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

Basal Metabolic Rate

Total Energy Expenditure:

Here are the different types of total energy expenditure that an individual consumes on daily basis;

·         Basal energy expenditure

·         Basal metabolic rate

·         Resting metabolic rate

Basal Energy Expenditure (BEE):

Also called basal metabolic rate, or BMR.

This is the energy needed to carry out fundamental metabolic functions, such as breathing, ion transport, normal turnover of enzymes and other body components, etc.

Basal energy expenditure (BEE) can be simply defined as the minimum amount of energy expended that is compatible with life. A person's BEE reflects the amount of energy used over 24 hours while physically (i.e., lying down) and mentally.

Basal Metabolic rate

Basal metabolic rate (BMR) measurements are made;

•       Early in the morning, before the person has engaged in any

•       Physical activity and l0 to 12 hours after the ingestion of

•       Any food, drink, or nicotine

.

What is the normal basal metabolic rate?

The average basal energy expenditure (BEE), also known as basal metabolic rate(BMR), for American women is about 1,400 calories while for a man its roughly 1,800. But don't assume you're average!

What is considered a high BMR?

While you and I say "fast metabolism," scientists use the phrase high "basal metabolic rate," or the amount of calories the body needs while resting. The misconception is that thin people always have a high basal metabolic rate. It is true that muscle requires more calories than fat.

How BMR is calculated?

The Harris Benedict Equation determines your total daily energy expenditure (calories). The BMR formula uses the variables of height, weight, age and gender tocalculate the Basal Metabolic Rate (BMR). ... The Harris Benedict Equation is a formula that uses your BMR and then applies an activity factor.

Causes of individual differences in BMR:

The basal metabolic rate varies between individuals. One study of 150 adults representative of the population in Scotland reported basal metabolic rates from as low as 1027 kcal per day (4301 kJ/day) to as high as 2499 kcal/day (10455 kJ/day); with a mean BMR of 1500 kcal/day (6279 kJ/day). Statistically, the researchers calculated that 62.3% of this variation was explained by differences in fat free mass. Other factors explaining the variation included fat mass (6.7%), age (1.7%), and experimental error including within-subject difference (2%). The rest of the variation (26.7%) was unexplained. This remaining difference was not explained by sex nor by differing tissue size of highly energetic organs such as the brain.

Differences in BMR have been observed when comparing subjects with the same lean body mass. In one study, when comparing individuals with the same lean body mass, the top 5% of BMRs are 28-32% higher than the lowest 5% BMR. Additionally, this study reports a case where two individuals with the same lean body mass of 43 kg had BMRs of 1075 kcal/day (4.5 MJ/day) and 1790 kcal/day (7.5 MJ/day). This difference of 715 kcal/day (67%) is equivalent to one of the individuals completing a 10 kilometer run every day. However, this study did not account for the sex, height, fasting-state, or body fat percentage of the subjects.

Energy Expenditure Breakdown
Liver	27%
Brain	19%
Skeletal Muscles	18%
Kidney	10%
Heart	7%
Other Organ	19%

Resting Metabolic Rate:

Resting metabolism is the energy required by your body to perform the most basic functions when your body is atrest. ... Your basal metabolic rate (BMR) is the total number of calories your body burns at rest. You can calculate your resting metabolic rate to find out your personal number.

•      If any of the conditions for the

•      BMR are not met, energy expenditure should be referred to as the resting metabolic rate (RMR). For practical reasons

•      The BMR is now rarely measured. RMR measurements are used in its place, which in most cases are higher than the

•      BMR by 10% to 20%

BMR is most accurately measured in a lab setting under very restrictive conditions. Definition of Resting Metabolic Rate. A measurement of the number of calories that your body burns at rest. Resting metabolic rate is usually measured in the morning before you eat or exercise and after a full night of restful sleep.

What is the average resting metabolic rate?

Your basal metabolic rate (BMR) is an estimate of the number of calories you body uses in a day, at rest. ... For women, the average BMR in the United States is 1,493 calories. For men, the average BMR in the United States is 1,662 calories.

Is RMR higher than BMR?

BMR is synonymous with Basal Energy Expenditure or BEE. BMR measurements are typically taken in a darkened room upon waking after 8 hours of sleep, 12 hours of fasting to ensure that the digestive system is inactive, and with the subject resting in a reclined position. RMR can be defined as Resting Metabolic Rate.

Change in RMR with increasing Age: