Metabolic Ketogenic Diet and Mental Health Conditions Three
Comorbid Psychosis and Eating Disorder
Having a psychosis spectrum condition alongside an eating disorder does happen. I was able to locate two case reports in a 2020 emerging evidence paper for treating these co-occurring conditions with ketogenic therapy. I am going to transpose the details rather than just point to the table within the paper, although I encourage you to go review all the case examples (most do not have a co-occurring eating disorders).
Case #2
Female 31 years, schizoaffective disorder, with other psychiatric diagnoses: anorexia nervosa and major depressive disorder.
Medication history: sertraline, bupropion, amphetamine salts, lorazepam, lamotrigine, divalproex, topiramate, risperidone, aripiprazole, quetiapine, olanzapine, and clozapine; 23 ECT; lack of symptom control.
Ketogenic diet for 4 months.
A brief explanation here is needed regarding positive and negative symptoms for schizophrenia. It does not mean the symptoms are experienced as positive or negative ones, rather it clusters symptoms into what I would call active and passive expression. Hallucinations, delusions, disorganized speech and behaviour are all “positive” or active, whereas withdrawal, flat affect, apathy, little speech are “negative” or passive.
For Case #2, positive symptoms of schizophrenia dropped from 24 to 15, negative symptoms from 29 to 18 and general symptoms from 46 to 28. She broke the diet and severe paranoia and delusion returned but were brought in line with a return to the diet. She maintains on a dose of aripiprazole that was previously insufficient to manage her symptoms.
Case #6
Female 39 years, hallucinations and paranoia started age 14, diagnosed with schizophrenia at age 24. Other psychiatric diagnoses: major depressive disorder, anxiety and anorexia nervosa.
Medication history: haloperidol, clozapine, ziprasidone, risperidone, quetiapine, aripiprazole, olanzapine, sertraline, paroxetine, citalopram, fluoxetine, duloxetine, and venlafaxine.
Ketogenic diet started in 2003 has remained psychosis free for 5 years and completely off all medications. Symptoms of paranoia, hallucinations and suicide ideation all remitted. [1]
N=2 doesn’t tell us much of course. I think what I would point out here is that those medication lists for both cases are very, very long. It indicates that for these individuals, they were both navigating very life-limiting and severe symptoms for decades where the available treatments were essentially providing little improvement in quality of life.
Secondary psychosis can occur due to starvation and it will resolve with refeeding. However, it’s also extremely difficult to determine at times whether there are two distinct conditions or one condition that is causing symptoms to overflow into a second condition.[2]
The ketogenic diet is not just a difficult diet to stay on, it can also be very dangerous. Many with eating disorders have co-occurring diabetes (either Type 1 or 2) and a ketogenic diet can shoot someone into a hypoglycemic state that can be life threatening. It is a diet contraindicated for those with any history of liver or kidney disease, and it’s worth noting that any Covid infection, whether it was symptomatic at all in the acute phase or not, can result in long term damage and progressive impairment of the kidneys and liver. [3],[4]
It is for you and your healthcare practitioner to ensure you have the proper workup before attempting a ketogenic diet; that you have nailed down your own medical mind; that you understand and wish to take the risks of the diet when compared to the impaired quality of life and trajectory you have experienced with symptoms to date; and that you have exhausted all other avenues that have far better clinical data to support their use. Hopefully, in the next few years the clinical data on ketogenic diets for mental health conditions will advance in leaps and bounds and that last proviso can be removed from the assessment list completely.
Just Eating Disorder
To make matters more convoluted, one recent paper suggests that perhaps anorexia is a kind of self-generated effort to ease anxiety symptoms by placing the brain, through starvation, into mild ketosis. [5] However, a systematic review and meta-analysis (also in 2025) found that ketogenic diets had only modest improvements for depressive symptoms and “no significant associations were found for anxiety in randomized clinical trials.” [6]
And while it seems as though no solid evidence is piling up for treating anxieties with the ketogenic diet, there are now case reports popping up indicating remission from refractory anorexia nervosa is possible with a ketogenic diet.
There is a 2023 case series suggesting full remission (from 1-5 years in duration) using a ketogenic diet for those with severe and enduring anorexia nervosa. The researchers interviewed three patients via telemedicine, reviewed their medical charts and conducted medical interviews. An animal-based ketogenic diet was used for treatment including: fatty beef and lamb, fatty fish, bacon, egg yolks and organ meat (thymus, heart, bone marrow). [7] Notably, all three of them chose to pursue these diets after many years of severe restriction of food and multiple failed attempts at weight restoration. Their introduction to the ketogenic diet was from online sources exclusively and the decision to embark on the diet was self-directed. The ages at which they began their ketogenic diets were 37, 25, and 48, respectively. The 48-year-old had maintained her remission for 5 years at the time of publication submission.
Truly, this is tantalizing stuff! In all sincerity, I think this might be quite exciting. In each one of these cases, we are looking at individuals who crashed out of numerous attempts to recover and realize remission. Quality of life was limited and deteriorating for many, many years for each of them.
But I do think it’s important for me to frame all of this (even beyond the warnings I have mentioned above of the dangers of the diet itself for contraindicated conditions etc.) and I’ll do so in the final part of this series.
Part Four April 17.
Sarnyai Z, Palmer CM. Ketogenic therapy in serious mental illness: emerging evidence. International Journal of Neuropsychopharmacology. 2020 Jul;23(7):434-9.
Almeida B, Almeida H, Castro L. Starving brain: the clinical challenge differentiating anorexia nervosa and psychosis-a case report. European Psychiatry. 2020 Jul 2;63.
Mayamba Nlandu Y, Tannor EK, Bamikefa TA, Rissassi Makulo JR. Kidney damage associated with COVID-19: from the acute to the chronic phase. Renal Failure. 2024 Dec 31;46(1):2316885.
Lebbe A, Aboulwafa A, Bayraktar N, Mushannen B, Ayoub S, Sarker S, Abdalla MN, Mohammed I, Mushannen M, Yagan L, Zakaria D. New onset of acute and chronic hepatic diseases post-COVID-19 infection: a systematic review. Biomedicines. 2024 Sep 10;12(9):2065.
Micali N, Miletta MC, Clemmensen C, Pappaianni E, Lazeyras F, Cuenoud B, Sandi C. Providing alternative fuel for the brain in anorexia nervosa: a review of the literature on ketones and their effects on metabolism and the brain. Translational psychiatry. 2025 Oct 17;15(1):412.
Janssen-Aguilar R, Vije T, Peera M, Al-Shamali HF, Meshkat S, Lin Q, Lou W, Laviada-Molina H, Phillips ML, Bhat V. Ketogenic diets and depression and anxiety: A systematic review and meta-analysis. JAMA psychiatry. 2026 Jan;83(1):13-22.
Norwitz NG, Hurn M, Forcen FE. Animal-based ketogenic diet puts severe anorexia nervosa into multi-year remission: A case series. Journal of Insulin Resistance. 2023 Jun 14;6(1):84.
