The goal of this proposal is to develop a novel triple-tracer positron emission tomography (PET) method to image in vivo insulin-stimulated tissue perfusion, glucose transport and glucose phosphorylation in skeletal muscle in healthy individuals. The long term goal will be to later apply this model to the study of metabolic diseases, notably type 2 diabetes mellitus (Type 2 DM) and obesity (Ob). While it is often suggested that glucose transport is the rate-controlling step for insulin action, we will test the hypothesis that the control insulin exerts on the uptake of glucose into skeletal muscle is distributed across flow and tissue perfusion, trans-membrane transport and intra-cellular phosphorylation of glucose.