Glossary

TDEE (Total Daily Energy Expenditure)

Metabolism Energy Expenditure Calories & Weight

Total daily energy output — composed of BMR, NEAT, TEF (thermic effect of food) and EAT (planned exercise). A key metric for muscle gain, maintenance and recovery in hardgainers.

Notice

This page provides context and guardrails. It is not individual medical, nutritional or training advice. Suitability and tolerance are individual; consult professionals if unsure.

Definition and System Context

Quick recap TDEE is the sum of all components of daily energy expenditure. It defines how many calories you burn per day — and frames your strategy for growth, maintenance or deficit.

  • BMR: Resting metabolism — see BMR.
  • NEAT: Non-exercise activity — see NEAT.
  • TEF: Digestive cost — see TEF.
  • EAT: Planned training (resistance/cardio) — see EAT.
Notice

TDEE is dynamic: more activity or muscle → higher output; dieting or inactivity → lower output.

Key Factors and Dynamics

  • Body weight & muscle mass: drive BMR.
  • Activity: NEAT and EAT are the most variable levers.
  • Diet & TEF: high-protein diets raise TEF; meal timing influences peaks.
  • Adaptations: During dieting, NEAT and hormonal drive often drop → lower TDEE.
Notice

Hardgainers often have high NEAT and faster metabolism — accurate TDEE calibration is vital to stay in a lean surplus.

Calculation & Application

Start with a formula — refine with real-world data:

  • Formula: BMR × activity factor (e.g. 1.6 for moderate activity).
  • Empirical: Track calories & body weight for 10–14 days → weekly average → back-calculate actual TDEE.
  • Proxies: Steps (NEAT), training volume (EAT), and meal rhythm (TEF) contextualize energy flux.
Hardgainer Calorie Calculator Maintenance Calories
Notice

Calculators provide starting points — true calibration emerges from trends in weight, steps & Rate of Gain.

Practical Guardrails

  • For growth: TDEE + 5–10% → Lean Surplus.
  • For maintenance: Intake ≈ TDEE → Maintenance.
  • For fat loss: TDEE − 10–20% → moderate deficit.
Notice

If progress stalls: reassess NEAT/EAT, TEF (meal rhythm) & total intake instead of cutting calories blindly.

Featured entry

Metabolism System – BMR, NEAT, EAT, TEF and TDEE at a glance

The Metabolism Flow shows how BMR, NEAT, EAT and TEF together build your daily energy expenditure (TDEE) – with typical percentage ranges, hardgainer context and clear orientation guardrails instead of rigid prescriptions.

Use it as your homebase when tuning maintenance calories, a lean surplus or your rate of gain in a structured way.

🔎 View Metabolism System

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Notice: Descriptive context — not a prescription. Individual differences and possible contraindications apply.

Notice

Descriptive information for orientation — not a treatment, diet or training prescription. Individual differences and possible contraindications apply.

© Hardgainer Performance Nutrition® • Glossary • Updated: Nov 21, 2025