How Many Calories Do I Burn a Day?

Most individuals concerned with losing, gaining or maintaining weight wish to know how many calories they burn over the course of a day. The calorie out equation adds the basal metabolic rate, lifestyle activity level and calories burned during exercise. The sum determines how many calories an individual should eat in a given day.

Features

Total metabolism depends on the basal metabolic rate, lifestyle activity level and calories burned during exercise. The basal metabolic rate is the amount of calories needed to sustain basic body processes. If an individual stayed in bed for 24 hours, the amount of calories needed for this individual to maintain current weight is the basal metabolic rate. The amount of calories burned by lifestyle activity level depends on how active a person is during the day. A server at a restaurant working an eight-hour shift will burn more calories than an accountant sitting at a desk for eight hours. The amount of calories burned during exercise can be determined by wearing a heart rate monitor or typing information into a cardiovascular machine so it can guess how many calories were burned during a bout of exercise.

Function

The most accurate method of determining how many calories an individual burns during the day is the resting metabolic rate (RMR) test. The test is typically taken in a relaxed, fasted state. The individual wears a mask or mouthpiece connected to a computer. The machine determines how many calories are burned during the day by measuring the amount of oxygen taken in compared to the amount of carbon dioxide exhaled. The resting RMR test is available in many health clubs and hospitals. If the test is not available, a guess would average 10 calories per pound of bodyweight. For example, the resting metabolic rate of a 150-pound individual would be 1,500 calories.

Considerations

One pound equals 3,500 calories. In theory, an individual wishing to lose one pound per week would eat at a 500 calorie deficit over the course of 7 days, equaling 3,500 calories. When determining how many calories to eat, do not forget to add calories burned during exercise to the equation. From the example above, the 150 pound individual, burning 500 calories during exercise would eat 1,500 calories per day to lose one pound a week.

Expert Insight

Individual metabolism is determined by age, gender and body fat percentage. Metabolism decreases with age. Men have higher metabolisms than women. At any age, regardless of gender, muscle is more active than fat. Where one pound of fat may add two to three calories per day to metabolism, a pound of muscle will add 50 to 70 calories. Take two male individuals with the same age, height and weight, and the one with more muscle and less fat will have the higher metabolism.

Warning

Do not try to lose more than two pounds in one week. When an individual eats at a deficit of more than 1,000 calories per day, the body decreases metabolism. In this case the body does not know the difference between dieting and starving. When the body is starving, the body naturally cuts back all body processes to prepare for a long period of starvation. While the mind may know food is readily available, the body does not know when it is going to eat again.