Increasing evidence shows that undernutrition and overweight/obesity co-exist, affecting countries, households, and individuals, a phenomenon known as the ‘double burden of malnutrition’ (DBM). It has been recognised as a public health problem in Sub-Saharan Africa, requiring double-duty actions (DDAs) – interventions addressing all forms of malnutrition simultaneously. Despite impressive progress in reducing undernutrition, Ethiopia still has one of the highest rates globally, which coincides with a rising problem of overweight/obesity, particularly in urban areas. Nevertheless, funding for interventions remains focused on undernutrition. Shifting policies and programmes to address multiple forms of malnutrition requires a good understanding of the problem, the current policy/programme environment, and stakeholders’ views on the nature of the problem and potential ways of addressing it. Unfortunately, such evidence is scarce. Therefore, the TAMMIE project (TAckling Multiple forms of Malnutrition In Ethiopia amongst women of reproductive age (WRA) and children under five (U5)) assessed the DBM to develop an intersectoral roadmap for action to tackle multiple forms of malnutrition. For this, a 4P cycle (Problem, Policies/Programmes, People, Priority) was used, with each ‘P’ constituting a distinct work package. The DBM is multifaceted and complex, so an interdisciplinary and mixed-method approach was used, drawing on insights from diverse disciplines (e.g. epidemiology, nutrition, public health, social sciences, and policy science) and methodologies (e.g. systematic review, Photovoice, social network analysis, and multi-criteria mapping). The specific research objectives (RO) are listed hereafter: RO1: To synthesise quantitative evidence on the shared drivers of the DBM in low- and middle-income countries (LMICs) and qualitative evidence on the drivers of unhealthy diets in Ethiopia; RO2: To collate evidence on the content of policies/programmes and the enabling environment (i.e. the environment that helps policy development and implementation) that aim to address different forms of malnutrition in Ethiopia; RO3: To map out the key people and organisations who are involved in these policies and programmes; and RO4: To gather perceptions of diverse stakeholders on priorities, gaps, and opportunities to prevent the DBM in Ethiopia.