Increasing evidence shows that undernutrition and overweight/obesity co-exist, affecting countries, households, and individuals. This phenomenon has been labelled the ‘double burden of malnutrition’ (DBM). It has been recognised as a public health problem in Sub-Saharan Africa, calling for interventions addressing all forms of malnutrition simultaneously. Despite impressive progress in reducing undernutrition, Ethiopia still has one of the highest rates of undernutrition 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 and children under five) will assess the DBM to develop a roadmap for action to tackle multiple forms of malnutrition. For this, a 4P cycle (Problem, Policies/Programmes, People, Priority) was assessed. The exploration of each ‘P’ constituted a work package, utilising a range of methodologies. The DBM is multifaceted and complex, as such an interdisciplinary approach is fundamental to tackling it. The TAMMIE project is therefore interdisciplinary, drawing on insights from different disciplines (e.g. epidemiology, nutrition, public health, policy science, social sciences) and methodologies (e.g. systematic review, photovoice, social network analysis, multi-criteria mapping). The gender sensitive approach of this project is key, as women are agents of change and are central to promoting healthy diets and preventing multiple forms of malnutrition for themselves and their offspring.