How Hormonal Status affects the bmr?
Thyroid status may be most important factor and can make differences of up to plus or minus 50% for hyperthyroidism or hypothyroidism, respectively. Hyperthyroidism increases the resting metabolic rate, whereas hypothyroidism decreases the RMR. Stimulation of the sympathetic nervous system (e.g. during the period of stress or emotional excitement or fear, anxiety) causes the release of epinephrine, which directly promotes glycogenolysis and increases cellulas activity. This too is associated with increased metabolic rate. In adult premenopausal women, the metabolic rate fluctuates with the menstrual cycle. An average of 359 Kcal/ day difference in the BMR has beet] measured between the low point, about 1 week before ovulation on day 14, and the high point, just before the onset of menstruation.