A ketogenic diet may improve symptoms of depression, according to a new review and meta-analysis published in JAMA Psychiatry.
Effects were strongest overall in trials that confirmed a state of ketosis, used stricter carb limits, or included participants who were not obese. Experts said the findings point to the diet as a plausible adjunct therapy to standard psychiatric care in select patients. The research underscores a broader shift toward treating psychiatric conditions through a metabolic lens.
The analysis “adds weight to a growing field connecting metabolic dysfunction and psychiatric illness,” said Jasmine Sawhne, MD, MBA, psychiatrist in private practice in Los Angeles, who was not involved with the research. The paper “positions the ketogenic diet not as a fad but as a potential metabolic intervention for brain-based disorders.”
Previous research has indicated the keto diet may be beneficial for patients with major depressive disorder and bipolar disorder.
The analysis included 50 studies published between 1965 and 2025 that analyzed associations between the keto diet and mental health conditions, including depression and anxiety. More than 41,000 participants aged 18 years or older were included in the mix of randomized control trials, quasi-experimental studies, cohort studies, and cross-sectional studies. Symptom reduction was assessed using one or more validated psychiatric scales.
Participants in randomized trials who did not have obesity showed greater improvements in symptoms (standardized mean difference [SMD], -0.88) than did those with obesity (SMD, -0.11). The difference between subgroups was statistically significant (P = .04).
Within the controlled trials, very low-carb diets, defined as less than or equal to 10% of daily energy from carbs, were more effective than low-carb diets, which involved consuming 11%-20% of calories from carbs. The mean difference in depression scores between very low and control diets was -0.79 vs -0.05 for low-carb diets (P = .01).
Reported side effects of keto diets were generally mild and included fatigue, nausea, and constipation. One serious event, euglycemic ketoacidosis, was noted in a participant taking an SGLT2 inhibitor.
Randomized controlled trials that required monitoring to confirm a state of ketosis reported the largest reductions in depressive scores.
The results are “moderately promising, with some caveats,” said Venkat Bhat, MD, MSc, director of the Interventional Psychiatry Program at St. Michael’s Hospital in Toronto, Ontario, Canada, who led the study. “Monitoring likely improves treatment fidelity. It confirms exposure, reinforces adherence, enables troubleshooting, and reduces exposure misclassification, factors that can strengthen observed effects.”
The analysis found no association between the diet and symptoms of anxiety.
Based on the findings, clinicians should consider the ketogenic diet for some patients with depression “cautiously, and as an adjunct, not a replacement, for standard care,” Bhat said.
They should also screen for contraindications like the use of an SGLT2 inhibitor, incorporate ketone monitoring, and provide referrals to dietary counseling, he said.
Patients who are reluctant to take medications for depression may be particularly interested in trying the diet, said David Miklowitz, PhD, distinguished professor of psychiatry in the Division of Child and Adolescent Psychiatry at the UCLA Semel Institute, who was not involved with the study.
“A lot of people favor more natural approaches to their psychiatric disorder rather than just one pharmaceutical after another, and that’s a population that very well might benefit from the keto diet,” Miklowitz said.
Sawhne cautioned that a keto diet is not for every patient because “they can be difficult to sustain and may have risks if not medically supervised. The real takeaway is that brain health is metabolic health,” Sawhne said.
The study reported receiving no funding. Bhat, Sawhne, and Miklowitz reported having no relevant financial conflicts of interest.
Brittany Vargas is a journalist covering medicine, mental health, and wellness.