This thesis aims to explore ‘how children are’ in a case study of Achuar communities of the mid Corrientes River region, in the Peruvian Amazon. An interdisciplinary approach, drawing on anthropological, epidemiological and sociological methodologies, is used to build a multi-dimensional analysis of relations between the physical and social context of the Corrientes River basin and young children’s ‘how-being’. Grounded in a focus on everyday practice in communities and health posts, this analysis highlights intersections and tensions in knowledge about and among inhabitants, interrogating tacit understandings of what it means for children to be ‘healthy’. Inter-related themes of place, food and work are explored using complementary theoretical tools from Said (strategic location and strategic formation), Bourdieu (relational analysis) and Amazonian anthropological theory of conviviality and perspectivism. A concept of ‘how-being’, developed to avoid the assumptions inherent in ‘health’ and ‘well-being’ is introduced and discussed.