Weight control is an issue for most adults, according to the Centers for Disease Control and Prevention. Whether you need to gain weight, lose weight or maintain a healthy weight, eating the right number of calories is key. Too many calories will result in weight gain for everyone, but too few may slow your metabolism. Learn how to calculate the right number of calories for your body, taking your size, age and activity level into consideration.
A calorie is a unit of energy derived from food. Your body does not distinguish between types of calories, whether they come from fat, protein or carbohydrates. Each pound of weight is equal to 3,500 calories; consuming 3,500 excess calories will result in a gain of 1 lb., while a 3,500-calorie deficit will result in a loss of 1 lb.
Your body uses the energy from food or calories while sleeping, resting, going about daily life and exercising. According to the American Heart Association, the number of calories you should have a day depends upon your age, size and daily activity level. If you are more active, you will have a higher metabolism and burn more calories daily.
Basal Metabolic Rate
The basal metabolic rate or BMR is the total number of calories your body would burn if you stayed in bed all day at rest. While the equation to determine this total is complex, easy to use online calculators can provide you with your basal metabolic rate, such as the one at the Fitness website. Input your current weight and age into the calculator; use this as a base for your total daily caloric intake.
Activity and Exercise
Your overall fitness level and daily activities will impact your BMR. The Harris Benedict equation is used to adjust your calorie guidelines, depending upon your lifestyle. Multiply your BMR by 1.2 if you are sedentary; multiply it by 1.375 if you engage in light exercise a few times a week. The BMR should be multiplied by 1.55, if you are quite active and 1.725 if you engage in hard exercise most days. This will provide you with an appropriate daily caloric guideline, but it does not actually account for calories burned during exercise if you are trying to maintain your weight.
Use a BMR calculator and the Harris Benedict equation to determine how many calories you burn in a day. If you want to lose weight, cutting 500 calories per day from this total will produce a weight loss of 1 lb. per week. If you exercise regularly, you can expect to see a 1 lb. to 2 lb. weight loss each week. Depending upon your size and age, expect to eat 1,200 to 1,800 calories a day when dieting.