Fatores que afetam o metabolismo basal: uma revisão de literatura

Abstract

Basal metabolic rate (BMR) measures oxygen consumption under basal conditions of overnight fasting and rest from physical and mental efforts. BMR can be influenced by characteristics inherent to the individual, such as body size and composition, age, physical activity, diet, as well as non-controllable variables such as weather. The aim of the present study was to carry out a descriptive literature review on several variables that can influence the basal metabolic rate. It was found that body mass has a high correlation with BMR following the Law of Body Surface, where heat production is constant per unit of body surface. Thus, animals of varying sizes would have the same heat production per unit of body surface area. The decline in BMR with age seems to be mainly a reflection of changes in body composition that occur with aging, such as an increase in sarcopenia and an increase in the percentage of body fat. As for the practice of physical activity, it is understood that the practice of regular physical activity can increase the BMR as a result of the adaptation to exercise, considering that there is a positive correlation between the BMR and the maximum oxygen consumption. In the diet, it was verified that the digestion, absorption and storage of the ingested nutrients, mainly the protein, causes the process of thermogenesis induced by the diet or the thermic effect of the foods, which exerts a direct influence with the TMB. In addition to these, external variables such as climate, however, for reasons not very well understood. Adequate knowledge of controllable and non-controllable variables should receive considerable attention, as their correct manipulation can make a total difference in the prescription of physical exercises, with emphasis both on competition and for health promotion.