New Research on the Benefits of a Keto Diet for Depression
The emerging field of psychonutrition offers more tools for treating depression.
Posted November 22, 2025 | Reviewed by Margaret Foley
This month’s publication in JAMA Psychiatry, by researchers from the University of Toronto, Canada, shows small to moderate improvements in depressive symptoms when people are on a ketogenic diet (randomized clinical trials with a total of 50 studies and 41,718 participants). [1]
What is a ketogenic diet?
A ketogenic diet (keto diet) is high in fat, moderate in protein, and low in carbohydrates. The standard keto diet consists of 70 to 80 percent fats, 10 to 20 percent proteins, and 5 to 10 percent carbohydrates. So, on a keto diet, people eat very little sugar and consume mostly meat, fish, eggs, nuts, seeds, cheese, and oils such as olive oil.
Three ways the ketogenic diet can influence mental health
It is interesting to note that there is a bidirectional relationship between what we eat and depression. While poor dietary habits can worsen depression symptoms, depression itself can lead to unhealthy eating habits, leading to a vicious cycle. The key is to stop this cycle.
The emerging field of psychonutrition and the benefits of the Mediterranean diet
The emerging field of psychonutrition highlights the importance of diet in psychiatric care. [4]
Despite the ketogenic diet being in the spotlight recently, the most evidence-based diet for reducing depressive symptoms and incidence is the Mediterranean diet, rich in fruits, vegetables, whole grains, fish, nuts, seeds, plain yogurts, and healthy fats such as olive oil and avocados, and limited in processed foods and sugar-sweetened beverages.
This Mediterranean diet provides key nutrients like omega-3 fatty acids (which support brain health and reduce inflammation) [5], antioxidants from fruits and vegetables [6], and probiotics (there is an association between gut-health-promoting diet and depression). [7]
But what is also important is to supplement the diets of depressed people with the micronutrients they might be lacking.
Micronutrient deficiencies commonly observed in depressed people include:
It is important to measure those serum micronutrients and to supplement them if there is a deficiency.
The new field of psychonutrition teaches us how important our diet is for our mental health.
Recent studies show the benefits of a ketogenic diet, while older studies emphasize the benefits of the Mediterranean diet. What both diets have in common is that they recommend we stay away from sugar and ultra-processed foods.
So, to stay healthy and emotionally balanced, let’s say no to cakes, cookies, and sugary drinks.
[1] Janssen-Aguilar R, Vije T, Peera M, et al. Ketogenic Diets and Depression and Anxiety: A Systematic Review and Meta-Analysis. JAMA Psychiatry. Published online November 05, 2025. doi:10.1001/jamapsychiatry.2025.3261 from University of Toronto, Canada.
[2] The Ketogenic Diet Through a Metabolomic Lens: Biochemical Pathways, Therapeutic Applications, and Analytical Challenges. Idzikowska K, Gątarek P, Gajda A, et al. Nutrients. 2025;17(18):2969. doi:10.3390/nu17182969.
[3] The Ketone Metabolite Β-Hydroxybutyrate Blocks NLRP3 Inflammasome-Mediated Inflammatory Disease. Youm YH, Nguyen KY, Grant RW, et al. Nature Medicine. 2015;21(3):263-9. doi:10.1038/nm.3804.
[4] Biological Role of Nutrients, Food and Dietary Patterns in the Prevention and Clinical Management of Major Depressive Disorder. Ortega MA, Fraile-Martínez Ó, García-Montero C, et al. Nutrients. 2022;14(15):3099. doi:10.3390/nu14153099.
[5] Nutritional Interventions in Depression: The Role of Vitamin D and Omega-3 Fatty Acids in Neuropsychiatric Health. Raza ML, Hassan ST, Jamil S, Fatima W, Fatima M. Clinical Nutrition (Edinburgh, Scotland). 2025;45:270-280. doi:10.1016/j.clnu.2025.01.009.
[6] Linking What We Eat to Our Mood: A Review of Diet, Dietary Antioxidants, and Depression. Huang Q, Liu H, Suzuki K, Ma S, Liu C. Antioxidants (Basel, Switzerland). 2019;8(9):E376. doi:10.3390/antiox8090376.
[7] The Association Between Gut-Health Promoting Diet and Depression: A Mediation Analysis. Lai CCW, Boag S. Journal of Affective Disorders. 2023;324:136-142. doi:10.1016/j.jad.2022.12.095.
[8] Dietary Nutrient Deficiencies and Risk of Depression (Review Article 2018-2023). Zielińska M, Łuszczki E, Dereń K. Nutrients. 2023;15(11):2433. doi:10.3390/nu15112433.
[9] The Role of Water-Soluble Vitamins and Vitamin D in Prevention and Treatment of Depression and Seasonal Affective Disorder in Adults. Jahan-Mihan A, Stevens P, Medero-Alfonso S, et al. Nutrients. 2024;16(12):1902. doi:10.3390/nu16121902.
[10] Zinc, Magnesium, Selenium and Depression: A Review of the Evidence, Potential Mechanisms and Implications. Wang J, Um P, Dickerman BA, Liu J. Nutrients. 2018;10(5):E584. doi:10.3390/nu10050584.
[11] Serum and Urinary Essential Trace Elements in Association With Major Depressive Disorders: A Case-Control Study. Fu J, Wang Q, Wang N, et al. Frontiers in Psychiatry. 2023;14:1297411. doi:10.3389/fpsyt.2023.1297411.
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Chris Gilbert, M.D., Ph.D. , is a physician and writer specializing in holistic, integrative, and mind-body medicine and the author of “The Listening Cure,” 2017 (SelectBooks).
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