to minimize any and all “threats”. At my worst, there was no room left for anything in my mind other than trying to feel certain and safe in the face of that threat.
Differences in The Internal Experience of My Eating Disorder and OCD
One difference that stands out to me is the character of the worry itself. In OCD, so many of my thoughts revolved around what if questions (e.g., what if someone contaminated this before me? what if it dropped on the floor?). In anorexia, by contrast, the biology of weight gain made those what if questions disappear. I didn’t ask what if I ate another cookie—because there was no what if to be had. More calories meant weight gain, and that was that. In this way, the worry in anorexia felt almost more imprisoning, because it was so absolute.
Another difference has to do with the timing of triggers. In both conditions, I was always anticipating the next threatening moment — but in OCD, triggers tended to be somewhat sporadic. When I was scared of mold, I was always thinking about it, but actual exposure was intermittent and at least somewhat unpredictable. My eating disorder worked differently. I knew I was going to come into contact with food. I knew roughly when, and with whom. Because of this, anorexia felt even more relentlessly present. I could always think very concretely about the next meal, the next threat, and ruminate. With OCD, because I couldn’t always be sure exactly when the feared thing would appear, it felt like I had at least some room to breathe.
Yet another difference comes in what it actually felt like to follow the rules. In OCD, if I washed my hands properly or successfully avoided something I believed was contaminated, I was flooded with relief — I felt good. In anorexia, if I restricted as much as I possibly could at a meal, I suppose I was “safe” by anorexia’s standards, but I was also physically deteriorating. And because of that, I never felt that same sense of good. Truthfully, I rarely felt good at all — I was so poorly nourished that I almost didn’t have the biological capacity to feel anything other than hunger.
This brings me to another difference that I find myself thinking about often. While both disorders felt ever-present, anorexia always felt just a little more total. I think that was for two reasons. First, when I was starving, my brain could not think about anything other than food. This is evolutionarily hardwired into us — and for good reason: if the body needs fuel, it will commandeer the mind to get it. Because of this, there was rarely a moment when my mind wasn’t pulled back to thoughts of food. Second, food was everywhere. My OCD fear — mold — was not something I encountered on every street corner. I didn’t walk past storefronts celebrating mold or sit through conversations about the best new mold spot in town. Food, as we all know, is omnipresent in every culture. And that made the thoughts feel inescapable in a way that OCD, even at its worst, never quite did.
A Word About Interaction Between the Two
Some report that their OCD made their eating disorder worse, others that their eating disorder made their OCD worse, and others still that day the two barely touched each other. For me, my eating disorder made my OCD significantly worse. Mechanistically, I think it came down to nutrition. When I was at my lowest weight and running the kind of calorie deficit I was running, it was almost as if I had no energy left to suppress the obsessions I had worked so hard to fight since I was 12. They came back with force. And as I began to gain weight, those obsessions started to quiet until I was weight restored, and they were gone.
How To Tell The Two Apart And Why It Matters
The section above was meant to give you a sense of how these disorders feel from the inside — the similarities, and the differences. But as a parent, your primary question is probably more practical: how do I tell them apart? Even if they feel different from the inside, at the end of the day, both disorders are basically some obsession followed by a behavior designed to get rid of the anxiety that obsession creates. So how do you distinguish one from the other?
As someone who has had both, the most reliable method I’ve found is simple: keep asking why.
Let me explain. While OCD and eating disorders can look identical on the surface, the behaviors you notice are often motivated by very different impulses. Thus, the most reliable way to figure out whether a presenting behavior is rooted in OCD or an eating disorder is to understand the function it serves. If the reason behind the behavior is something related to calories, weight, or body image — it’s probably a symptom of the eating disorder. If the reason is something like contamination, checking, or practically any other motivation that isn’t tied to food or body image — it’s probably OCD. Psychologists call this functional analysis — examining a behavior to understand the function it serves — and I think it gets you about 95% of the way there when it comes to disentangling which symptoms belong to which disorder.
Let me give you some examples. When I was 12, I refused to eat chicken parmesan. On the surface, that might look like an eating disorder behavior. But if you had asked me why, I would have told you that I’d eaten it once when I felt contaminated, and that the dish itself had become contaminated in my mind. Upon functional analysis, this behavior sure sounds like OCD to me.
Here’s another example. When I was 17, I would wash my hands an obscene number of times after cooking any meal. That clearly must be OCD, right? Maybe — but if you asked me why, I would have told you it was because I didn’t want any residual fat on my hands that might provide some unknown calories. Upon functional analysis, this just might be an eating disorder behavior after all.
As I hope these examples illustrate, just looking at the behavior can be pretty misleading. To figure out whether something is driven by OCD or an eating disorder, you have to look beyond the behavior itself and try to understand why the person is doing what they’re doing. You have to get to the function.
Early in treatment, I used to think trying to categorize behaviors as secondary to the eating disorder or OCD wasn’t more than a semantic game. Now as someone who has recovered from both, I would argue it is much more than semantics. The two disorders, while very similar, are treated differently and one does not always respond to the treatments designed for the other. I experienced this firsthand, shunted into exposure and response prevention therapy — the gold standard treatment for OCD — for what was actually an eating disorder. Because of this easy miscategorization, I was mistreated, got worse, and became medically unstable. I’m not going to try to explain the many psychological and pharmacological treatments available for these two disorders because there are people out there far better equipped to do that than I am, but the main point I want to make is this: telling these two disorders apart is much more than figuring out what label to give the school guidance counselor. It can be a matter of life and death.
It’s worth noting that this piece is based entirely on my own personal experience with both disorders, and my experience is just one of many. And while I hope the frameworks I’ve shared have been helpful, life is pretty messy. Mental illness — and the path out of it — is rarely cut and dry. Not every symptom can be placed into a neat diagnostic box every single time. And that’s okay. Perfection is not required to get better. Slow progress wins out in the end.
Lord knows I had a messy go of it with both disorders. I also had a hell of a time getting back on my feet. But I did both times and your kid can too.
Keep up the fight.
Kyle King is a second-year medical student at the Yale School of Medicine and a mental health advocate with lived experience of OCD and Anorexia Nervosa.
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