Total Energy Expenditure and its Components

It is customary to consider energy expenditure as being made up of three components: the energy spent for basal metabolism (or basal metabolic rate), the energy spent on physical activity, and the increase in resting energy expenditure in response to a variety of stimuli (in particular food, cold, stress, and drugs). These three components are depicted in Figure 4.

Basal Metabolic Rate (BMR) or Resting Metabolic Rate (RMR)

This is the largest component of energy expenditure accounting for between half to three-quarters of daily energy expenditure. It is measured under standardized conditions, i.e., in an awake subject lying in the supine position, in a state of physical and mental rest in a comfortable warm environment, and in the morning in the postabsorptive state, usually 10-12 h after the last meal. There is an arbitrary distinction between RMR and BMR in the literature. RMR may be considered equivalent to BMR if the measurements are made in postabsorptive conditions. It seems difficult to partition RMR into various subcomponents since the metabolic rates of individual organs and tissues are hard to assess in humans under noninvasive experimental conditions. BMR can vary up to ±10% between individuals of the same age, gender, body weight, and fat-free mass (FFM), suggesting that genetic factors are also important. Day-to-day intraindividual variability in BMR is low in men (coefficient of variation of 1-3%) but is greater in women because the menstrual cycle affects BMR. In both women and men, sleeping metabolic rate is lower than BMR by

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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