Could Ketogenic Diets Transform the Treatment of Anorexia?

Anorexia nervosa represents one of psychology's most challenging conditions. With mortality rates five times higher than the general population and relapse rates exceeding 50%, traditional treatment approaches have left many patients trapped in cycles of restriction, weight restoration, and relapse. Current evidence-based treatments show disappointingly low efficacy, with the majority of patients experiencing treatment failures.

However, recent research is revealing an unexpected therapeutic avenue: the therapeutic ketogenic diet. This metabolic intervention challenges current understanding of treating anorexia nervosa.

The Metabolic Psychology Framework

Recent publications in the Journal of Insulin Resistance and Frontiers in Nutrition present evidence that anorexia nervosa may be fundamentally a metabolic-psychiatric disorder rather than purely a psychological condition. This reframing opens new treatment possibilities that address the neurobiological roots of the illness.

Case Evidence

The evidence comes from detailed case studies of three patients with severe anorexia nervosa who achieved sustained remission using animal-based ketogenic diets. These were not mild cases—their body mass indices (BMIs) had reached life-threatening lows of 10.7, 13.0, and 11.8 kg/m² respectively. All had failed to respond to standard treatment approaches.

The first published case report documented a 29-year-old woman with severe and enduring anorexia nervosa of 15 years duration who achieved complete remission following a ketogenic diet combined with ketamine infusions. Her illness began at age 14.5 with an effort to "eat healthy" at summer camp, which quickly spiralled into severe restriction. For 15 years, she continued eating restrictively and exercising compulsively, with her weight stable around 56.8 kg but living an increasingly limited life. After three months on a ketogenic diet, she reported being "30-40% better," and subsequent ketamine infusions led to complete symptom resolution. As she described: "I know this sounds ridiculous, but I am no longer anorexic. I had so many rules I didn't even know them. But they are gone."

Additionally, the first published case report of ketogenic diet treatment for anorexia nervosa documented a remarkable individual recovery. A 29-year-old woman with severe and enduring anorexia nervosa of 15 years duration achieved complete remission following a novel treatment combining a ketogenic diet with ketamine infusions.

Katherine., a 39-year-old woman, had battled anorexia for over a decade. At her lowest weight of 32 kg (BMI 10.7), she was consuming only 100 calories daily—essentially just lettuce with stevia sweetener. After cardiac arrest and multiple hospitalisations, she discovered educational materials about ketogenic diets for mental health. Upon adopting a high-fat animal-based diet, she experienced what she described as "mental calm and clarity" and reduced anxiety around food. She gained 22 kg within months and has maintained her recovery for over two years.

Trevor., a 26-year-old man, had dropped to 39.9 kg (BMI 13.0) during university whilst pursuing an athletic physique. Standard "all foods fit" treatment approaches actually worsened his anxiety, creating a destructive binge-restrict cycle. When he adopted a ketogenic diet at age 25, he reported that it "changed my life completely," with complete cessation of anxious thoughts around food and exercise. His weight stabilised at a healthy 64 kg, and his testosterone levels normalised from severely low levels.

Amelia., a 53-year-old woman with a three-decade struggle with anorexia, described her first experience eating steak on the ketogenic diet as an "emotional epiphany." She reported: "I don't know how else to describe it but when I ate those three bites of that steak, [it was as if] receptors lit up in my brain and I cried tears of joy." She has remained in remission for almost five years.

Remarkably, all three patients scored 0/5 on eating disorder screening questionnaires at follow-up, indicating complete symptom resolution.

The Neurobiological Mechanism

Why might ketogenic diets succeed where traditional approaches fail? The answer lies in understanding anorexia as a disorder of brain energy metabolism.

The Anxiety-Glucose Dysfunction Cycle

Research suggests that individuals predisposed to anorexia nervosa experience a fundamental problem: high anxiety and stress levels interfere with brain glucose utilisation. While stress increases the brain's glucose requirements, it paradoxically reduces glucose utilisation in key brain regions including the frontal cortex, thalamus, and hippocampus.

This creates a vicious cycle:

1. High anxiety → Impaired brain glucose utilisation
2. Brain energy deficit → Worsened anxiety and cognitive symptoms
3. Food restriction → Ketosis provides alternative brain fuel
4. Temporary symptom relief → Reinforces restrictive behaviour

Ketosis as Brain Rescue

When the body enters ketosis—whether through starvation or dietary intervention—ketone bodies (particularly β-hydroxybutyrate and acetoacetate) become the brain's primary fuel source. Crucially, ketone metabolism appears less susceptible to stress-induced disruption than glucose metabolism.

