1. The Reality Check

Every weight loss or muscle-gain plan ultimately comes down to one number: how many calories your body burns in a day. Get this number wrong, and even the most disciplined diet or workout plan will fail to produce the expected results.

2. Plain English Definition

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns per day, including your resting metabolism plus all activity — walking, exercising, even digesting food.

3. Why "Eyeballing It" Fails

Most people significantly overestimate how many calories they burn through exercise and underestimate how many they consume — a well-documented psychological bias. A proper TDEE calculation using established formulas removes the guesswork.

4. Key Terms

• BMR (Basal Metabolic Rate): Calories burned at complete rest, just keeping your organs running.
• Activity Multiplier: A factor applied to BMR based on how active your lifestyle is, producing TDEE.
• Caloric Deficit/Surplus: Eating below or above your TDEE to lose or gain weight respectively.

5. Next Steps

Calculate your TDEE above, then subtract 500 calories/day for a sustainable ~0.5kg/week weight loss rate.