These lecture notes on human metabolism are intended for classroom teaching at the advanced undergraduate level. They should also be suitable for self-study if the reader is familiar with basic biochemical concepts, such as those taught in first or second year undergraduate courses. While these notes focus on metabolic pathways and biochemical mechanisms, they also relate these to medical problems, such as for example the pathogenesis of diabetes and of atherosclerosis. They should thus be of interest to students and readers from medicine and health sciences.