[Malnutrition and evaluation of the nutritional status].

Malnutrición is assessed from its concept to the main causes thereof. The different types and degrees of malnutrition are described as well as their clinical presentation. The prevalence of malnutrition is defined, how this affects both the hospitalized and the non-hospitalized population, and the factors that contribute to the variability of the results of the prevalence thereof. The objectives of the nutritional assessment are analyzed, as were the requirements that should be met by the ideal nutritional marker, and the different nutritional markers used. Among these are the classic anthropometric measurements all the way up to the serum proteins or the immunological parameters. The nutritional indexes that allow an assessment of the existence of a risk for the developing malnutrition are described also. A special emphasis is made on the assessment of the clinical history from the nutritional point of view, on the subjective global assessment, and on dietary questionnaires. The role of the muscle function as a nutritional marker is also analyzed, as well as the possibility of using other methods of body composition assessment. The importance of establishing special considerations in view of the collectives to be analyzed is notable. Finally, the clinical and economic consequences of malnutrition are analyzed.