If you have ever thought about going on a diet, you probably know that to lose weight you have to burn more calories than you consume from your meals.
Calories are units of energy contained in the foods you eat. So you need to be able to answer the question, “How many calories do I need to consume every day, given my particular lifestyle and level of activity to BREAK EVEN?” (By break even I mean the number of calories you can consume daily, that will neither cause weight loss or weight gain).
In order to calculate this “break even” number of calories, you first have to determine your “BMR” (basal metabolic rate). In simple terms this is the number of calories you need to fuel basic body functions only. Imagine getting up and staying in bed and not walking or doing any other kind of work or exercise. The amount of calories required to do this is your BMR.
A simple formula allows both men and women to calculate their BMR.
Multiply your weight in pounds by 4.35 (write down that amount, and call it # 1).
Multiply your height in inches by 4.7 (write down that amount, and call it # 2).
Multiply your age in years by 4.7 (write down that amount, and call it # 3).
Add # 1 and # 2 together and to that amount add 655 (write that down and call it # 4).
Finally, subtract # 3 from # 4 (#4 minus #3) and THAT IS YOUR BMR in calories.
Multiply your weigh in pounds by 6.23 (write down that amount and call it # 1).
Multiply your height in inches by 12.7 (write down that amount and call it # 2).
Multiply your age in years by 6.8 (write down that amount and call it # 3).
Add # 1 and # 2 together and to that amount add 66 (write that down and call it # 4).
Subtract # 4 from # 3 (#3 minus #4) and that amount is your BMR in calories.
Remember your BMR is just the minimum amount of calories you need to keep your body functions running, it doesn’t’ reflect the additional calories you need to provide energy for walking around and doing physical tasks. So now that you know your BMR you can multiply it by the following factors that vary depending upon how active you are.
If you basically sit at a desk all day and don’t exercise on a consistent basis then multiply your BMR by 1.2
If you are slightly active (light exercise 1-3 days a week) multiply your BMR by 1.375
If you are moderately active (moderate sports 3-5 days a week) multiply your BMR by 1.55
If you are very active (hard exercise 5-7 days a week) multiply your BMR by 1.725
The result of multiplying your BMR times these factors gives you the amount of calories you can consume daily without losing or gaining weight. If you are extremely muscular, with little body fat, you can consume 15-20% MORE than you calculated to maintain your current weight. If you are over-weight by 30 lbs or more, you need to consume 15-20% LESS than you calculated to maintain your current weight.
Ok! Now you know how many calories you can consume daily to maintain your current weight, but many of you reading this article will want to be able to calculate how many LESS calories you will have to eat daily to lose weight. Since a pound of fat contains about 3500 calories, to lose a pound of fat a week you have to create a caloric deficit of 3500 calories. Dividing 3500 by 7 = 500 calories. So you have to take in 500 calories less than your calculated amount every day to lose one pound of fat each week. This may not sound like a lot but at the end of four months, you will have lost 16 lbs of fat.
There are many online calorie tracking systems, one is offered by Google: GOOGLE CALORIE COUNTER: Track calories and manage meals quickly and easily.
If in addition to the reduction in daily calorie intake, you also introduced a daily 30-minute walk, you would lose 24 lbs. of fat in four months. That’s pretty darn good! Excess weight places undue strain on your heart and joints and is known to increase the risk of cancer, arthritis, diabetes, and even dementia.
I hope that I didn’t overwhelm you with math but made it easier for you to determine specifically what you need to do to get slimmer and healthier.
Curt Hendrix, M.S, C.C.N, C.N.S.