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Since pregnant or breastfeeding women have extra nutritional needs, does that mean they have a higher BMR?
Why I thought the conclusion would be sensible: Since BMR is the energy needed to perform body functions (breathing, respiration, homeostasis, digestion, etc), pregnant woman or breastfeeding women, because of their extra 'activity' (due to the presence of the fetus) will have a higher BMR.
Basal metabolic rate for a particular organism is determined by the amount of calories that the organism needs for basal metabolic processes (i.e. basal energy demands). Since pregnant and breastfeeding women have increased caloric requirements (i.e. increased energy demands), then that means by definition their basal metabolic rate is increased.
A pregnant woman’s total energy expenditure during pregnancy is mainly because of a raised basal metabolic rate, or BMR. The energy necessity of basal metabolism is influenced by nutrition prior to pregnancy and the size of the fetus. According to a 1990 study, “Energy cost of physical activity throughout pregnancy and the first year postpartum in Dutch women with sedentary lifestyles” by Joop MA van Raaij, et al, “BMR is increasing throughout pregnancy mainly because of fetal demands.” BMR will decrease to preserve energy if maternal energy stores are too low when a woman becomes pregnant. Also, women having larger babies tend to have greater increases in their BMR and greater decreases in the rate of their energy stores than pregnant women having normal-weight or underweight babies.