Neuroimaging studies demonstrate that ketogenic diets dramatically alter brain glucose utilisation. Specifically, elevated blood ketone levels reduce brain glucose uptake whilst enhancing blood flow, supporting neuroprotective effects. This metabolic shift affects key brain regions involved in anorexia pathophysiology, including areas responsible for body perception, reward processing, and anxiety regulation.

GABA and Anxiety Reduction

Ketogenic diets enhance γ-aminobutyric acid (GABA) production in the brain through increased glutamate conversion. GABA is the brain's primary inhibitory neurotransmitter, directly reducing anxiety. Animal studies confirm that elevated ketone levels reduce stress and anxiety behaviours—precisely the symptoms that drive anorexia nervosa.

Studies using the activity-based anorexia animal model have shown that ketamine, an NMDA glutamate receptor antagonist, can rescue animals from self-starvation when administered during the early stages of the behaviour. This research provided the rationale for adding ketamine to ketogenic diet treatment in clinical cases.

Clinical Trial Evidence

Building on case reports, researchers conducted a pilot clinical trial with five weight-recovered anorexia patients who continued experiencing significant eating disorder symptoms. Participants adopted a therapeutic ketogenic diet for 8 weeks, with some receiving additional ketamine infusions.

The results were notable:

• Significant improvements across all eating disorder measures
• Reduced clinical impairment scores
• Decreased eating, shape, and weight concerns
• Improved acceptance of self and body
• Enhanced social and emotional connection
• Stable weight maintenance throughout treatment

Most importantly, the steepest improvements occurred before adding ketamine, suggesting the ketogenic diet alone was highly effective. Four of five participants maintained recovery for at least 12 months post-treatment.

The Combined Treatment Approach

The original case report demonstrated that combining ketogenic diet with ketamine could produce dramatic results. After three months on the ketogenic diet showed partial improvement, the patient received four ketamine infusions over two weeks at gradually increasing doses to achieve therapeutic dissociation.

Her response was remarkable. As she described: "I had so many rules I didn't even know them. But they are gone. I can exercise because it feels good. It isn't that I have to. I can stop when I want to."

Her depression scores (PHQ-9) dropped from 13 to 6 after the first ketamine treatment, and to 2 following the third infusion. Most significantly, her recovery has persisted for over six months, including through the severe stressors of the COVID-19 pandemic.

 Challenging Current Ineffective Treatment Approaches

These findings directly challenge current treatment paradigms. Standard anorexia treatment typically emphasises "all foods fit" approaches, explicitly discouraging food restrictions. The rationale is that any dietary restriction might trigger eating disorder behaviours.

However, this research suggests that for some patients, unrestricted eating patterns may worsen anxiety and perpetuate binge-restrict cycles.

A focus on calories rather than nutrition typically results in rapid and distressing weight gain with no improvement in psychiatric symptoms or malnutrition.

A therapeutic ketogenic diet provides quality nutrition, structure and control whilst simultaneously addressing the underlying neurobiological dysfunction.

As one study participant explained: "Trying to reverse my anorexia with an 'all-foods-fit' diet just made my anxiety much worse and, even though I gained weight, I felt horrible, mentally and physically. But when I started a carnivorous diet, my life changed! My anxiety diminished and I felt I could relax."

The Adaptation to Flee Famine Hypothesis

The case report patient was presented with an etiological theory known as the "Adaptation to Flee Famine Hypothesis," which frames anorexia as fundamentally metabolic rather than psychological. This theory posits that it would have been evolutionarily advantageous for some tribal members to respond uniquely to food scarcity—denying hunger, dismissing body inanition, and engaging in hyperactive behaviour to lead the tribe to better hunting grounds.

This metabolic framework resonated deeply with the patient, who had often felt she was battling invisible forces. Understanding her symptoms as distorted physiological signals rather than personal failings was powerfully motivating and countered narratives about "choosing" the disorder for "control."

The Metabolic Psychiatry Framework

These findings align with the emerging field of metabolic psychiatry, which recognises that psychiatric disorders often involve fundamental metabolic dysfunction. Rather than treating symptoms alone, metabolic interventions target the underlying cellular and neurochemical abnormalities driving illness.

