TDEE defined
TDEE stands for Total Daily Energy Expenditure. It is the total number of calories your body burns in a single day, accounting for everything — your resting metabolism, the energy used digesting food, and all physical activity from workouts to walking to fidgeting.
TDEE is your maintenance level. If you eat exactly your TDEE every day, your weight stays constant. Eat less and you lose weight. Eat more and you gain weight. Understanding your TDEE is the most direct way to take control of your body composition.
TDEE vs BMR: what is the difference?
BMR (Basal Metabolic Rate) is the calories you burn at complete rest — the energy your body needs to keep organs functioning while you lie still and do nothing. It accounts for 60–70% of your total calorie burn.
TDEE is BMR multiplied by an activity factor. A sedentary 30-year-old woman with a BMR of 1,400 calories might have a TDEE of 1,680 (1,400 × 1.2 sedentary multiplier). The same woman exercising five days a week has a TDEE of approximately 2,170 (1,400 × 1.55).
The four components of TDEE
1. BMR (60–70% of TDEE): Your resting metabolic rate. Primarily determined by body size, muscle mass, age, and genetics. Muscle tissue burns approximately 3× more calories at rest than fat tissue.
2. TEF — Thermic Effect of Food (8–15% of TDEE): The calories burned digesting and processing food. Protein has the highest thermic effect (20–35% of its calories are burned in digestion), followed by carbohydrates (5–10%) and fat (0–5%). This is one reason high-protein diets support fat loss.
3. EAT — Exercise Activity Thermogenesis (15–30% of TDEE): Intentional exercise. Running, gym sessions, cycling, sports. This is the component most directly under your control.
4. NEAT — Non-Exercise Activity Thermogenesis (variable): All movement that is not intentional exercise — walking to your car, typing, fidgeting, household chores, standing vs sitting. NEAT varies enormously between individuals — up to 2,000 calories/day difference between very active and sedentary people at the same body weight. This is why some people seem to eat more without gaining weight.
How to calculate your TDEE
Use the Mifflin-St Jeor BMR formula, then multiply by the activity factor:
- Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
- Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
Activity multipliers:
- Sedentary (desk job, little movement): × 1.2
- Lightly active (light exercise 1–3 days/week): × 1.375
- Moderately active (exercise 3–5 days/week): × 1.55
- Very active (hard exercise 6–7 days/week): × 1.725
- Extra active (physical job or 2× daily training): × 1.9
Using TDEE to set your calorie target
Fat loss: Eat TDEE minus 250–500 calories for 0.5–1 lb per week loss. Do not go below 1,200 calories (women) or 1,500 calories (men).
Lean bulk (muscle gain with minimal fat): Eat TDEE plus 200–300 calories. This smaller surplus minimises fat gain while providing energy for muscle synthesis.
Maintenance: Eat at TDEE. Track weight for 2–3 weeks — if it is stable, your TDEE estimate is accurate. Adjust by 100 calories if weight is trending in the wrong direction.
Why your TDEE changes over time
Your TDEE is not static. As you lose weight, your BMR decreases because you have less body mass to maintain. A person who loses 30 lbs will burn approximately 150–200 fewer calories per day at the new weight, requiring a recalculation of their calorie target. Recalculate your TDEE every 10–15 lbs of weight change to avoid a plateau.
Metabolic adaptation also occurs during prolonged deficits — the body reduces NEAT (unconscious movement) and slightly lowers BMR as a survival response to restricted calories. This is the biological mechanism behind weight loss plateaus. A diet break at maintenance calories for 1–2 weeks can partially reset this adaptation.
Common TDEE mistakes
Overestimating activity level. Most people who go to the gym 3 times per week are "lightly active" during the rest of their time, not "moderately active." Choose the activity level that reflects your whole day, not just your workouts. Choosing too high an activity multiplier is the most common reason people eat at "maintenance" and still gain weight.
Not accounting for food tracking errors. Studies show people underestimate calorie intake by 20–40% on average. Weighing food instead of estimating portions can reveal significant discrepancies — a tablespoon of peanut butter measured vs estimated might be 100–200 calories apart.