Metabolism refers to the processes that the body needs to function. Basal Metabolic Rate is the amount of energy expressed in calories that a person needs to keep the body functioning at rest. Some of those processes are breathing, blood circulation, controlling body temperature, cell growth, brain and nerve function, and contraction of muscles.
Basal metabolic rate (BMR) affects the rate that a person burns calories and ultimately whether you maintain, gain, or lose weight. Your basal metabolic rate accounts for about 60 to 75% of the calories you burn every day. It is influenced by several factors.
Let’s find out how many calories you need to be taking in to lose weight.
Step 1) Find Your Basal Metabolic Rate (BMR)
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 years)
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)
A 40 year old male that weighs 200 pounds and is 5 foot 8 inches tall.
To determine height in inches, take the height in feet time 12, and then add the inches for your total height in inches.
5 x 12 = 60. Then 60 + 8 = 68 total inches tall.
Men: BMR = 66 + (6.23 x 200 pounds) + (12.7 x 68 inches) – (6.8 x 40 years old)
BMR = 66 + (1246) + (863.6) – (272)
BMR = 1903.6.
You can also use an on-line BMR Calculator Here
Step 2) Determine Your Daily Calories.
The Harris Benedict Equation is a formula that uses your BMR and then applies an activity factor to determine your total daily energy expenditure (calories). The only factor omitted by the Harris Benedict Equation is lean body mass. Remember, leaner bodies need more calories than less leaner ones. Therefore, this equation will be very accurate in all but the very muscular (will under-estimate calorie needs) and the very fat (will over-estimate calorie needs).
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 you’re BMR (1903.6) by 1.2 = 2284. This is the total number of calories you need in order to maintain your current weight.
For weight loss, our goal will be 500 calories below this number.
2284 – 500 = 1784
So for the example above, this person should be eating 1784 calories a day.
Find your BMR and write it down here__________.
Now use Harris Benedict Equation to find out how many calories you need to maintain your weight and write it down here_________.
Now subtract 500 from the above number and write it down here________. This is your daily calorie limit.