A new study by IRB CatSud and ISGlobal links teenagers’ nutrition with emotional wellbeing, cognitive performance, and long‑term decision‑making
Adolescence is a key period for brain development, and eating habits play an essential role in this process. A new study led by the Institut de Recerca Biomèdica Catalunya Sud (Southern Catalonia Biomedical Reseach Institute – IRB CatSud, formerly IISPV), includes the participation of the Barcelona Institute for Global Health (ISGlobal), a centre supported by the “la Caixa” Foundation, shows that eating ultra‑processed foods is linked to more emotional and behavioural difficulties. On the other hand, following the Mediterranean diet is associated with better executive function. The study, titled Dietary Patterns and Neuropsychological Function in Adolescents: A Cross-sectional and Longitudinal Study, has been published in BMC Medicine.
The study, carried out by the Clinical and Epidemiological Neuroscience Research Group (NeuroÈpia) at IRB CatSud. The research analyses data from a sample of 653 adolescents aged 12 to 16 from the metropolitan area of Barcelona (Smart-Snack study). It highlights the importance of nutrition during adolescence, a stage where the brain is still developing, especially the prefrontal cortex, which is involved in decision‑making and impulse control.
Eating habits were assessed using food‑frequency questionnaires that measured adherence to the Mediterranean diet and the intake of ultra‑processed foods. Neuropsychological function was evaluated through standardised computerised tests that measured attention, working memory, fluid intelligence, decision‑making, and emotional recognition. Behavioural and emotional outcomes were also assessed using validated questionnaires.
Opposite effects on the teen brain
The results show clear differences between the two eating patterns. According to Alexios Manidis, the lead researcher, a higher intake of ultra‑processed foods—such as sugary drinks, industrial pastries, and ultra-processed meats—is linked to poorer performance in emotional recognition and sustained attention. Teenagers who consume more ultra‑processed foods also report more symptoms of anxiety and depression, as well as more behavioural problems.
In contrast, greater adherence to the Mediterranean diet—rich in fruits, vegetables, legumes, and olive oil—is linked to fewer behavioural problems and better scores in executive attention.
However, in the six-month follow-up, only initial ultra-processed food consumption showed longitudinal associations with internalizing symptoms and decision-making, while Mediterranean diet adherence showed no longitudinal effects. “This may suggest that Mediterranean diet benefits require ongoing adherence, while the effects of ultra-processed foods may be more persistent,” comments Manidis, reinforcing the importance of maintaining healthy habits consistently.
Objective validation through biomarkers
The study also analysed urinary biomarkers in a subsample of 257 participants. The results show that adolescents who consume more ultra‑processed foods have fewer compounds from plant‑based foods and more compounds linked to food processing, confirming the reliability of dietary questionnaires.
Christopher Papandreou, Assistant Professor at the Hellenic Mediterranean University (Crete, Greece) and senior co-author of the study, notes that “teenagers’ diets are shifting towards ultra-processed foods” and warns that this change “may be contributing to the rise in mental health problems among young people”.
Jordi Julvez, head researcher of the NeuroÈpia Research Group at the IRB CatSud and ISGlobal, reminds us that “adolescence is a period of great brain reorganisation” and explains that diet “can influence how teenagers regulate their emotions and make complex decisions”.
The researchers conclude that future strategies, such as replacing processed snacks in schools with nutrient‑dense options like nuts and fresh fruit, could be effective in improving emotional regulation and cognitive function in the long term.
Bibliographic reference of the study
Manidis, A., Ayala-Aldana, N., Bernardo-Castro, S., Pinar-Martí, A., Galkina, P., Fernández-Barrés, S., Ramirez-Carrasco, P., Lamuela-Raventós, R. M., Papandreou, C., & Julvez, J. (2026). Dietary patterns and neuropsychological function in adolescents: a cross-sectional and longitudinal study. BMC Medicine, 10.1186/s12916-026-04658-6. Advance online publication. https://doi.org/10.1186/s12916-026-04658-6
• The IUNS ACTIVATOR project will analyse the gaps in nutrition research in Asia and how these gaps affect health policies
• The initiative aims to give a stronger voice to the Asian continent in scientific literature and to prepare it to face current nutritional challenges
A project led by the Institut de Recerca Biomèdica Catalunya Sud (Southern Catalonia Biomedical Research Institute – IRB CatSud, formerly IISPV) and Universitat Rovira i Virgili (URV) will assess the current situation of nutrition research in Asia, identifying the main gaps and needs in this field. This work is supported by a 5,000 dollar grant from the International Union of Nutritional Sciences (IUNS).
With this funding, the IUNS ACTIVATOR team will work over the next four years to evaluate nutrition research, reflect on how it matches regional priorities, and explore its impact on public health policies. The project will also focus on encouraging efforts to produce relevant scientific evidence at regional level, aiming to improve people’s health through mentoring and the involvement of key stakeholders.
“Carrying out this study is important because Asian countries are still underrepresented in global scientific literature. It is essential to identify their needs in the field of nutrition to understand whether research in Asia is ready to face its specific challenges, especially during a nutritional transition and the growing burden of non communicable diseases,” says Sangeetha Shyam, IISPV URV researcher, involved in the IUNS ACTIVATOR project: ‘Asian Decadal Nutrition Assessment, Reflection and Activation of Efforts for the Future’.
The project team includes 26 researchers from 13 countries in Asia and Europe, with expertise in nutrition, meta research and scientific communication. Another goal of the study is to involve young researchers to ensure the relevance and long term sustainability of the proposed solutions.
The project is supported by the Diputació de Tarragona, which has granted funding of 100,000 euros to carry out the initiative
The Pere Virgili Health Research Institute (IISPV) — which from 2026 will become the Southern Catalonia Biomedical Research Institute (IRB CatSud) — is leading the XISS project to integrate biomedical research and social innovation. The aim of the project is to transform the province’s healthcare system by creating effective connections between biomedical research, technological innovation, and citizen participation, with a direct impact on people’s health and well‑being. This initiative is carried out with the collaboration of the Diputació de Tarragona, which has provided a grant of €100,000 to support its development.
The project has enabled the preliminary studies for the creation of the Southern Catalonia Clinical Research Unit (UiC), which will be located at Sant Joan University Hospital in Reus and coordinated together with the three health regions (Camp de Tarragona, Terres de l’Ebre, and Baix Penedès). This infrastructure will make it possible to develop advanced clinical trials, including phase I oncology studies, as well as multicentre research on cardiovascular, metabolic, infectious, and neurodegenerative diseases.
The UiC will make it easier for patients from rural or geographically dispersed areas to take part in studies, reducing inequalities and increasing access to therapeutic innovation. In addition, data interoperability and the implementation of telemedicine services will ensure equal opportunities in access to clinical trials.
The project covers 184 municipalities and 10 counties in the province of Tarragona, involving local and socioeconomic stakeholders (city councils, hospitals, primary care centres, the university, civil society, patient associations, biotechnology and pharmaceutical companies, business clusters, and start‑ups).
Among the results already achieved are:
An analysis of the Spanish Clinical Studies Registry shows that the province of Tarragona has a much lower concentration of clinical trials than Barcelona (21.89 per million inhabitants compared to 114.89). The XISS project addresses this need by ensuring a more balanced distribution of resources and clinical research structures across Catalonia.
The XISS project positions itself as a national reference in translating scientific knowledge into clinical practice, promoting a healthcare system focused on people, the territory, and the reduction of social and geographical inequalities.
