What is TDEE?
Total Daily Energy Expenditure (TDEE) is an estimation of how many calories you burn per day when physical activity is taken into account. It is the most important metric to know when you are trying to lose weight, gain muscle, or simply maintain your current physique.
Your body burns calories constantly, not just when you are at the gym. TDEE encompasses everything: the calories required to keep your organs functioning (BMR), the calories burned breaking down food (TEF), the calories burned through fidgeting and walking (NEAT), and the calories burned during structured exercise (EAT).
How TDEE is Calculated
To find your TDEE, we first calculate your Basal Metabolic Rate (BMR) using the highly accurate Mifflin-St Jeor equation. We then multiply your BMR by an Activity Multiplier based on your lifestyle.
- Sedentary (x 1.2): Little to no exercise, desk job.
- Lightly Active (x 1.375): Light exercise or sports 1-3 days a week.
- Moderately Active (x 1.55): Moderate exercise or sports 4-5 days a week.
- Active (x 1.725): Hard exercise or sports 6-7 days a week.
- Very Active (x 1.9): Very hard daily exercise and a physical job.
Using TDEE for Weight Management
Once you know your TDEE, controlling your weight becomes a simple matter of energy balance thermodynamics:
- Maintenance: Eat exactly your TDEE amount to keep your weight the same.
- Cutting (Weight Loss): Eat 500 calories less than your TDEE. This creates a caloric deficit that typically results in 1 lb of fat loss per week.
- Bulking (Muscle Gain): Eat 300 to 500 calories more than your TDEE, combined with resistance training, to build muscle mass.
Frequently Asked Questions (FAQ)
1. Should I recalculate my TDEE as I lose weight?
Yes. Because your BMR is partially based on your total body weight, as you lose weight, your body requires fewer calories to sustain itself. It is best practice to recalculate your TDEE every time you lose or gain 5 to 10 pounds (2.5 to 4.5 kg) to avoid hitting a plateau.
2. Do I need to eat back the calories I burn from exercise?
No. Your Activity Level multiplier already accounts for your exercise. If you selected "Moderately Active," those gym sessions are already factored into your final TDEE number. Eating extra calories on top of that will put you in a surplus.
3. Is TDEE 100% accurate?
TDEE is a mathematical estimation based on population averages. While the Mifflin-St Jeor equation is incredibly accurate, individual metabolisms, genetics, and body compositions can cause slight variations. Think of your TDEE result as a starting baseline. Track your weight for two weeks while eating that amount; if your weight doesn't move as expected, adjust your calories by 100-200 up or down.