Inclusion Criteria:  Adult (18-65 years of age) men and women  Exclusion Criteria:  Subjects with a history of any illness, other than obesity, that may affect insulin sensitivity (anemia, infectious diseases, renal or hepatic failure, uncontrolled hypertension, cancer, lymphoma, chronic inflammatory conditions such as inflammatory bowel disease and rheumatoid arthritis, states of cortisol or growth hormone excess, alcoholism or drug abuse, and eating disorders). History of diabetes mellitus. Subjects taking any medications that are known to influence glucose metabolism such as glucocorticoids will also be excluded. We will screen for these conditions by means of a detailed history and review of systems and physical examination (see below). Subjects taking any medications known to affect lipids such as statins will also be excluded. We will screen for these similar to above. Cholesterol greater or equal to 250 mg/dL and/or triglyceride levels greater than 500 mg/dL at the time of screening, as determined by laboratory testing. Subjects who have a known history of anaphylaxis or anaphylactoid-like reactions or who have a known hypersensitivity to anesthetic agents such as Lidocaine or Marcaine will be excluded from the study. Hypersensitivity to fat emulsion or any component of the formulation; severe egg or legume (soybean) allergies; pathologic hyperlipidemia, lipoid nephrosis, acute pancreatitis associated with hyperlipemia. Hypersensitivity to heparin or any component of the formulation Severe thrombocytopenia, uncontrolled active bleeding, disseminated intravascular coagulation (DIC); suspected intracranial hemorrhage. Subjects with a history of bleeding dyscrasia, poor wound healing or any medical condition precluding supine position will be excluded from the study. Unable to follow study protocol or any condition that in the opinion of the investigator makes the subject unsuitable for the study. Pregnancy