How to calculate your Basal Metabolic Rate (BMR)

The BMR is an acronym for Basal Metabolic Rate. This is the amount of energy your body uses daily when at rest. It is the amount of calories your body burns on its own daily whether you exercise or not. Each individuals metabolic rate is different. How do you determine your own BMR?

First, you need to understand what a calorie is. Just like a quart is a measurement of volume, and an inch is a measurement of length, a calorie is a measurement or unit of energy. The number of calories in the foods you eat is a measurement of the number of energy units that food supplies. Those energy units are used by the body to fuel physical activity as well as metabolic processes, from maintaining your heartbeat, to growing your hair and building muscle. Only four (4) components of food supply calories. Proteins and carbohydrates supply four (4) calories per gram, fat supplies nine (9) calories per gram while alcohol supplies seven (7) calories per gram.

Calories from fat are more fattening than calories from protein and carbohydrate. This is because fat is more readily stored in the body as fat but the body has to work harder to convert carbohydrates and proteins to body fat. That increased work leads to a slight loss. For instance, when 20g of  butter enters into your body, your body would use only 3 percent of its calories to convert it into body fat but your body would need to use about 23 percent of the calories in carbohydrates and proteins to convert them into fat for storage in the body.

To calculate your unique metabolic rate, you'll need a pen, paper and calculate.

The formula to determine your BMR:
Women: 655 + (4.35 x your weight in pounds) + (4.7 x your height in inches) - (4.7 x your age).
Men : 066 + (6.23 x your weight in pounds) + (12.7 x your height in inches) - (6.8 x your age).

So if Nancy is 25 years old, weighs 200 pounds and is 5.5 inches tall, her BMR will be:
655 + (4.35 x 200) + (4.7 x 5.5) - (4.7 x 25)
655 + 870 + 26 - 118 = 1,433

Now that you know your BMR, the next thing is to factor in your daily activity level. Choose one of the following as it applies to you :
Sedentary ( You do not exercise at all) : BMR x 1.2
Lightly active ( You  get light exercises 1 to 3 days a week) : BMR x 1.375
Moderately Active ( Moderate exercises 3 to 5 days a week) : BMR x 1.55

Now, we already know that Nancy's BMR is 1,433. So, if Nancy gets no exercise at all, she lives a sedentary lifestyle therefore:
1,433 x 1.2 = 1,720.

So Nancy's body burns 1,720 calories day. Which means Nancy's body needs 1,720 calories to function each day. How many calories does your own body need daily?

Now that you know what your body needs to function daily, and you also know that to lose 1 pound/0.45 kg, you'll need to burn 3,500 calories, how do you achieve weight loss?

You simply create a deficit!

If you want to lose 1 pound per week, it means you need to find a way to burn 500 calories each day. For instance, if your BMR IS 1,702, you'll supply your body with 1,202 calories  and force it to go to the 'fat store' for more. You can force your body to go to the fat store(burn stored fat) by creating a deficit of 500 calories daily. If your body needs 1,702 calories to function, you can burn 250 calories through exercises which leaves your body with just 1,452 calories right? Then reduce your food intake by another 250 calories.

This means that you should feed your body with just 1,200 calories daily so that it goes to the fat store to get the extra 500 calories it needs. That way, you'll burn 500 calories a day and lose 0.45 Kg each week. If you need to lose more per week, you can tweak it to suit your need. For instance, if you need to lose 2 pounds per week, that's 7,000 calories to burn weekly and 1,000 calories daily. But you should note that losing more than 2 pounds per week is a bad idea and may be counterproductive.