A new study led by researchers at Swansea University suggests that what teenagers eat may play an important role in their mental health. The team also outlines priorities for future research aimed at clarifying how diet and psychological well-being are connected during adolescence.
Published in the journal Nutrients, the review examined findings from 19 studies investigating links between diet and mental health in adolescents. Across the available evidence, healthier overall dietary patterns were more consistently associated with fewer depressive symptoms. Lower-quality diets, by contrast, were more often linked to higher levels of psychological distress.
The researchers analyzed six randomized controlled trials and 13 prospective cohort studies. When examining individual nutrient supplements, the results were mixed. Some studies suggested that vitamin D supplementation could help reduce depressive symptoms in teenagers, but these findings were not consistently replicated across the research.
In contrast, broader dietary patterns produced clearer and more reliable signals. Diets emphasizing overall quality, balance, and healthier food choices were more consistently associated with positive mental health outcomes than approaches focused on individual nutrients alone.
The authors emphasize that adolescence is a critical period for brain development and emotional regulation, making it an important window for prevention and early intervention. Diet also represents a potentially scalable public health strategy because it is a modifiable factor that forms part of everyday life.
At the same time, the review highlights that the current evidence base is not entirely consistent. The relationship between diet and mental health may be influenced by factors such as socioeconomic status and sex, adding complexity to the interpretation of findings.
The researchers also sought to make the review’s conclusions more relevant beyond strictly clinical settings, with the goal of better informing healthcare practice and public health initiatives.
However, the authors identified significant gaps in the existing literature. Much of the research has focused on depression, while other important outcomes—including anxiety, stress, externalizing behaviors, self-esteem, and aggression—have received considerably less attention.
To strengthen future research, the team proposes a roadmap that includes more rigorous exposure-based study designs, greater use of biological markers, and improved standardization across studies. They also call for wider adoption of open science practices and for future work to examine a broader range of mental health outcomes.
The research was supported by the Cognitive Health Committee of the Institute for the Advancement of Food & Nutrition Sciences (IAFNS).
Corresponding author Professor Hayley Young of Swansea University’s School of Psychology said the findings suggest that public health and clinical strategies should prioritize whole-diet approaches rather than isolated supplementation when considering adolescent mental health. She also emphasized that more high-quality research is needed to determine which dietary patterns are most effective and for whom.
