Adherence to the EAT-Lancet diet and neuropsychiatric disorders: a systematic review and meta-analysis

Neuropsychiatric disorders (NPDs) are a leading cause of disability worldwide. The predominantly plant-based EAT-Lancet diet has been proposed to confer neuropsychiatric benefits, yet evidence remains limited. This study synthesized associations between adherence to the EAT-Lancet diet and neuropsychiatric outcomes. We searched PubMed, Web of Science, Embase, Scopus, and ProQuest Dissertations and Theses Global through September 4, 2025. Observational studies reporting associations between EAT-Lancet adherence and NPDs were included. Binary outcomes were pooled as hazard ratios (HRs) or odds ratios (ORs), and continuous outcomes as regression coefficients (β). Subgroup, sensitivity, and publication-bias analyses were performed. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). Twenty-two cohort and six cross-sectional studies were included. Higher adherence to the EAT-Lancet diet was associated with lower risks of depression (OR 0.76; 95% CI 0.71-0.81), anxiety (OR 0.82; 0.76-0.89), stroke (HR 0.84; 0.76-0.92), and dementia (HR 0.96; 0.93-1.00), whereas no significant association was observed for global cognitive function (β 0.02; -0.01 to 0.06). Sensitivity analyses supported robustness. Certainty of evidence was very low for anxiety, depression, and cognition, and low for stroke and dementia. Greater adherence to the EAT-Lancet diet was associated with lower risks of depression, anxiety, stroke, and dementia. However, given the low certainty of evidence, findings should be interpreted cautiously. Further large prospective studies and randomized controlled trials are warranted to improve evidence quality and clarify the potential role of the EAT-Lancet diet in neuropsychiatric disease prevention.