Eating Disorders and Disordered Eating: Neurobiology, Treatment, and Cultural Context

Overview

Eating disorders are among the most lethal psychiatric conditions in existence. Anorexia nervosa carries the highest mortality rate of any mental illness — approximately 5-6 times the expected mortality rate for age-matched populations, with death resulting from cardiac complications, organ failure, or suicide. Bulimia nervosa, binge eating disorder, and their variants inflict profound suffering on millions of individuals and their families, affecting an estimated 9% of the global population at some point in their lives.

Yet eating disorders remain profoundly misunderstood. They are not lifestyle choices, vanity problems, or failures of willpower. They are complex neuropsychiatric conditions with significant genetic heritability (50-80% for anorexia), identifiable neurobiological mechanisms, and treatment responses that vary dramatically by disorder subtype. The cultural narrative that eating disorders are simply about “wanting to be thin” obscures the anxiety, compulsivity, interoceptive dysfunction, and reward circuitry dysregulation that drive these conditions at a biological level.

The broader category of “disordered eating” — which includes restrictive patterns, emotional eating, yo-yo dieting, orthorexia, body dysmorphia, and unhealthy compensatory behaviors that don’t meet full diagnostic criteria — affects a far larger population and exists on a continuum with clinical eating disorders. Diet culture, the $72 billion weight loss industry, and the pervasive moralization of food choices create a toxic environment that normalizes disordered relationships with food and pushes vulnerable individuals across the threshold into clinical illness.

This article examines eating disorders through neurobiological, psychological, and cultural lenses, exploring evidence-based treatments while also challenging the cultural systems that create the conditions for these disorders to flourish.

Clinical Eating Disorders

Anorexia Nervosa

Anorexia nervosa is characterized by persistent restriction of energy intake leading to significantly low body weight, intense fear of gaining weight or becoming fat, and disturbance in the way body weight or shape is experienced. It exists in two subtypes: restricting type (weight loss through diet, fasting, and/or excessive exercise) and binge-purge type (restriction punctuated by episodes of binge eating and compensatory purging).

The medical consequences of anorexia are devastating and affect every organ system. Cardiac complications (bradycardia, hypotension, arrhythmias, cardiac atrophy, mitral valve prolapse) are the leading cause of death. Endocrine disruption includes hypothalamic amenorrhea, low estrogen/testosterone, growth hormone resistance, elevated cortisol, and thyroid suppression. Bone density loss begins within the first year and can be irreversible — osteoporosis in individuals in their twenties and thirties. Gastrointestinal complications include delayed gastric emptying, constipation, and superior mesenteric artery syndrome. Neurological effects include brain volume loss (partially reversible with refeeding), cognitive impairment, and peripheral neuropathy.

Bulimia Nervosa

Bulimia nervosa involves recurrent episodes of binge eating (consumption of objectively large amounts of food with a sense of loss of control) followed by compensatory behaviors (self-induced vomiting, laxative or diuretic abuse, excessive exercise, or fasting). Unlike anorexia, individuals with bulimia typically maintain a normal or above-normal body weight, which contributes to underdiagnosis.

Medical complications specific to purging include esophageal tears (Mallory-Weiss), dental enamel erosion, parotid gland enlargement, Russell’s sign (calluses on knuckles from self-induced vomiting), electrolyte disturbances (particularly hypokalemia, which can cause fatal cardiac arrhythmias), and metabolic alkalosis. Laxative abuse causes colonic dysmotility and electrolyte derangement that may persist long after cessation.

Binge Eating Disorder (BED)

BED — the most common eating disorder, affecting approximately 2-3% of the population — involves recurrent binge eating without regular compensatory behaviors. Episodes are associated with eating rapidly, eating until uncomfortably full, eating large amounts when not hungry, eating alone due to embarrassment, and feeling disgusted, depressed, or guilty afterward.

BED was only recognized as a distinct diagnosis in DSM-5 (2013), reflecting longstanding underappreciation of non-purging eating disorders. It is strongly associated with obesity, depression, anxiety, and reduced quality of life. Unlike simple overeating, BED involves compulsive, dissociative, and loss-of-control elements that distinguish it from volitional excess consumption.

