Published in the journal Nutrients, the review looked at findings from 19 studies that explored links between diet and mental health in adolescents. Overall, healthier eating patterns were commonly associated with fewer symptoms of depression. In contrast, lower-quality diets were more often linked to higher levels of psychological distress.

Whole Diet vs. Supplements

The researchers examined six randomized controlled trials and 13 prospective cohort studies. Their analysis found mixed evidence when it came to individual nutrient supplements. For example, some results suggested that vitamin D might help reduce depressive symptoms in teens, but the findings were not consistent.

On the other hand, broader dietary patterns showed clearer trends. Diets that emphasized overall quality and balance were more consistently linked to better mental health outcomes than focusing on single nutrients alone.

Why Adolescence Matters

The authors emphasize that adolescence is a key stage for brain development and emotional health. This period offers an important window for prevention and early support. Diet stands out as a factor that can be changed and scaled across populations since it is part of everyday life.

At the same time, the researchers note that current evidence is not fully consistent. Factors such as socioeconomic status and sex may influence how diet relates to mental health, making the relationship more complex.

Gaps in the Evidence

The review also aimed to make the findings more relevant to real-world settings by looking beyond strictly clinical populations. The goal is to better inform both healthcare practices and public health strategies.

However, the researchers highlight major gaps in the existing literature. Much of the current research focuses on depression, while other important outcomes such as anxiety, stress, externalizing behaviors, self-esteem and aggression have received far less attention.

A Roadmap for Future Research

To move the field forward, the authors propose a detailed roadmap for future studies. They recommend more exposure-based research designs, the inclusion of biological markers, and better standardization across studies. They also call for open science practices and a broader range of mental health outcomes to be examined.

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: “Overall, our findings suggest that public health and clinical strategies should prioritise whole-diet approaches over isolated supplementation when considering adolescent mental health. However, further high-quality research is needed to determine which dietary patterns are most effective and for whom.”