Two investigational drugs (not approved by the Food and Drug Administration) for the treatment of high lipid levels or insulin resistance are being examined in this study: one drug is called tauroursodeoxycholic acid (TUDCA), the other is called sodium phenylbutyrate (PBA). This study is designed to test if TUDCA and/or PBA is effective in people who are obese with insulin resistance and high lipids. We hypothesize that pharmacologically-induced decreases in ER stress will improve insulin action and hepatic lipid metabolism in obese subjects.