Orthorexia Nervosa

Orthorexia — an obsessive preoccupation with eating only foods deemed “healthy” or “pure” — is not yet an official DSM diagnosis but is increasingly recognized by clinicians. It typically begins with genuinely health-motivated dietary changes that progressively become rigid, anxiety-driven, and socially impairing. Individuals with orthorexia may spend hours planning meals, experience intense anxiety when “impure” food is unavailable, and progressively eliminate food groups until their diet is dangerously restricted.

The wellness industry, clean eating movement, anti-nutrient discourse, and social media health influencer culture provide a socially acceptable container for orthorexic behavior — making it uniquely difficult to identify, as the obsessive restriction is validated and even celebrated by the individual’s social environment.

ARFID (Avoidant/Restrictive Food Intake Disorder)

ARFID involves persistent failure to meet nutritional needs, not driven by body image concerns or weight fears (distinguishing it from anorexia). Instead, avoidance is driven by sensory sensitivity (texture, taste, smell aversion), fear of aversive consequences (choking, vomiting, allergic reaction), or apparent lack of interest in food. ARFID is increasingly recognized in children and adults, particularly those with autism spectrum disorder, anxiety disorders, or sensory processing differences.

Neurobiology of Eating Disorders

Serotonin and Anxiety

Serotonin dysfunction plays a central role in anorexia and bulimia. Individuals with anorexia show elevated serotonin activity in the recovered state — suggesting that their baseline neurochemistry involves excessive serotonergic tone, which manifests as anxiety, perfectionism, and harm avoidance. Starvation reduces tryptophan availability (the serotonin precursor), thereby reducing serotonin activity and providing paradoxical anxiety relief. This creates a neurochemical trap: the individual learns that not eating reduces anxiety, powerfully reinforcing restrictive behavior.

In bulimia, serotonin dysregulation manifests differently: low serotonin activity (associated with impulsivity and emotional instability) contributes to binge episodes, while the purge provides temporary emotional regulation. SSRIs (fluoxetine at 60 mg, the only FDA-approved medication for bulimia) address this serotonin deficit, reducing binge-purge frequency by approximately 50%.

Reward Circuitry

The dopamine reward system is implicated across eating disorders. In anorexia, neuroimaging studies show altered reward processing — the anticipation of food activates anxiety circuits rather than reward circuits, while weight loss and exercise activate reward pathways. The disorder effectively rewires the reward system to find pleasure in deprivation rather than nourishment.

In BED, the reward circuitry shows patterns similar to substance addiction: heightened reward sensitivity to food cues, reduced prefrontal inhibitory control, and escalating consumption to achieve diminishing reward (tolerance). This neurobiological overlap between BED and substance use disorders has implications for treatment (naltrexone, which blocks opioid receptors involved in food reward, shows benefit in BED).

Interoceptive Dysfunction

Interoception — the awareness of internal body states (hunger, fullness, temperature, heartbeat, emotion) — is consistently impaired across eating disorders. Individuals with anorexia have difficulty recognizing hunger signals. Those with bulimia and BED have difficulty recognizing fullness. This interoceptive disconnection means that eating disorder patients cannot rely on body signals to guide eating, necessitating structured meal plans and external cues during recovery.

Evidence-Based Treatments

Family-Based Treatment (Maudsley Approach)

Family-Based Treatment (FBT), developed at the Maudsley Hospital in London, is the most evidence-supported treatment for adolescent anorexia nervosa. FBT externalizes the eating disorder (“the anorexia” is separate from the child), empowers parents as the primary agents of refeeding (rather than relying on the adolescent’s impaired judgment about food), and progresses through three phases: parental control of eating, gradual return of autonomy to the adolescent, and establishing healthy adolescent identity.

RCTs demonstrate that FBT achieves full remission in approximately 50% of adolescents with anorexia and partial remission in an additional 25%, significantly outperforming individual therapy approaches. The key insight of FBT is that an individual in the grip of a brain-based illness that fears food cannot be expected to choose to eat — an external scaffolding of loving authority is required until the brain heals enough to resume self-directed eating.

CBT-Enhanced (CBT-E)

CBT-E, developed by Christopher Fairburn, is the leading evidence-based treatment for bulimia nervosa, BED, and adult eating disorders across the spectrum. CBT-E addresses the transdiagnostic mechanisms maintaining eating disorders: overvaluation of shape and weight, dietary restraint, binge eating and compensatory behaviors, low self-esteem, perfectionism, and interpersonal difficulties.

