This module will provide an intensive review of the metabolic pathways involved in lipid and lipoprotein homeostasis. The focus will be on molecular mechanisms involved in regulation of lipid biosynthesis (cholesterol, fatty acids, and triglyceride) in the liver, adipose tissue, and intestine. Metabolic pathways involved in lipid mobilization and lipoprotein biosynthesis will be reviewed including nutritional and hormonal regulatory networks. Finally, mechanisms leading to dysregulation of lipid and lipoprotein metabolism in obesity, metabolic syndrome, and diabetes will be discussed highlighting the critical role of lipid dysregulation in the current epidemic of human obesity, insulin resistance, and type 2 diabetes.