Objective: To explore the formal and informal ways in which different actors involved in shaping trade agreements pursue their interests and understand the interactions with nutrition, in order to improve coherence between trade and nutrition policy goals. Design: The paper draws on empirical evidence from Australian key informant interviews that explore the underlying political dimensions of trade agreements that act as barriers or facilitators to getting nutrition objectives on trade agendas. Setting: Countries experiencing greater availability and access to diets full of energy-dense and nutrient-poor foods through increased imports, greater foreign direct investment and increasing constraints on national health policy space as a result of trade agreements. Participants: Interviews took place with Australian government officials, industry, public-interest non government organizations and academics. Results: The analysis reveals the formal and informal mechanisms and structures that different policy actors use both inside and outside trade negotiations to pursue their interests. The analysis also identifies the discourses used by the different actors, as they attempt to influence trade agreements in ways that support or undermine nutrition-related goals. Conclusions: Moving forward requires policy makers, researchers and health advocates to use various strategies including: reframing the role of trade agreements to include health outcomes; reforming the process to allow greater access and voice to health arguments and stakeholders; establishing cross-government partners through accountable committees; and building circles of consensus and coalitions of sympathetic public-interest actors.