BMR full form
Basal Metabolic Rate
BMR full form is Basal Metabolic Rate. Basal metabolic rate (BMR) is the amount of energy (in calories) that a person needs to maintain their body weight in a resting state. This includes the energy needed to keep the heart beating, the lungs breathing, and the brain functioning. It does not include the energy needed for physical activity or digestion.
BMR is measured under very restrictive circumstances while the person lies down quietly for about an hour, usually in a darkened room. The body temperature is also taken at this time.
When doing BMR measurements it is important to do so on an empty stomach and not drink caffeine or smoke during testing because these factors can increase one’s energy needs by as much as 20%.
How does one determine basal metabolic rate? Each individual has different calorie requirements depending on their gender, age, weight, muscle mass, body surface area, and level of daily physical activity. Here are some estimates of calorie requirements based upon general information:
An adult man requires approximately 18 calories per pound per day; whereas, an adult woman requires approximately 15 calories per pound per day. This means that a man weighing 154 pounds would require approximately 2700 calories per day to maintain his weight, whereas, a woman of the same weight would require approximately 2200 calories per day.
The most accurate way to determine one’s BMR is by having it measured in a laboratory while staying in an enclosed chamber where all energy expended is measured. This test can be done overnight or for several days if more information is needed.
However, this does not mean that anyone who wants to know their BMR can’t estimate it using some very simple calculations. There are many sites on the internet that use various formulas to calculate a basal metabolic rate.
One of the most recognized equations was developed by Harris-Benedict and published in 1919. It takes into account a person’s age, weight, height, and gender to estimate BMR.
Many variations of the Harris-Benedict equation have been developed over the years but many use it as a standard. The Mifflin St Jeor equation is another one that has been very popular for calculating the basal metabolic rate. This equation was developed by Mifflin et al in 1990 and takes into account height, weight, age, and sex:
BMR = (10 x weight) + (6.25 x height) – (5 x age) – 5
Older equations such as those developed by Henry & Rees and Forbes & Hong take into account only height, weight, and age. The Katch McArdle formula is also known as the Cunningham formula is based on lean body mass instead of total body weight.
Many formulas have been developed to estimate calorie requirements for physically active people who engage in strength training, endurance sports, or are involved in heavy manual labor. These equations take into account the person’s BMR, daily activity factor, and additional energy required for physical activity:
Harris-Benedict equation + (physical activity factor x calories expended)
Mifflin St Jeor equation + (physical activity factor x calories expended)
Katch McArdle formula
BMR multiplier = 1.2 – (0.1 x wt in kg)
BMR multiplier = 1.3 -(0.1 x ht in cm)
A quick and easy way to estimate your BMR, daily calorie needs, and total calories burned is by using the Katch McArdle formula as follows:
If you weight 154 pounds (70 kg) then your lean body mass is approximately 70 kilograms (154 lb / 2.2 = 70kg).
Your Lean Body Mass (LBM) in kilograms = weight in pounds / 2.2
To determine TDEE multiply LBM x applicable activity multiplier:
LBM X 1.3=TDEE
TDEE= 70 kg x 1.3= 91 kcal/day + (91 x 24 hours = 2040 kcal/day)
Your approximate TDEE would be 2100 calories per day.