The treatment follows a structured 20-session protocol (or 40 sessions for complex cases) including self-monitoring of eating behavior, establishing regular eating patterns, identifying and challenging shape/weight overvaluation, and relapse prevention. CBT-E achieves sustained remission in approximately 50-60% of bulimia patients and similar rates for BED.

Intuitive Eating

Intuitive Eating, developed by Evelyn Tribole and Elyse Resch, provides a framework for healing the relationship with food that is particularly relevant for disordered eating and eating disorder recovery. Its ten principles include rejecting diet mentality, honoring hunger, making peace with food, challenging the food police, discovering satisfaction, feeling fullness, coping with emotions without using food, respecting the body, exercising for enjoyment, and honoring health with gentle nutrition.

Research on Intuitive Eating shows associations with lower BMI, better psychological wellbeing, improved metabolic health markers, and reduced disordered eating behaviors. It is not a weight loss intervention — it is a framework for normalizing the relationship with food and body, which may or may not result in weight change.

Health at Every Size (HAES)

The HAES paradigm, while controversial, challenges the assumption that weight is a reliable indicator of health and that weight loss should be a primary therapeutic goal. HAES principles include weight inclusivity, health enhancement (supporting health behaviors regardless of weight outcome), respectful care, eating for wellbeing, and life-enhancing movement.

HAES is supported by evidence that: weight stigma itself is a significant health risk (increasing cortisol, inflammation, and avoidance of healthcare); intentional weight loss attempts fail long-term in 95% of cases and predict subsequent weight gain; and health behaviors (physical activity, adequate nutrition, stress management) improve health outcomes independently of weight change. Critics argue that HAES minimizes the genuine health risks of severe obesity. The nuanced position recognizes that both weight stigma and extreme obesity carry health risks, and that promoting health behaviors without weight-focused shame produces better outcomes than weight-focused interventions.

Diet Culture Critique

The $72 Billion Problem

The weight loss industry — encompassing diet programs, supplements, surgery, apps, and food products — generates $72 billion annually in the US alone. This industry profits from creating dissatisfaction with normal bodies, promoting unsustainable interventions, and generating repeat customers when weight is inevitably regained. The 95% long-term failure rate of diets is not a market failure — it is the business model.

Diet culture extends beyond the weight loss industry to encompass the moralization of food choices (“clean eating,” “guilt-free,” “cheat meals”), the valorization of thinness as a moral and aesthetic ideal, the equation of dietary restriction with virtue, and the social surveillance of eating behavior. This cultural milieu creates the psychological conditions — body dissatisfaction, food anxiety, restrictive eating — that are the most consistent predictors of eating disorder onset.

Wellness Culture as Diet Culture in Disguise

The contemporary wellness movement has repackaged diet culture in more palatable language. “Detoxing” replaces “dieting.” “Clean eating” replaces “calorie counting.” “Optimizing” replaces “restricting.” But the underlying message — that your body as it is requires fixing, that food is primarily a tool for body modification, and that restriction is a form of self-improvement — remains unchanged. For individuals with eating disorder vulnerability, the wellness culture can be as dangerous as overt diet culture because its restrictive messages come wrapped in the language of health.

Clinical and Practical Applications

Early identification of eating disorders saves lives. Warning signs include preoccupation with food, weight, or body shape; progressive food restriction; excessive exercise despite injury or fatigue; meals skipping or eating in secret; bathroom visits after meals; use of diet pills, laxatives, or diuretics; significant weight change; social withdrawal; and dental enamel erosion.

Screening tools include the SCOFF questionnaire (5 questions with high sensitivity) and the EAT-26. All practitioners should be familiar with medical emergencies in eating disorders: refeeding syndrome (potentially fatal electrolyte shifts when malnourished individuals resume eating — requires medical monitoring for the first 7-14 days), cardiac arrhythmias from electrolyte disturbance, and suicidal ideation.

Treatment should be provided by teams specialized in eating disorders, as well-intentioned but untrained practitioners can inadvertently cause harm. The hierarchy of treatment settings ranges from outpatient (for medically stable patients) through intensive outpatient (IOP), partial hospitalization (PHP), residential treatment, and inpatient medical stabilization.

Four Directions Integration

• Serpent (Physical/Body): Eating disorders are diseases of the body-mind disconnect — the body’s hunger and fullness signals are overridden, its nutritional needs ignored, and its wisdom rejected. The serpent calls us back to the body: learning to hear hunger, to feel fullness, to trust the body’s inherent wisdom about what and how much to eat. Recovery is, at its core, a return to embodiment — re-inhabiting a body that was abandoned in service of the disorder.

• Jaguar (Emotional/Heart): Eating disorders are emotional survival strategies — they manage anxiety, numb pain, create a sense of control, and provide identity when other sources of meaning are insufficient. The jaguar asks what emotional wound the eating disorder is trying to heal, what pain it is trying to manage, what fear it is trying to control. Addressing these emotional roots — not just the eating behaviors — is essential for lasting recovery.

• Hummingbird (Soul/Mind): The soul perspective sees eating disorders as crises of meaning — the reduction of a rich human life to the pursuit of a number on a scale. Recovery involves expanding identity beyond body and food, reconnecting with values, passions, and purposes that give life meaning independent of weight or shape. The hummingbird seeks the sweetness of a life fully lived, not the empty aesthetics of a body perfected.

• Eagle (Spirit): From the eagle’s perspective, the epidemic of eating disorders reflects a culture profoundly disconnected from the sacred nature of the body and of food. When food is moralized, bodies are commodified, and thinness is worshipped, we have created a spiritual crisis masquerading as a health movement. The eagle calls for a radical reorientation: seeing the body as sacred, food as gift, and nourishment as a spiritual practice of self-love.

Cross-Disciplinary Connections

Eating disorders connect to psychiatry (diagnosis, neurobiology, psychopharmacology), psychology (CBT, family therapy, motivational interviewing), neuroscience (serotonin, dopamine, interoception), endocrinology (amenorrhea, bone metabolism, metabolic adaptation), cardiology (arrhythmias, cardiac remodeling), gastroenterology (gastroparesis, refeeding), nutrition science (meal planning, nutritional rehabilitation), sociology (diet culture, beauty standards, social media), and feminist studies (gendered body ideals, power dynamics).

Key Takeaways

• Anorexia nervosa has the highest mortality rate of any psychiatric disorder — approximately 5-6 times expected mortality, from cardiac complications and suicide
• Eating disorders are neuropsychiatric conditions with 50-80% heritability, not lifestyle choices or failures of willpower
• Starvation reduces serotonin activity and paradoxically reduces anxiety, creating a neurochemical trap that reinforces restrictive eating
• Family-Based Treatment (Maudsley approach) achieves approximately 50% full remission in adolescent anorexia — the strongest evidence base for this population
• CBT-Enhanced achieves approximately 50-60% sustained remission in bulimia nervosa and binge eating disorder
• Intuitive Eating and HAES provide frameworks for healing disordered eating that prioritize wellbeing over weight
• The wellness industry can serve as diet culture in disguise — “clean eating” and “detoxing” can mask restrictive eating disorder patterns
• 95% of diets fail long-term; the weight loss industry’s business model depends on this failure to generate repeat customers
• All practitioners should recognize warning signs and know that refeeding syndrome is a medical emergency requiring supervised management

References and Further Reading

• Arcelus, J., Mitchell, A. J., Wales, J., & Nielsen, S. (2011). Mortality rates in patients with anorexia nervosa and other eating disorders: a meta-analysis of 36 studies. Archives of General Psychiatry, 68(7), 724-731.
• Lock, J., Le Grange, D., Agras, W. S., Moye, A., Bryson, S. W., & Jo, B. (2010). Randomized clinical trial comparing family-based treatment with adolescent-focused individual therapy for adolescents with anorexia nervosa. Archives of General Psychiatry, 67(10), 1025-1032.
• Fairburn, C. G. (2008). Cognitive Behavior Therapy and Eating Disorders. New York: Guilford Press.
• Kaye, W. H., Fudge, J. L., & Paulus, M. (2009). New insights into symptoms and neurocircuit function of anorexia nervosa. Nature Reviews Neuroscience, 10(8), 573-584.
• Tribole, E., & Resch, E. (2020). Intuitive Eating: A Revolutionary Anti-Diet Approach (4th ed.). New York: St. Martin’s Essentials.
• Bacon, L. (2010). Health at Every Size: The Surprising Truth About Your Weight. Dallas: BenBella Books.
• Tomiyama, A. J. (2019). Stress and obesity. Annual Review of Psychology, 70, 703-718.
• Bulik, C. M., Sullivan, P. F., Tozzi, F., et al. (2006). Prevalence, heritability, and prospective risk factors for anorexia nervosa. Archives of General Psychiatry, 63(3), 305-312.