TDEE Explained: What Is Total Daily Energy Expenditure?

The Four Components of TDEE

BMR (Basal Metabolic Rate) — 60–70% of TDEE. Calories burned at complete rest. Driven primarily by lean muscle mass — which is why building muscle permanently increases your metabolism.

TEF (Thermic Effect of Food) — ~10% of TDEE. Calories burned digesting food. Protein has the highest thermic effect (20–30% of its calories), which is one reason high-protein diets aid fat loss.

EAT (Exercise Activity Thermogenesis) — 5–30%. Calories from intentional exercise — gym sessions, runs, sport.

NEAT (Non-Exercise Activity Thermogenesis) — 15–50%. The most underrated component. All movement that is not structured exercise: walking to your car, fidgeting, standing, cleaning. Research by Levine et al. found NEAT can vary by up to 2,000 calories per day between people of similar size.

Why NEAT Is a Game Changer

Two people of the same size can have TDEEs that differ by 600–800 calories per day purely because of NEAT differences. The sedentary person who sits still all day burns dramatically less than the fidgety, always-moving person. This explains why some people seem to “eat anything and not gain weight.” Increasing your daily step count to 8,000–12,000 is one of the most effective strategies for boosting TDEE without formal exercise.

How to Use Your TDEE

Fat loss: Subtract 500 calories from your TDEE. This produces approximately 0.5kg of fat loss per week — the sustainable rate that minimises muscle loss.

Muscle gain: Add 200–300 calories to your TDEE. A lean bulk at a small surplus maximises muscle gain while limiting fat.

Maintenance: Eat at your TDEE. Track for 2–3 weeks and adjust based on what the scale does.