Your basal metabolic rate, or BMR, is the amount of calories needed to fulfill basic processes within your body. Your heart beats and your lungs continuously contract and expand 24 hours a day, seven days a week. These types of processes burn calories. Physical activity such as walking and any other type of movement will burn calories. To maintain your weight, the amount of calories you intake should equal the amount of calories expended (See References 1). The Harris-Benedict method was designed to determine the calories needed to carry out basic functioning based on your weight, height and age. Total caloric needs are determined when your level of physical activity is taken into account (See References 2).
Step 1
Make the necessary conversions for the Harris-Benedict equation to work correctly. Convert your weight from pounds to kilograms by multiplying your weight in pounds by 0.454. A weight of 118 lbs. converts to 53.57 kg. Convert your height from inches to centimeters by multiplying your height in inches by 2.54. A person with a height of 60 inches is 152.40 centimeters tall.
Step 2
Implement the Harris-Benedict Equation. If you are male, use the formula 66 + (13.7 x weight in kg) + (5 x height in centimeters) - (6.8 x age in years). Females should use the formula 655 + (9.6 x weight in kg) + (1.8 x height in centimeters) - (4.7 x age in years). This would yield 655 + (9.6 x 53.57) + (1.8 x 152.40) - (4.7 x 34) or 1283.80 for a 34-year-old woman with a weight of 53.57 kg and height of 152.40 centimeters.
Step 3
Multiply the product calculated in Step 2 by your activity level factor. The activity level factor for very light activity such as driving or typing is 1.3 for men and women. For light activities like housecleaning, it's 1.6 for men and 1.5 for women. Moderate activity like skiing or tennis has an activity factor of 1.7 for men and 1.6 for women. Heavy activity has a factor of 2.1 for men and 1.9 for women, and exceptional activity such as an athlete training for an event has a factor of 2.4 for men and 2.2 for women. Your result will be the number of calories needed daily to maintain your current weight. The woman in Step 2 engages in very light activity, and her daily caloric need is 1,668 calories.
References
- MayoClinic.com: Counting calories: Get back to weight-loss basics
- "Understanding Nutrition"; Eleanor Noss Whitney, Ph.D., R.D., Sharon Rady Rolfes, M.S., R.D.; 1993
Member Comments