Energy in. Energy out. Sounds simple, right? When you plan your meals and activity for the week, you want to make sure you eat enough to provide the energy you need for your workouts. And if you are trying to lose weight, you want to make sure you have a calorie deficit for the week. The question is, how do you know how many calories your body uses each day? There is no one answer to this question since everyone’s body burns a different amount of calories each day. This can depend on your age, gender, activity level, current height and weight, as well as how your body digests food, among other things. Therefore, you will need a way to calculate your calories burned each day taking all of these things into account. This may sound overwhelming, but you can estimate all of these things by using the calculation for total daily energy expenditure.
What is total daily energy expenditure?
To put it simply, total daily energy expenditure (TDEE) is the amount of energy used by humans or animals through movement and needed to keep the body working healthfully. TDEE is not just a single measure, but is calculated as a sum of the following three forms of energy:
- BMR, or basal metabolic rate. The BMR is basically the amount of energy your body uses to keep you breathing and your blood flowing. BMR is considered a function of lean mass and accounts for about 60-percent of the TDEE.
- The thermic effect of food (TEF) is the amount of energy used to digest, absorb, and store nutrients from what you eat and drink. This only accounts for about 10-15-percent of the TDEE.
- Physical activity level (PAL) – Physical activity level makes up about 15-30-percent of the TDEE, and accounts for two factors:
- EAT – Exercise-related Activity Thermogenesis, which refers to the energy burned through organized exercise,
- NEAT – Non-Exercise-related activity thermogenesis. NEAT accounts for every other physical movement. NEAT includes activities of daily living, fidgeting, maintaining posture, standing, sitting, and many other unplanned movements.
TDEE vs. BMR
While BMR is a single measure of the energy your body uses at rest, TDEE includes the BMR along with other ways your body uses energy each day. Which means that BMR is only one part of the puzzle when it comes to calculating the TDEE.
These other ways are known as Non-Resting Energy Expenditure (NREE).
-EAT Exercise-related Activity Thermogenesis
-NEAT Non-Exercise-related activity thermogenesis.
-TEF Thermic Effect of Food
TDEE = BMR + NREE
How to estimated TDEE?
BMR is usually multiplied by the physical activity factor to estimate TDEE. The physical activity factor provides a number to represent each level of physical activity.
- 1.2: sedentary behavior
- 1.375: 1-3 days of light exercise each week
- 1.55: moderate exercise such as brisk walking or swimming, for 3-5 days each week
- 1.725: vigorous exercise such as running for 6-7 days each week
- 1.9: hard daily exercise along with a physical job or training
Ways to measure TDEE
The current gold-standard method of measuring energy expenditure is the doubly labeled water (DLW) method since it is noninvasive. It involves drinking a formulated water and getting urine tests done thereafter. However, it can be expensive, and does not consider energy used through exercise.
Another way to measure TDEE is indirect calorimetry. This method involves the measurement of inhaled oxygen and exhaled carbon dioxide gases. However, this test is usually limited to research purposes.
Therefore, the best estimate of TDEE without requiring a lab or trained staff is to use a TDEE calculator. A TDEE calculator can estimate your TDEE as best as possible by using information like your height, weight, age, and activity level. Although this estimate is not the most accurate way to calculate TDEE, it is the most practical to keep track of your TDEE on a regular basis.
So, there you have it. Now that you know how to calculate your energy used each day, you can plan your meals and workouts to keep this number in line with your fitness goals. Whether you want to lose weight, maintain weight, or gain, your TDEE is a vital tool for success.