Patients undergoing major surgery, trauma or burns are prone to develop an exacerbated inflammatory response, which is potentially lethal to the individual. Recently, the researchers' group showed in a rodent model of hemorrhagic shock that high-fat feeding administered before shock attenuates inflammation and reduces intestinal and hepatic damage. In the mechanism that underlies this protective effect, the release of cholecystokinin in gut wall and activation of efferent vagus bundles are crucial events. Before investigating the effect of high-fat nutrition in clinical setting, suitable markers of inflammation and organ damage need to be selected. In this study, blood will be collected in patients undergoing different types of operations. Consequently several markers for inflammation and organ damage will be determined. Hence, suitable parameters for a future high-fat intervention study will be selected.