Why “One Size Fits All” Eating Disorder Treatment Is Failing & What We Should Do Instead

For decades, we’ve been telling people with eating disorders essentially the same thing: learn to eat all foods in moderation, challenge your food rules, and the problem will resolve. This message has become gospel in the eating disorder field. And for decades, treatment outcomes have remained stubbornly poor.

A new meta-analysis published in 2025 finally puts numbers to what many of us have suspected: after four decades of psychological treatment research, more than 70% of patients with bulimia nervosa and 55% with binge eating disorder fail to achieve abstinence from their core symptoms [1]. Even more troubling, outcomes for binge eating disorder have actually declined over time. 

Let that sink in. Forty years of research. No meaningful improvement in outcomes.

As a clinician-researcher who has spent years at the intersection of nutrition, addiction neurobiology, and trauma, I believe it’s time for an honest conversation about why the eating disorder field has stalled—and what the emerging science tells us we need to do differently.

The Problem with “All Foods Fit”

The dominant treatment philosophy in eating disorder care can be summarized in a single phrase: all foods fit. There are no “bad” foods. Restriction is the enemy. Everyone gets the same approach, whether they’re recovering from anorexia or struggling with compulsive overeating.

Here’s the uncomfortable truth: this one-size-fits-all approach was developed primarily with restrictive eating disorders in mind. It was then broadly applied to binge eating pathology without sufficient regard for the neurobiological heterogeneity that exists across the eating disorder spectrum. The theories were developed before binge eating disorder was an official diagnosis.

In my published work, I’ve argued that we need to separate those whose eating pathology stems from psychological mechanisms (such as body dissatisfaction and shame leading to restriction) from those with biologically-based mechanisms (such as chronic exposure to ultra-processed foods altering reward circuitry) and that the trauma-addiction link is a primary clue [2,3]. These are fundamentally different presentations that require some different treatment approaches, or at least an understanding of their differences. 

And I’m not alone in this thinking anymore.

The Science of Subtyping: A New Direction

One of the most important studies published in 2025 comes from researchers who did something deceptively simple: they stopped treating binge eating as a single entity and asked whether different subtypes might exist based on underlying mechanisms [4].

What they found confirmed what I’ve been observing clinically for years. Using neurobehavioral assessments and brain imaging, researchers identified three distinct subtypes among people with binge eating.

The Negative Emotionality Subtype: These individuals show high negative affect, emotion dysregulation, greater internalizing symptoms, and significant psychiatric comorbidity. For them, binge eating is primarily about managing overwhelming emotions. Treatment should focus on affect regulation and building tolerance to negative emotional states.

The Approach/Impulsive Subtype: This group shows higher impulsive behaviors, greater urgency, lower risk perception, and—critically—the highest rates of current substance use and past substance use disorders among all subtypes. They also have the lowest levels of dietary restraint. Let that register: the people most likely to struggle with addictive substances are also the ones least likely to restrict their food. Treatment for this group should target impulse control and self-regulation, potentially borrowing from addiction treatment models.

The Restrained/Overcontrolled Subtype: These individuals present with overcontrol, rigidity, higher risk perception, and harm avoidance. For them, cognitive flexibility interventions—not emotional interventions—are most likely to help.

This isn’t just academic categorization. This is precision medicine. Different mechanisms require different treatments. The field has known this intuitively for years but has been reluctant to act on it–because many people are afraid they will be ostracized for thinking differently.  

The Trauma Blind Spot

The eating disorder field has historically struggled to integrate trauma research—and it shows in our outcomes.

New research published in Biological Psychiatry highlights a concern for every clinician: future generations bear the brunt of stressors experienced by earlier generations [5]. Adverse experiences don’t just affect the individual; they can become biologically embedded through epigenetic mechanisms and transmitted across generations.

In my own research, I’ve found that 4 or more adverse childhood experiences (ACEs) predict ultra-processed food addiction symptoms—but notably does not significantly predict traditional eating disorder symptoms [6]. This distinction matters. It suggests that the pathways leading to addiction-like eating may be distinct from those leading to restriction-driven pathology.

