Dieting can be like walking a tightrope between healthy and unhealthy weight loss. If you consume too many calories, you will lose weight slowly or not at all. On the other hand, if you consume too few calories, you will deprive your body of the energy and nutrition it needs to function. One way to make sure that you are not cutting too many calories is to determine your basal energy expenditure. This is the amount of energy your body requires to perform its normal functions. When multiplied by your daily activity factor, which describes the additional energy you need to maintain your lifestyle, this will give you an idea of how many calories your body needs per day and how many you can safely cut.
Women
Step 1
Substitute your weight in kilograms, your height in centimeters and your age into the Harris-Benedict Equation for women, which describes your basal energy expenditure: BEE = 655.1 + (9.563 x kg) + (1.850 x cm) - (4.676 x age).
For example, if a 35-year-old woman weighs 60 kg and is 160 cm tall, the equation would look like this: BEE = 655.1 + (9.563 x 60) + (1.850 x 160) - (4.676 x 35).
Step 2
Simplify the equation to calculate your BEE.
For instance, the BEE of the 35-year old woman would be 1,361.22 calories.
Step 3
Multiply your BEE by the activity factor that best describes your lifestyle. The result is the number of calories the average woman needs to consume in order to maintain her weight.
For example, if the 35-year-old woman walks a mile once or twice a week, she would be lightly active and have an activity factor of 1.375. Therefore, her daily calories needs would be 1,361.22 x 1.375 or approximately 1,872 calories.
Step 4
Subtract 500 to 1,000 calories from your daily calorie needs or reduce it by 15 to 20 percent. However, in no event should you reduce your calorie consumption below 1,200 per day unless you are under the supervision of a health care professional.
For instance, the woman could safely reduce her calories by 500 per day and consume a total of 1,372 calories, but she should not reduce it by 1,000 calories, which would cause her to consume only 872 calories per day.
Men
Step 1
Substitute your weight in kilograms, your height in centimeters and your age into the Harris-Benedict Equation for men: BEE = 66.5 + (13.75 x kg) + (5.003 x cm) - (6.775 x age). This equation describes your basal energy expenditure, or the number of calories your body requires to maintain its normal functions.
For example, if a 35-year-old man weighs 70 kg and is 175 cm tall, the equation would look like this: BEE = 66.5 + (13.75 x 70) + (5.003 x 175) - (6.775 x 35).
Step 2
Simplify the equation to determine your BEE.
For instance, the 35-year-old man's BEE would be 1,667.4 calories.
Step 3
Multiply your BEE by the activity factor that best describes your lifestyle. The result is the number of calories the average man needs to consume in order to maintain his weight.
For example, if the 35-year-old man worked out at the gym every other night after work, he would be moderately active and have an activity factor of 1.55. Therefore his daily calorie needs would be 1,667.4 x 1.55, or approximately 2,584 calories.
Step 4
Subtract 500 to 1,000 calories from your daily calorie needs, or reduce it by 15 to 20 percent. However, in no event should you reduce your daily calories below 1,800 per day unless you are under the supervision of a health care professional.
For example, the man could safely reduce his calorie intake by 700 calories, but not by 800, which would make his daily intake under 1,800 calories.
Tips and Warnings
- Examples of Activity Factors: Sedentary (little to no daily exercise): AF = 1.2 Lightly Active (light exercise 1 to 3 days per week ): AF = 1.375 Moderately Active ( moderate exercise 3 to 5 days per week): AF = 1.55 Very Active (hard exercise 6 to 7 days per week ): AF = 1.725 Extremely Active (hard daily exercise or physical job): AF = 1.9
- These formulas only provide an estimate of your caloric needs. Discuss your personal needs with your physician.
References
- Weill Medical College of Cornell University: Basal Energy Expenditure: Harris-Benedict Equation
- Kansas State University: Physical Activity and Controlling Weight
- Asian Hospital and Medical Center: Counting Calories For Weight Loss
- American College of Sports Medicine; Metabolism is Modifiable with the Right Lifestyle Changes; March 2009
Member Comments