BMR- Basal Metabolic Rate. To understand BMR we need to understand the TDEE(Total Daily Energy Expenditure) of our body. We consume energy for the vital function of our body, Physical Activity, and thematic effect of food.
Basal Metabolic Rate or Body Metabolic Rate is that how much energy expand to maintain a vital function of your body an activity like blinking, heart pumping, blood circulating, etc.
That if you rest on the bed and do nothing, then the amount of energy need to maintain your body activity is BMR.
The exact calculation of the BMR of an individual is not possible. But we can calculate the approximate value of it. On that base, we can correct our intake and maintain our weight and health. There are various methods to estimate BMR. Some of the well known and used equations as follows:
HARRIS - BENEDICT EQUATION :This is the most widely used equation to calculate BMR published in 1919. The calculation methods for men and women are different, mainly due to differences in body mass or weight. The revised Harris-Benedict equation published in 1984. In our BMR calculation used revised Harris-Benedict equation.
For Men- BMR=13.397 X W + 4.799 X H(cm) - 5.677 X A + 88.362Calories/day
For Women- BMR=9.247 X W + 3.098 X H(cm) - 4.330 X A + 447.593Calories/day
*** W=body weight in kg, H=height in cm, A=age in years.
BMR=10 X W + 6.25 X H(cm) - 5.0 X A + sCalories/day
*** W=body weight in kg, H=height in cm, A=age in years. s=+5 for males and -161 for female
SCHOFIELD EQUATION :This method of estimating BMR was introduced for adult men and women in 1985. This equation was used by WHO to make a technical report. This method uses individuals' body mass and age range to estimate BMR. There are different charts for men and women.
|< 3||59.512 X W - 30.4||70|
|3 - 10||22.706 X W + 504.3||67|
|10 - 18||17.686 X W + 658.2||105|
|18 - 30||15.057 X W + 692.2||153|
|30 - 60||11.472 X W + 873.1||167|
|60||11.711 X W + 587.7||164|
|< 3||58.317 X W - 31.1||59|
|3 - 10||20.315 X W + 485.9||70|
|10 - 18||13.384 X W + 692.6||111|
|18 - 30||14.818 X W + 486.6||119|
|30 - 60||8.126 X W + 845.6||111|
|60||9.082 X W + 658.5||108|
*** W=body weight in kg, SEE- Standard Error of Estimation
This equation estimating BMR based on body mass and age range. SEE(Standard Error of Estimation), need to adjust upward or downward based on principles- more muscular people require more energy than the average one, Obese subjects require less.
RDEE=370 + (21.6 - L)Calories/day
L=W(1 - F/100)
*** W=body weight in kg, L=Lean body Mass in Kg., F=Body fat %