PROJECT SUMMARY/ABSTRACT - CLINICAL SCIENCE RESEARCH CORE The Clinical Science Research Core (CSRC) enhances and facilitates leading-edge clinical and translational nutrition/obesity research through the operation of two distinct but interactive sub-cores that provide an array of services and unique training through a cohesive, “one-stop” organizational structure that ensures optimal integration of high-quality services and training. The Clinical Studies Performance sub-core assists investigators by: i) providing consultation in designing a clinical research study and in interpreting the results of the data generated by core analyses, ii) providing biostatistical support to determine adequate sample size and appropriate statistical analysis, iii) measuring body composition and energy expenditure, iv) developing and preparing study protocol-specific meals for metabolic testing and take-out meals for diet intervention studies, v) preparing stable isotopically labeled metabolic tracer and hormone infusates to assess metabolic function, vi) providing high-quality, clinical laboratory tests used to determine participant eligibility, monitor participants during interventions, and evaluate metabolic functions, vii) obtaining muscle and adipose tissue biopsy samples and inserting radial artery catheters for blood sampling, viii) evaluating cardiovascular function, ix) performing exercise and physical performance testing, x) providing inpatient and outpatient sleep monitoring services, xi) providing assistance in implementing lifestyle interventions (diet manipulation, weight loss/weight gain, exercise training); and xii) providing training in specific procedures to aid investigators in the performance of clinical studies. The Metabolic Kinetics sub-core assists investigators by: i) providing consultation in designing protocols to evaluate metabolic kinetics (e.g., the hyperinsulinemic-euglycemic clamp procedure and frequently sampled intravenous glucose tolerance test in conjunction with stable isotopically-labeled tracer infusions to evaluate whole-body and tissue- -cell function) and in interpreting the results of the data generated by core analyses, ii) mass-spectrometry analysis of biospecimens to determine tracer enrichment in metabolic substrates and macromolecules, iii) mathematical modeling of tracer and non-tracer data to assess metabolic kinetics, and iv) providing education and training in specific analyses. The Metabolic Kinetics sub- core has a long tradition of providing these services and in the past has focused its sample analysis and modeling on specific metabolites to evaluate specific metabolic pathways (e.g., adipose tissue triglyceride lipolytic rate, hepatic glucose production rate, VLDL-triglyceride and apolipoprotein B-100 production rate). The core has now expanded these services to include the new and rapidly evolving discipline of dynamic metabolomics, which makes it possible to evaluate metabolite flux through entire metabolic...