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A systematic review and meta-analysis evaluated the effects of dietary interventions on depression and anxiety in adults. The review found that calorie-restrictive and low-fat diets may reduce depression symptoms in those with high cardiometabolic risk, but the certainty of these findings is low.

Evidence on other diets, comparisons of diets to active interventions, and other outcomes is limited, prompting researchers to recommend further exploration in areas including the add-on effect of dietary intervention alongside first-line treatment for depression and/or anxiety.

The study is published in Annals of Internal Medicine.

Researchers from Bond University in Queensland reviewed data from 25 randomized controlled trials (RCTs) involving over 57, 000 adults evaluating the effect of dietary advice with or without food provision compared with usual eating habits on depression and/or anxiety for at least three months.

The diets studied in the RCTs included calorie restriction, low-fat diets, and Mediterranean-style diets.

The primary outcome was change in depression and/or anxiety severity, and secondary outcomes included incidence of depression and anxiety and quality of life (QoL).

The researchers found that compared with usual care, calorie restriction and a low-fat diet may reduce depressive symptoms in adults with elevated cardiometabolic risk, however, their effect on anxiety is uncertain.

Compared with other diets, low-fat diets may lower anxiety, but the evidence is uncertain for its effect on depression.

The evidence is also uncertain of the effect of a Mediterranean-style diet on depression, anxiety and QoL compared with no specific dietary advice.

Overall, while calorie restriction and low-fat diets could reduce depressive symptoms in certain groups, the researchers had low confidence in the findings and recommend patients discuss any dietary changes with a health care professional before implementing changes.

More information: Moderate To Long Term Effect of Dietary Interventions for Depression and Anxiety: A Systematic Review and Meta-Analysis, Annals of Internal Medicine (2025). DOI: 10.7326/ANNALS-24-03016  Journal information: Annals of Internal Medicine