What’s more, among those with a history of substance use disorder, the relationship between ACEs and ultra-processed food addiction is significantly stronger [6]. This speaks to shared vulnerability factors and cross-sensitization between substances of abuse and certain foods—a concept well-established in the addiction literature but still controversial in eating disorder circles.

Furthermore, research has shown that patients with complex PTSD and dissociative presentations have significantly higher symptom scores across eating disorders, depression, substance use, and anxiety [7]. Yet how many eating disorder programs routinely assess for PTSD, complex PTSD, or dissociation? How many modify their treatment approaches based on trauma history?

Ignoring trauma and addiction has only hurt the eating disorder field. The ignoring is not intentional or malicious, but simply due to a lack of understanding. 

The Addiction Neurobiology We Keep Ignoring

Here’s something that might upset some of my colleagues: eating disorder and substance use disorder research evolved independently, but their predominant theories share many of the same components [8]. Affect-based models? Present in both. Reward-based models? Present in both. Incentive sensitization? Present in both.

Yet the eating disorder field has been remarkably resistant to integrating addiction neuroscience—despite overwhelming evidence that it applies to a significant subset of patients.

Consider this recent finding: among individuals with binge eating and comorbid addiction (alcohol, nicotine, gambling, gaming), there was significantly higher impulsivity and lower self-control compared to those with binge eating alone [9]. Only the group with comorbid addiction showed impaired cognitive reappraisal in emotion regulation. The authors suggest these individuals may have difficulty managing negative emotions, contributing to both their binge eating and addictive behaviors [9].

This is not binge eating that will respond favorably to “all foods fit” messaging. This is binge eating driven by addiction-like mechanisms that require addiction-informed intervention.

In my earlier work, I proposed separating bulimia nervosa into two distinct subtypes: those who are hyporesponsive to reward (more similar to anorexia nervosa) versus those with hypersensitive reward circuitry (more similar to addiction). Same diagnosis, different neurobiology, different treatment needs.

What Ultra-Processed Foods Have to Do With It

I’ve been writing about ultra-processed food addiction for years—long before it was called “ultra-processed food use disorder” by a growing number of us. The resistance to this concept has been remarkable, even as the evidence has mounted.

Recent research has shown that childhood emotional maltreatment is associated with ultra-processed food addiction symptoms through deficits in reflective functioning [10]. These addiction symptoms then predict overeating behaviors and poor dietary control. In other words, there’s a clear pathway from early adversity to addiction-like eating that doesn’t pass through traditional eating disorder constructs.

Another study found that the relationship between ultra-processed food addiction and uncontrolled eating is fully mediated by binge eating thoughts and emotional eating [11]. The addiction symptoms don’t directly cause uncontrolled eating—they work through cognitive and emotional pathways that we can target therapeutically.

My recent structural equation modeling work found that PTSD symptoms almost entirely mediated the relationship between adverse childhood experiences and eating disorder symptoms. But UPFA symptoms explained 46% of the positive association between PTSD symptoms and eating disorder pathology [12].

Translation: if you’re not assessing for trauma AND addiction-like eating, you’re missing major pieces of the puzzle.

The Social Justice Distraction

I’ll say something controversial here: the eating disorder field has become so focused on certain social justice issues that we’ve lost sight of patient care. Identity politics has superseded clinical precision. Advocacy for body acceptance has morphed into a denial of addiction neurobiology. Fear of stigmatizing patients has led to the avoidance of difficult but necessary clinical conversations.

Meanwhile, our treatment outcomes haven’t improved in forty years [1].

I’m not suggesting that social justice issues don’t matter—they absolutely do. I’m suggesting that they shouldn’t prevent us from providing the most effective care possible. And right now, effective care means acknowledging that different patients need different approaches based on their underlying mechanisms, not ideological commitments.

