This article introduces the notion of ‘translational competency’, a skill of attending to different understandings of health and how these are negotiated between medical settings and everyday life. This skill is especially important for the design of obesity-prevention policies and programs, given the diverse values surrounding both healthy eating and desirable weight. Through its focus on communicative interactions, translational competency entails a refusal to treat cultural differences regarding diet or body size as a problem. Rather, it encourages engagement with the relational contexts out of which health problems develop and transform, taking culture to be a process of negotiation and adaptation. In this article I present an example of the utility of the skill of translational competency taken from research on obesity in Guatemala. I then illustrate how translational competency might be used in the design of obesity interventions.