How to Determine your Basal Metabolic Rate
If you’re trying to lose fat, knowing your basal metabolic rate is one of the most important things you should know. Your basal metabolic rate indicates how many calories your body will use just to maintain life. One of the best things you can do to lose fat is to increase your basal metabolic rate.
You can do many things, but losing weight requires a caloric deficit. One of the most effective ways to achieve that is to raise your basal metabolic rate, because any increase in the rate is multiplied throughout the 24 hour day.
The reason you should be able to calculate your basal metabolic rate is to know your basic caloric intake target. You have to know your target caloric intake to ensure you don’t make one of the common errors in weight loss; actually eating too few calories. Eventually that weight loss strategy will make you look like a shipwreck or concentration camp survivor. In so doing you’ll lose more than just fat. Just about all you muscle will go bye-bye too.
Restricting your caloric intake too much will cause your basal metabolic rate to drop by as much as 30%. That will obviously make it far tougher to lose fat. To prevent that, simply calculate your basal metabolic rate as a starting point or your caloric intake. You’ll probably have to adjust it some from there.
The following basal metabolic rate calculation is the Katch – McArdle formula, as opposed to the popular Harris-Benedict formula. I like the Katch-McArdle formula because it takes into account your lean body mass, instead of just weight and height. In theory the result should be more accurate this way. The higher percentage of lean body mass you have, the higher your basal metabolic rate should be. Obviously, because the formula considers lean body mass, you’ll have to determine your lean body mass before using it.
The Katch-McArdle Basal Metabolic Rate Calculation Formula
BMR (works for both men and women) = 370 + (21.6 X lean mass in kg)
As an example, if your weight is 215lbs and your body fat percentage is 20%, you have 43 pounds of body fat and 172lbs of lean body mass. A kilogram = 2.2 lbs, so 172/2.2 = 78.19 kilos. If you plug that into the formula you get the following:
370 + (21.6×78.19) = 370 + 1,689 = 2,059 calorie basal metabolic rate.
If you have this rate and currently do not exercise, you can eat a 3% – 5% percentage points less than this to lose fat. However, a far more effective fat loss strategy would be to start a modest exercise routine. You would increase your basal metabolic rate due to the increased activity level and the increased muscle mass you’d generate from the exercise. The exercise would also guard against your metabolic rate dropping due to the decreased caloric intake.