Malnutrition remains very frequent in hospital and particularly in intensive care settings. In our country we do not have data about malnutrition on the critically ill patients, and the impact of malnutrition on their clinical outcome. Despite knowledge for the benefits of providing nutrition support, the actual nutrition support received by patients in the intensive care unit (ICU) is not always optimal for various reasons. There is a growing need to adjust clinical practice to improve the quality of care in ICU, as well as conserve medical resources. Before we can efficiently improve practice related to nutrition support, it is important that we define what is actually being done, and how it affects the clinical outcome. Exploring the nutritional aspects of critically ill patients, this book could provide a basis for the development of new policies to improve patient care and decrease the cost of ICU treatment, especially in the conditions of our country and other poor countries, where healthcare resources are constrained.