So far, the anthropology of global health has mostly focused on biosecurity, disaster relief, HIV and other infectious and tropical diseases, sexual reproductive health, and clinical trials. Anthropological investigation of health experts’ growing concern for sustainability and noncommunicable disease requires a different theoretical approach than that focused on immediate infections and disasters. By attending to how linkages are made between biological and planetary health, crisis and chronicity, and fetal and global development, the project will help to develop this approach, while also generating valuable knowledge about transforming techniques of health governance. What is new about the research is that it attends to the fact that global health experts promoting the first 1000 days intervention are aware of this, and are thus actively working to coordinate across differences in geography, discipline, and timescale. Anthropologists have classically embraced holism as our value, critiquing health professionals as overly reductionist). Careful study of the global health community’s engagement with holism will generate insight into how holistic ambitions are implemented in practice, while also cultivating alternative pathways for anthropology to relate to global health other than through criticism. The project’s multi-sited approach is another important innovation. While valuable site-based work on the first 1000 days intervention has been carried out by anthropologists, comparative research across national sites has not yet been conducted. It conducts research across diverse sites to have empirically rich material for analysis—not to lay claim to a general, global truth. Moreover, the innovative technique of “contrasting” that this study adopts does not seek to compare static or distinct objects but to study the first 1000 days intervention as it circulates and transforms, taking up the challenge of comparing relational and transforming objects. This theorization will help to bridge two longstanding anthropological concerns: that of alterity, and that of travel and transition. The aim is to examine the meeting of differences in a way that does not pin these differences down. Anthropological analyses of the meeting of biology with governance have typically sought to describe broad, pervasive patterns; the ethnographer’s job was to accumulate local knowledge to shed light on phenomena occurring at global scale. Theories of bio-medicine, bio-politics, bio-security, bio-capital, and bio-power that were important for the field of anthropology in the late 20th and early 21st centuries were predicated upon the global stability of the relation between “the biological” and the medicine, politics, security, capital, and power to which biology was linked. Yet as ethnographers have begun to systematically carry out comparative work on global interventions, the heterogeneity of biology, medicine, politics, security, capital and power – as well as the heterogeneity of their relations – has become increasingly apparent.That “conceptual objects” do not easily hold stable across time and space raises important questions about how anthropological theories change as they travel, and how we might attend to these changes in our own practices of theorization. The project will reflect upon the “social lives” of theory in light of the intervention’s adaptability to better attune anthropological practices of theory-making to the contingencies of socio-material processes. Finally, the project’s focus on the adaptability of global concern for the first 1000 days will have highly promising implications for the design of health interventions.