1. BMR — Mifflin-St Jeor (default)
Male: 10 × kg + 6.25 × cm − 5 × age + 5 Female: 10 × kg + 6.25 × cm − 5 × age − 161
This is the most accurate formula for the general population (±10% for most).
2. BMR — Katch-McArdle (with body fat %)
BMR = 370 + 21.6 × lean body mass (kg) lean mass = weight × (1 − body fat % / 100)
More accurate for athletic or very lean/obese individuals when body-fat % is known.
3. Activity multipliers (TDEE)
| Level | Multiplier |
|---|---|
| Sedentary (desk job) | × 1.2 |
| Light (1–3 days/week) | × 1.375 |
| Moderate (3–5 days) | × 1.55 |
| Active (6–7 days) | × 1.725 |
| Very active (2x/day, manual labor) | × 1.9 |
4. Goal-based target kcal
- Lose: TDEE − 500 kcal (≈ 0.45 kg/week)
- Maintain: TDEE
- Gain: TDEE + 300 kcal (≈ 0.25 kg/week)
- Cut: TDEE × 0.8, with minimum 1,200 kcal
5. Macro recommendations
- Protein: 1.6 g/kg for most (2.2 g/kg during cut, 1.8 g/kg during gain).
- Fat: 25% of calories (28% during gain for hormonal support).
- Carbs: remainder.
6. When to deviate
- Endurance athletes benefit from higher carbs (50–60% of kcal).
- Keto diets push fat to 70% and carbs to 5–10%.
- Older adults may need protein as high as 2.0 g/kg to preserve muscle.
7. References
- Mifflin et al., Am J Clin Nutr 1990.
- Katch-McArdle, Exercise Physiology.
- ISSN Position Stand: Protein & Exercise.