The Calorie is a unit of energy used to describe energy content of foods. There are two types of calorie. One is small calorie and the other one is big calorie or kilocalorie. One kilocalorie equals to 1000 small calories. Big calorie or kilocalorie can also be referred to as Calorie. Biological molecules of food that we eat contain Calories. Burning of biological molecules through cellular respiration, releases the energy that we need for metabolism and other activities. If we consume more Calories than we consume then the extra Calories get stored as fat. As a result, we gain weight. On the other hand, if we consume less number of Calories than we do burn, we lose weight. Maintaining or losing weight is about having a balance between Calorie intake and Calorie expenditure.
Calorie intake can be calculated by adding up Calories of food that we eat. Calculating Calorie expenditure is about calculating and adding up Resting Metabolic Rate (RMR) and extra energies consumed because of exercises or thermal effect of exercise (TTE).
Resting Metabolic Rate is the energy that body expends during rest. The body expends this energy to stay alive by running functions such as lungs breathing, heart beating etc. Resting Metabolic Rate depends on variables such as body weight, sex and age. Genetic factors also affect Resting Metabolic Rate. To simplify calculation, genetic factors are not taken into consideration in calculation.
There is equation for calculating Resting Metabolic Rate. Weight has to be input in kilograms in the equation. By dividing pounds by 2.2, we can get weight in kilograms. Following are the equations for calculating Resting Metabolic Rate for male of different age groups.
Calculating RMR (Calories per day) for Males
- For age group (0-3), the equation is (60.9 * weight) – 54
- For age group (3-10), the equation is (22.7 * weight) + 495
- For age group (10-18), the equation is (17.5 * weight) + 651
- For age group (18-30), the equation is (15.3 * weight) +679
- For age group (30-60), the equation is (11.6 *weight) + 879
- For those who are above 60, the equation is (13.5 * weight) + 487.
Calculating RMR (Calories per day) for Females
- For age group (0-3), the equation is (61.0 * weight) – 51
- For age group (3-10), the equation is (22.5 * weight) + 499
- For age group (10-18), the equation is (12.2 * weight) + 746
- For age group (18-30), the equation is (14.7 * weight) + 496
- For age group (30-60), the equation is (8.7 * weight) + 829
- For those who are above 60, the equation is (10.5 * weight) + 596
Calculating Thermic Effects of Exercise
Thermic effects of exercise (TTE) is about the energy burnt because of exercises or activities in addition to functions responsible for RMR. Thermic effects of exercise has to be added with Resting Metabolic Rate, in order to calculate total Calorie expenditure.
Thermic effects of exercise depends on how active an individual is. Five levels of activity are used in calculation of TTE. These five levels include extremely active, very active, moderately active, lightly active and sedentary. Below are the definitions of these levels.
This level is about very low level of activeness such as watching TV, playing cards etc.
This level of activeness is of those who are homemakers, unemployed persons, lab workers, drivers, teachers, shop workers, doctors, lawyers, office workers, students etc. This level of activeness involves 16 hours of standing or sitting and 8 hours of sleep. Three out of sixteen hours must include light activities such as golf, ping-pong, laundry and walking. One out of sixteen hours has to include moderate activities such as dancing, tennis, aerobics etc.
This level of activeness is of those who are in electrical job, carpentry, light industry and building trades. This level does not involve heavy labor. Activeness of commercial fishermen, soldiers not in active service, many farm workers etc. belong to this level. Those who are in office job or driving and do 1.5 -2 hours of exercise per day, fall into this level in their activeness.
This level of activeness are of those who are steel workers, mine workers, soldiers in active service, forestry workers, many agricultural workers, unskilled laborers, athletes etc. Running 9 – 13 miles, a day is comparable to activeness of this level.
This level of activeness is of those who are involved in rickshaw pulling, coal mining, construction work etc. Running 14 – 17 miles, a day is comparable to activeness of this level.
Activity factor are also used in calculating TTE. Activity factors for different activity levels are as follows. At sedentary level, activity factor for men is 0.3 and activity factor for women is 0.3. At lightly active level, activity factor for men is 0.6 and activity factor for women is 0.5. At moderately active level, activity factor for men is 0.7 and activity factor for men is 0.6. At very active level, activity factor for men is 1.1 and activity factor for women is 0.9. At extremely active level, activity factor for men is 1.4 and activity factor for women is 1.2. In order to get TTE, RMR has to be multiplied by activity factor. Activity factor depends on the activity level of the person involved.
TTE = RMR * activity factor.
Total Calorie expenditure = RMR + TTE + 10% to TEF or 10% of (RMR +TTE). TEF is thermic effects of food.
The first step of calculating total calorie expenditure involves calculating RMR. The second step involves calculating TTE. The third step involves calculating TEF. The final step is to sum up RMR, TTE and TEF, which equals to total energy expenditure.
Last update: June 18, 2017 01:46:15 pm