Addressing the double burden of malnutrition in Peru: using a community-based system dynamics approach to improve food systems The Peruvian people suffer from what has been described as a "double burden" of malnutrition. This means that they simultaneously experience undernutrition and over-nutrition. Undernutrition includes inadequate intake of vitamins, low height for age, or low weight for height. Over-nutrition is the result of high consumption of unhealthy and processed foods, which are high in fat, sugar and salt, and includes overweight and obesity and other diet-related diseases such as diabetes and heart disease.   The way that food is produced, sold and consumed in the country ("the food system") is a major driver of this problem. While Peru has undertaken some bold actions to address malnutrition over the past two decades most policies have a one-sided focus, targeting either under or over-nutrition and fail to address both aspects. The process of identifying and evaluating policies to address this problem needs to take into account the complex economic, social, and cultural factors that influence food systems.  We will use innovative research methods to identify drivers of the double burden of malnutrition in Peru and potential policy solutions which take these complex factors into account. The specific objectives of this project are: 1. Map the drivers of the food system that contribute to the double burden of malnutrition in three diverse regions in Peru; 2. Identify policies and interventions that would address the double burden of malnutrition through changes in the food system; 3. Quantify the impacts of identified policies and interventions on the double burden of malnutrition; 4. Prioritise identified policies and interventions and actively disseminate recommendations   Our research project is characterised by the active involvement of members of the community throughout all its stages. The projects starts with workshops in three regions of Peru (Lima, Tumbes and Huancavelica) during which our research team will guide small groups of community stakeholders to conceptualise and map the drivers of the food system that contribute to the double burden of malnutrition. Community stakeholders will include lay members of the community, policymakers at local and national government authorities, and academics, with a deep understanding of the community issues and experiences, either as residents or organisers, leaders, and service providers. At the next stages of the project, stakeholders will guide the research team to identify relevant policy options that are appropriate at national and regional level. They will also be consulted throughout the quantitative evaluation of these policies to ensure that it accurately represents stakeholder views as expressed during the workshops. Finally, they will have an active role in prioritising and recommending appropriate policy options, disseminating the results of the project to other members of the community, and acting towards policy change.  Our research project is a collaboration between universities in Peru, the United Kingdom and Brazil. The research team have expertise in policy evaluation, food systems and public heath nutrition, modelling and health economics. The project will strengthen academic collaboration between these institutions and build research capacity in Peru. It will also strengthen collaboration between Peruvian institutions and members of the local community by establishing long-term working relationships between parties. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.