Calorie Requirements

• Your daily calorie needs are dependent on several factors, including your age, height, gender, genetic metabolism and the amount of exercise you get on a daily basis. Your calorie count can fluctuate from day to day based on changes in these factors. Men need more calories per day than women, and active individuals need more calories than people who get very little exercise.
  
  A single pound of stored body fat contains approximately 3,500 calories. To lose one pound of fat a week, you would need to take in 500 fewer calories a day. To gain a pound a week you would need to increase your calorie count by 500 calories.
  
  

BMR

• The first step in determining how many calories you need each day is to calculate your BMR, or basal metabolic rate. The BMR measures the minimum number of calories you need each day to keep your body alive while in a resting state. BMR accounts for approximately 70 percent of our daily calorie expenditure. BMR measures the calories burned by activities such as breathing and blood circulation.
  
  Use the Harris-Benedict formula to manually calculate your BMR. For men, the formula is: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years). For women the formula is: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years). The Harris-Benedict formula may not accurately measure your calorie needs if you are extremely overweight or if you are very muscular.
  
  A much easier way to calculate your BMR is to use an online BMR calculator, such as the one at www.bmi-calculator.net. You can type in the keywords "BMR calculator" in a search engine.
  
  

Activity Level

• The Harris-Benedict formula indicates how many calories you need to maintain your current weight based on your lifestyle. If you get very little or no exercise, multiply your BMR by 1.2. If you get some exercise, multiply your BMR by 1.375. If you exercise 3 to 5 days a week, multiply your BMR by 1.55. If you engage in hard exercise 6 to 7 days a week, multiply your BMR by 1.725. If you are extremely active and exercise hard on a daily basis, multiply your BMR by 1.9.