•Determined from the consumption of oxygen and excretion of carbon dioxide and urinary nitrogen, or from the heat production of the animal. Body size is a major factor in TEE and hence BMR.
•BMR is calculated using the body weight in kg/surface area in meters.
•The use of surface area of the body enables comparison of measurements of BMR in individuals of different size.
•The surface area is calculated from height and weight using monograms (DuBois height-weight chart).
•BMR is more closely related to lean body mass than to surface area.
•The surface area of the individual can be determined from weight and height data according to the formula of DuBois:
Area (cm2) = weight (kg) 0.425 x height (cm) 0.725 x 71.84
•Given the oxygen consumption during specific time and the height-weight data, the individual’s BMR can thus be obtained in terms of calories generated per square meter of body surface per hour.
•The BMR is subject to variation by a number of physiological and pathological conditions.
•A simple approach to calculate BMR is to use values of 1.0 and 0.9 kcal/hr/kg body weight for men and women, respectively. When calculated over 24 hr, this results in values of 1680 and 1173 kcal for an average 70 kg man or 58 kg woman, respectively.
•More accurate values are obtained with the formulas.
No comments:
Post a Comment