The goals for this fellowship are to develop and test the application of compartmental models to describe lipoprotein tracer data. This fellowship will focus on two problems. The first being the development of a compartmental model to describe the kinetics of apolipoprotein B (apoB) and triglyceride within the VLDL, IDL and LDL fractions of individuals with visceral obesity on eicosapentanoic acid and Atorvastatin (an HMGCoA reductase inhibitor) therapy. The novelty of this study involves the simultaneous use of tracers for the apoB and triglyceride moieties of the lipoprotein particles. The second problem will involve the development and testing of a compartmental model of chylomicron remnant metabolism using a breath test. Previous studies have used the Vitamin A protocol, the results of which are difficult to analyze. The goal of this project is to develop a model which will describe the rates of remnant catabolism following the infusion of labeled fatty acids.