Resting energy expenditure; assessment methods and applications.

UNLABELLED The energetic expense daily total of an individual (EEDT) represents the energy that the organism consumes. It is constituted by the sum of: metabolic basal rate (MBR), termogenesis endogenous (TE) and energetic expense linked to the physical activity (EEPA). The determination of the EEDT considering the physical activity and the state of health of a person, it is very important to fit the calculation of the nutritional need for every individual. The MBR is the minimal quantity of energy that an organism needs to be alive. It constitutes a from 60 to 70 % of the EEPA in the majority of the sedentary adults, while, in the physically very active individuals it is of approximately 50 %. It changes depending on the corporal composition, specially on the corporal lean mass. The basal metabolism expressed as MRB, it is different from the metabolic rate in rest (MRR) or Resting energy expenditure (REE); the latter is obtained when the determination is done in rest and in the conditions described for the MRB but not in fasting, including therefore the energy used for the biological utilization of the food. Habitually, the REE decides by means of different technologies as the indirect calorimetry, the electrical bioimpedancy, the doubly marked water, the predictive equations, between others. These methods are used in the clinical practice and in scientific studies. Nevertheless, due to the inconsistency of the results of these researches, still there is no a consensus with regard to his applicability though the evidence indicates that the measurement of the consumption of oxygen, it is the method of major precision. AIMS This review has as aim expose the components of the energetic expense in rest, as well as the technologies for its determination and estimation, indicating its advantages, limitations and practical applications. RESULTS Part of the technologies of evaluation of the energetic expense described in this review, they remain relegated, for its complexity and cost to the area of the investigation. For a long time the indirect calorimetry, she remained also restricted to this field. Nevertheless, the technological advances have allowed the development of precise light and attainable equipments that allow that at present it should be a very useful method in the clinical space of the determination of the REE.