What Needs to Change

Based on the emerging science, here’s what I believe the eating disorder field needs to do:

1. Embrace Subtyping. Stop treating all binge eating as the same phenomenon. Assess for negative emotionality, impulsivity/approach behaviors, and overcontrol. Match treatments to mechanisms [4].
2. Integrate Trauma Assessment and Treatment. Routinely screen for ACEs, PTSD, complex PTSD, and dissociation. Understand that patients with significant trauma histories may need fundamentally different approaches [7,12].
3. Stop Demonizing Addiction Frameworks. For some patients, addiction-like eating is real and needs to be addressed using principles borrowed from addiction treatment. This doesn’t mean every patient has food addiction—it means some do, and they deserve appropriate care or at least acknowledgement [3,8].
4. Acknowledge Ultra-Processed Foods. The “all foods fit” message may be appropriate for restriction-driven pathology but can be counterproductive for addiction-driven presentations. The science supports distinctions in food quality for certain subgroups [2,3].
5. Assess for Comorbidity. Substance use disorders, gambling, and other addictive behaviors are not coincidental findings—they suggest shared vulnerabilities that should inform treatment planning [6,9].
6. Fund Research on Differentiated Treatments. We need clinical trials that test whether subtype-matched treatments actually improve outcomes. The preliminary evidence suggests they should [4].

Closing Thoughts

I became a clinician to help people—not to defend treatment paradigms that aren’t working. When more than half of our patients aren’t achieving symptom abstinence after treatment, something is wrong. When outcomes aren’t improving despite decades of research, we need to ask hard questions.

Science is telling us that eating disorders are heterogeneous. That trauma matters. That addiction neurobiology is relevant. That ultra-processed foods affect some people differently than others.

It’s time we listened. The days of “one size fits all” are behind us.

References

1. Messer M, Linardon J, Engel M, Beilharz F, Sellbom M, Green M. Four decades of psychological treatment for bulimia nervosa and binge eating disorder: A meta-regression of changes in abstinence rates over time. 2025.
2. Wiss DA. A biopsychosocial overview of the opioid crisis: Considering nutrition and gastrointestinal health. Front Public Health. 2017;5:196.
3. Wiss DA. Clinical considerations of ultra-processed food addiction across weight classes: An eating disorder treatment and care perspective. Curr Addict Rep. 2022;9(4):255-267.
4. Brucar LR, Berner LA, Smith KE, et al. Mechanism-based subtyping in binge eating: Understanding neurobehavioral heterogeneity across negative emotionality, approach behavior, and executive function. 2025.
5. Taylor SM, Duffy EA, Bhattacharya A, et al. Towards understanding and halting legacies of trauma. Biol Psychiatry. 2025.
6. Wiss DA, Tran CD, LaFata EM. The association between cumulative adverse childhood experiences and ultra-processed food addiction is moderated by substance use disorder history among adults seeking outpatient nutrition counseling. Front Psychiatry. 2025;16:1543923.
7. Brewerton TD. PTSD, complex PTSD and the dissociative subtype of PTSD in patients with eating disorders. 2025.
8. Burr EK, Mason TB, Smith KE, Annunziato RA, Bhatt A, Laessle R. Integrating maintaining theories for addiction and binge-eating pathology: A review of affective and reward-based theories. 2025.
9. Jeong H, Lim J, Kim H, Park S. Cognitive and mental health profiles of binge-eating adults with and without comorbid addiction. 2025.
10. Rossi E, Cassioli E, Giraldi M, et al. The path from childhood emotional maltreatment to disordered eating behaviors: The role of reflective functioning and food addiction. 2025.
11. Rossi E, Cassioli E, Martelli M, et al. Tying food addiction to uncontrolled eating: The roles of eating-related thoughts and emotional eating. 2025.
12. Wiss DA, LaFata EM. Structural equation modeling of adverse childhood experiences, ultra-processed food intake, and symptoms of post-traumatic stress disorder, ultra-processed food addiction, and eating disorder among adults seeking nutrition counseling in Los Angeles, CA. Appetite. 2025;208:107938.