A Recipe for Resilience: A Systematic Review of Diet and Adolescent Mental Health

Adolescence is a critical period of vulnerability for the onset of mental health difficul-ties, presenting an urgent need for scalable prevention strategies. Diet is a universal, modifiable factor, yet its evidence base remains inconsistent. This systematic review synthesized evidence from controlled trials and prospective cohort studies investigat-ing the relationship between diet and mental health in adolescents aged 10–19 years. Searches were conducted to July 2025, and risk of bias was assessed. Nineteen studies met inclusion criteria: six intervention trials and thirteen cohort studies. Examined exposures included vitamin D, omega-3s, polyphenol-rich foods, Mediterranean-style diets, and overall diet quality. Across designs, healthier dietary patterns were often associated with fewer depressive symptoms, while poorer diet quality was linked to increased psychological distress. However, the current evidence is constrained by wide variation in assessments, small samples, and significant methodological limita-tions—particularly with high risk or some concerns noted in half of the included in-tervention trials—along with evidence suggesting that associations may differ by sex and are often sensitive to adjustment for socioeconomic status. Despite these chal-lenges, the findings confirm diet as a possible, actionable target for supporting ado-lescent mental health. This review concludes by proposing a detailed roadmap for fu-ture research, prioritizing harmonized symptom-based outcomes, biomarker-verified assessments, explicit analysis of sex and socioeconomic (SES) effects, and adequately powered trials to inform effective public health strategies for youth. Protocols were registered with PROSPERO (CRD42023413970) and archived on the Open Science Framework (https://osf.io/c6xze).