Energy Balance
- Intake ≈ Expenditure: Weight stable.
- Intake > Expenditure: Potential gain.
- Intake < Expenditure: Potential loss.
Simplified. Hormones, genetics, sleep, stress also influence outcomes.
Estimated Daily Requirements
| Group | Sedentary (kJ) | Moderate (kJ) | Active (kJ) |
|---|---|---|---|
| Men 19–30 | ~10,000 | ~11,500 | ~13,500 |
| Men 31–50 | ~9,700 | ~11,200 | ~13,000 |
| Women 19–30 | ~7,900 | ~9,100 | ~10,800 |
| Women 31–50 | ~7,600 | ~8,800 | ~10,400 |
Conversion: 1 kcal = 4.184 kJ. 8,700 kJ ≈ 2,080 kcal.
Macronutrients
| Macro | AMDR (%) | kJ/g | Functions |
|---|---|---|---|
| Carbs | 45–65 | 17 (4 kcal) | Primary energy; brain fuel; fibre |
| Protein | 15–25 | 17 (4 kcal) | Tissue repair; enzymes; immune |
| Fat | 20–35 | 37 (9 kcal) | Hormones; energy store; vitamins |
BMR Estimation (Mifflin-St Jeor)
- Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
- Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161
Activity Multipliers
| Level | Factor |
|---|---|
| Sedentary | 1.2 |
| Lightly active | 1.375 |
| Moderately active | 1.55 |
| Very active | 1.725 |
| Extremely active | 1.9 |
Example
34-year-old woman, 166 cm, 63 kg, moderately active:
- BMR = 630 + 1,037.5 − 170 − 161 = 1,336.5 kcal
- TDEE = 1,336.5 × 1.55 = ~2,072 kcal (≈ 8,669 kJ)
Approximate only. Consult an accredited dietitian for personalised guidance.
Disclaimer: General education. VitalBasis does not guarantee weight-management outcomes.