The increase in body weight in combination with fetal weight or with the increased levels of concentration of IGF-I in serum explains approximately 60% of the variability in the increase in BMR of pregnant women.

The total energy cost of pregnancy is largely due to an increased basal metabolic rate (BMR). Pregnancy- BMR increases when a woman is pregnant. Genetic factors are also responsible for heredity which affects the BMR. Genes do have a large influence on weight because of DNA and cell protein synthesis which controls the metabolism level. This difference is because of the fact that men have greater muscularity and lean body mass( lower percentage of adipose tissue) than women. Girls show the pre puberty rise two years earlier than boys and when boys reach puberty stage their basal energy expenditure is higher than girls and continues to be higher throughout the life. Genetics and hormones: On the onset of adolescence, there is a difference in the basal heat production for males and females. The changes in BMR is different for children and adults because adults are more susceptible to the changes in the environment, whereas children are always kept protected from the environmental changes. After puberty, the BMR gradually keeps on decreasing. It keeps on gradually decreasing until the period of early adolescence (12-15 years of age). The child reaches the peak of basal heat production at two years of age. The new-born’s basal metabolism rate increases rapidly in proportion to the rate of growth and development of their muscles during the life span of one year. Age is a factor that has a major significance in human nutrition and diet. Basal metabolic rate is dependent on body size as it is indicated by weight, age, gender. As the muscle mass increases, body consumes more amount of energy to maintain and control its basic everyday functions, this giving BMR a well-deserved boost in the metabolic activity.Īge: The basal metabolic rate decreases linearly with increase in age number. Anything that reduces lean mass will result in reduction of BMR. And that instant energy is released through muscle activity. Muscle mass: BMR is largely determined by the total body lean mass as lean mass requires a lot of energy to perform energetic activities. Male: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years) The general formula for calculating BMR in female and male is:įemale: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years) On the other hand, overweight or obesity, Cushing’s syndrome, anorexia, adrenal insufficiency and immobilization decreases BMR. These diseases are meant to increase BMR.

BMR is also altered by various clinical conditions such as viral fever, pregnancy, drugs, cancer, cholesterol, congestive heart failure, polycythaemia and Paget’s disease of the bone. Most of the hyperthyroid patients hold a BMR percent of positive 20% or more and hypothyroid patients have a BMR of negative 20% or less. Normal BMR percentage ranges from negative 15% to positive 5%. High values suggest that there exists presence of thyrotoxicosis. Low values in the results suggest that there is hypothyroidism. The test indirectly measures metabolic energy expenditure or the level of heat production.

Since, the standard equipment for the measurement and calculation of BMR might not be readily available, the BMR can be easily estimated and measured from the oxygen consumed over a period of time by analysing the samples of expired air. It measures the oxygen consumption rate under basal conditions of overnight fast and rest from mental and physical activity. One of them is through the evaluation of thyroid function. There are various methods to measure BMR. The rest is all used in basal metabolism, that is, the energy that we require in a resting state, for the body to perform functions such as blood circulation, digestion, and breathing. Nearly 20 percent of the energy we take is used for brain functioning and metabolism. Energy in BMR includes energy that is used for normal body activities like cellular homeostasis, muscular activities, cardiac function, nerve function. BMR is responsible for approximately 60% of the energy expenditure on a day to day basis.

Bmr calculator kg cm