BMR-Basal Metabolic Rate
Basal Metabolic Rate (BMR) can be explained as minimum amount of calories required to sustain the body’s
functions and processes, when the body rests. It is responsible for consumption of about 70% of total calories used
up by the body. BMR is regulated by a hormone called thyroxin. This hormone is produced by thyroid gland, which
helps to control the body’s metabolic activities. Thyroxin affects the heart rate, body weight, muscle strength and
blood cholesterol levels.
BMR generally decreases with age. BMR is affected by certain body functions such as respiration, circulation and
maintenance of constant body temperature. Exercise, calorie consumption and lean body tissue can also affect this
rate. Body weight, height and environmental temperature also play a significant role in increasing the BMR. If BMR is
increased, then there would be constant calorie consumption. It results in burning excess fats and remarkable weight
loss. Increase in BMR offers a number of health benefits such as reducing the risk of developing heart disease,
stroke, heart attack and diabetes. An average BMR for adults ranges between 1200 and 1800 kcal.
Determination of BMR
BMR determines the overall metabolic rate and calories required to lose, gain or maintain the body weight. BMR is
determined using some genetic and environmental factors.
Genetics: Some people are born with higher metabolism rate, while some have slow metabolism.
Age: BMR generally decreases with age. After 20 years, it reduces about 2% every decade.
Gender: Men have a lower body fat percentage and a greater muscle mass. As a result, they have a higher BMR.
Body Surface Area: Your height and weight contribute a lot in determining BMR. The greater is your body surface
area, the higher is your BMR. Thin, tall people have a higher BMR.
Weight: If your body weight is more, then your BMR would be higher. The metabolic rate of obese women is about
25% higher than the metabolic rate of slim women.
Body Fat Percentage: If the body fat percentage is lower, then BMR will be higher. Generally men have lower body
fat percentage and hence, they have 10-15% higher BMR than women.
Body Temperature: With an increase of 0.5 C in the internal body temperature, BMR increases by about 7%. The
chemical reactions in the body take place more quickly at higher temperature.
Diet: Because of starvation or serious abrupt calorie reduction, BMR can drop by about 30%. The low-calorie weight
loss diets can cause dropping of BMR to up to 20%.
External Temperature: External temperature also affects BMR. Exposure to cold temperature leads to increase in
BMR, in order to create an extra heat to body’s internal temperature.
Exercise: Physical exercise decreases body weight by burning calories as well as increases BMR by building extra
lean tissue. Some short term factors affecting BMR are high levels of stress hormones, certain illnesses such as fever
and increase or decrease in environmental temperature. These factors cause an increase in BMR. Starvation, fasting
or malnutrition results in lowering BMR.
How To Calculate BMR?
While designing a personal nutrition plan you need to calculate the calories that you burn in a day. Total daily energy
expenditure (TDEE) is a total number of calories that are spend by the body within 24 hours doing all activities. TDEE
is also known as the maintenance level. The calorie expenditure can vary from person to person and it is much higher
in extremely active people or the athletes.
English BMR Formula
Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )
Harris Benedict Formula
To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:

If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2

If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375

If you are moderately active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55

If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725

If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9
Total Calorie Needs Example
If you are sedentary, multiply your BMR by 1.2, this is the total number of calories you need in order to maintain your
current weight.
Once you know the number of calories needed to maintain your weight, you can easily calculate the number of
calories you need to eat in order to gain or lose weight:
Calorie Needs to gain weight
Once you know the number of calories you need to maintain your weight you can easily calculate the number of
calories you need in order to gain weight.
If you want to gain body weight, you need to consume more calories than you burn. One pound of body weight is
roughly equivalent to 3500 calories, so eating an extra 500 calories per day will cause you to gain one pound a week.
For optimum health, if you increase your calories to gain weight then (health permitting) gradually increase your level
of physical exercise in order to maintain or increase your lean body mass. The benefits of exercise on physical and
mental health are well documented and shouldn't be ignored.
Calorie Needs to lose weight
There are approximately 3500 calories in a pound of stored body fat. So, if you create a 3500-calorie deficit through
diet, exercise or a combination of both, you will lose one pound of body weight. The calorie deficit can be achieved
either by calorie-restriction alone, or by a combination of fewer calories in (diet) and more calories out (exercise). This
combination of diet and exercise is best for lasting weight loss. Indeed, sustained weight loss is difficult or impossible
without increased regular exercise.