Ketogenic Diets and Depression and Anxiety: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials and quasi-experimental studies
PubMed 41191382 · doi:10.1001/jamapsychiatry.2025.3261
What was done
A systematic review and random-effects meta-analysis evaluated the association between ketogenic diets (<26% energy from carbohydrates or <50 g/day) and psychiatric outcomes in adults (aged ≥18 years) measured with validated scales. Searches across MEDLINE, Embase, and APA PsycINFO were conducted through April 18, 2025. Randomized clinical trials (RCTs) and quasi-experimental (QSE) studies were synthesized separately using standardized mean differences (SMDs) and standardized mean changes (SMCCs).
What was found
Across 50 included studies (41,718 participants), 10 RCTs for depressive symptoms showed a significant benefit for ketogenic diets compared with control diets (SMD, -0.48; 95% CI, -0.87 to -0.10; I² = 67.2%). Effects were stronger in studies with ketone monitoring, nonobese participants, very low-carbohydrate protocols, and non-high-carbohydrate comparators. In 9 RCTs for anxiety, no significant association was observed (SMD, -0.03; 95% CI, -0.18 to 0.12; I² = 41%). In QSE studies, ketogenic diets were associated with reductions in both depressive symptoms (9 studies; SMCC, -0.66; 95% CI, -0.83 to -0.50; I² = 0%) and anxiety symptoms (6 studies; SMCC, -0.58; 95% CI, -0.81 to -0.36; I² = 0%).
Why it matters
This review synthesizes randomized and non-randomized evidence to show that ketogenic diets may modestly improve depressive symptoms when ketosis is verified, while highlighting that randomized evidence currently fails to support an effect on anxiety.
Limits
The randomized evidence for depression had substantial heterogeneity (I² = 67.2%), short follow-up periods, and varied by comparator diet. Inconsistency between RCTs and quasi-experimental studies for anxiety suggests open-label confounding in uncontrolled designs.
Cited by
- partial Ketogenic dietary interventions have been shown in meta-analyses published in JAMA Psychiatry to therapeutically address mental health disorders including anxiety disorders, schizophrenia, and bipolar disorder.