Development programmes tackling severe acute malnutrition (SAM) in children tend to try to replace traditional beliefs with biomedical knowledge. However, stigmatization associated with undernutrition may be an additional impediment to seeking assistance. Drawing on the concepts of cognitive polyphasia and of othering, this study explored how different types of knowledge are used simultaneously in order to maintain a sense of otherness from the undernourished child in Nepal. A lexicometric analysis of answers to open-ended questions in a survey of villagers (N = 376) conducted in two Nepalese districts indicated three patterns of representations of children with SAM. The analysis revealed that cognitive polyphasia can take various forms (hybridization, selective prevalence or displacement), which both shape and are shaped by different ways of establishing otherness from the undernourished child. Taken together, these results allow a better understanding of the meaning of villagers' health advice regarding undernutrition and provide new avenues for implementing nutrition-related programmes. On a theoretical level, these results go beyond a simple statement of the plurality of knowledge, considering cognitive polyphasia as a relational outcome.