For anorexia nervosa, this means:

• Recognising metabolic dysfunction as primary, not secondary
• Addressing brain energy metabolism directly
• Using nutritional interventions as first-line treatments
• Understanding that successful recovery requires metabolic healing

Safety and Implementation Considerations

Implementing ketogenic diets in anorexia requires careful medical supervision. The research involved medically stable, weight-recovered patients rather than severely underweight individuals. Key considerations include:

• Medical monitoring of electrolytes, cardiac function, and metabolic markers
• Ensuring adequate caloric intake to prevent further weight loss
• Regular assessment of eating disorder symptoms and behaviours
• Integration with psychological support and therapy
• Recognition that ketogenic diets replace "starvation ketosis" with "nutritional ketosis"

The original case report patient was monitored closely throughout treatment. Her physical examination remained normal, as did laboratory tests including complete blood count, electrolytes, liver and kidney function. Importantly, her weight increased rather than decreased during ketogenic diet treatment, reaching her pre-illness weight of 61.3 kg (136 pounds) and remaining stable.

When ketamine was added to treatment, careful protocols were followed with continuous monitoring of vital signs, gradual dose titration, and management of side effects such as dissociation and mild nausea. The patient tolerated treatment well without serious adverse effects.

Hope for Treatment-Resistant Patients

For patients who have struggled through multiple treatment attempts, metabolic interventions offer genuine hope. Both the case series and original case report demonstrate that even individuals with decades of illness and multiple treatment failures can achieve sustained recovery.

As Katherine from the case series reflected: "My high-fat carnivore diet saved me, and I feel I can do anything. I'm never going back to the way I was."

The original case report patient expressed similar sentiments: "All these years, I was still in there watching, waiting, and hoping to escape. Every single interaction now is a new freedom."

Most remarkably, these recoveries have persisted through significant challenges. The case series patients maintained recovery for years, whilst the original case report patient's remission survived the extreme stressors of living in New York City during the COVID-19 pandemic.

Weight Restoration and Psychological Recovery

Both studies demonstrate that metabolic interventions can achieve the dual goals that have traditionally been difficult to accomplish simultaneously: weight restoration and psychological recovery. The original case report patient's weight progression tells this story clearly—from her pre-illness weight of 61.7 kg, dropping to dangerous lows of 42.6 kg during acute illness, and ultimately returning to her healthy pre-illness weight of 61.7 kg after treatment.

Importantly, her relationship with weight and body image fundamentally transformed. As she described when weighing herself post-recovery: "I really didn't know how I would feel getting on a scale and looking at my weight. Now, I am so relieved. I think I do not CARE about the number because I can SEE myself now in the mirror, so the number on the scale is 'like' ONE source of information, but not the ONLY one."

A New Chapter in Anorexia Treatment

The therapeutic ketogenic diet represents more than just another treatment option—it embodies a fundamental shift in understanding anorexia nervosa as a metabolic disorder with psychological manifestations rather than a psychological disorder with metabolic consequences.

Whilst this research is still in its early stages, the evidence is substantial enough to warrant serious scientific attention. For a field that has struggled with limited treatment options and high relapse rates, metabolic psychiatry approaches offer new hope.

The journey from case reports to established treatment will require rigorous research, careful implementation, and open-minded evaluation. However, for patients trapped in the cycle of anorexia nervosa, a metabolic approach may finally offer a pathway to sustained recovery and renewed life.

References

Calabrese, L., Scolnick, B., Zupec-Kania, B., Beckwith, C., Costello, K., & Frank, G. K. W. (2022). Ketogenic diet and ketamine infusion treatment to target chronic persistent eating disorder psychopathology in anorexia nervosa: A pilot study. Eating and Weight Disorders, 27, 3751-3757.

Frank, G. K. W., & Scolnick, B. (2024). Therapeutic ketogenic diet as treatment for anorexia nervosa. Frontiers in Nutrition, 11, 1392135.

Norwitz, N. G., Hurn, M., & Forcen, F. E. (2023). Animal-based ketogenic diet puts severe anorexia nervosa into multi-year remission: A case series. Journal of Insulin Resistance, 6(1), a84.

Scolnick, B., Zupec-Kania, B., Calabrese, L., Aoki, C., & Hildebrandt, T. (2020). Remission from chronic anorexia nervosa with ketogenic diet and ketamine: Case report. Frontiers in Psychiatry, 11, 763.

The research discussed represents emerging science and should not replace established medical care. Anyone considering ketogenic interventions for eating disorders should work closely with qualified healthcare professionals experienced in both metabolic approaches and eating disorder treatment.