The conceptual model for the Harvard TREC research projects is summarized below. This multilevel model posits that macro-level and energetic factors influence cancer risk and survival through multiple interrelated pathways, with cancer-related biomarkers (insulin/IGF components, sex hormones, and adipokines) at the fulcrum point in energy balance and cancer pathophysiology. As a whole, the four projects will address how genetic, behavioral, and structural factors influence obesity and the biologic mediators between obesity and cancer at multiple stages of life (infants, adolescents, healthy adults and cancer survivors), how these determinants interact with each other, and, ultimately, whether these biologic mediators influence cancer survival and are modifiable among cancer survivors. The proposed projects also use a variety of research strategies including the combination of qualitative and quantitative methodologies in a contextual study, observational studies, behavioral and pharmacological interventions, and multilevel research to address the multiple levels of influence that genetic factors, circulating biomarkers, anthropometry, diet, behavioral factors, the social environment, and the built environment have on the proposed disease outcomes, their mediating effects, and interactions. Each project will address both overlapping and distinct pieces of the puzzle of the determinants of obesity and the links between obesity and cancer risk and survival.