Basal Metabolic Rate and Calculating Daily Caloric Needs

Basal Metabolic Rate what is it?

All the time we are above we are using energy. Energy to keep or vital organs functioning, energy to keep us warm, energy for digestion, producing enzymes, allowing muscles in our gut to move, our heart to beat. So even when we are at rest or even asleep, you can see we use energy.

The Basal Metabolic Rate is the amount of energy required for us to stay alive if totally sedentary, for example- staying in bed all day.

To calculate your BMR use your current weight and height measurements. There are two formulas, one for men and one for women. MAKE SURE YOU USE THE RIGHT ONE!


Imperial 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 )

Metric BMR Formula
Women: BMR = 655 + ( 9.6 x weight in kilos ) + ( 1.8 x height in cm ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 13.7 x weight in kilos ) + ( 5 x height in cm ) - ( 6.8 x age in years )

Once you have calculated your BMR you can then calculate your Daily Caloric Needs dependent upon your activity levels.

Your Daily Caloric Need number is the amount of energy required for you to sustain your weight at a specified activity level based around your BMR. To calculate it, see the table below:


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 moderatetely 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

The activity level also includes your general daily activity. So for example, If you are sedentary you probably work in an office at a desk in front of a computer with little exercise.

Lightly active would be the above doing exercise too around 3 times a week.
Moderately active would be someone who spends most of their day on their feet such as a nurse and who is doing exercise about 3 days a week.

This information can be used to determine if you are over or under eating for your activity, height and weight which can be useful if you are trying to lose or gain weight.

Next blog - keeping a food diary and then some recipes!!!