Several studies have begun to determine the time course of events sensing energy availability in rodents. In contrast, there is not a single study that has examined this in humans to date. A better understanding of this energy sensing machinery in humans is of utmost importance to give us new insights into developing new therapies for common diseases such as obesity, diabetes mellitus, cardiovascular diseases and cancer. In these diseases, disturbances in the energy-sensing machinery possibly play a role. To determine the time course of energy sensing events in humans, the investigators will measure the concentration of various hormones in plasma, and biochemical changes in skeletal muscle at sequential time points during starvation in humans. The investigators choose to study the molecular machinery in muscle, since muscle is very sensitive to fuel deprivation.