Energy Balance
- Intake ≈ Expenditure: Weight tends to stay stable.
- Intake > Expenditure: Potential weight gain.
- Intake < Expenditure: Potential weight loss.
Simplified model. Hormones, genetics, sleep, stress and metabolic adaptation also influence outcomes.
Estimated Daily Requirements
From Australian Nutrient Reference Values — population estimates.
| 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 |
| Men 51–70 | ~9,000 | ~10,500 | ~12,200 |
| Women 19–30 | ~7,900 | ~9,100 | ~10,800 |
| Women 31–50 | ~7,600 | ~8,800 | ~10,400 |
| Women 51–70 | ~7,200 | ~8,400 | ~9,800 |
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 | Description | Factor |
|---|---|---|
| Sedentary | Desk job | 1.2 |
| Lightly active | 1–3 d/wk | 1.375 |
| Moderately active | 3–5 d/wk | 1.55 |
| Very active | 6–7 d/wk | 1.725 |
| Extremely active | Physical job | 1.9 |
Example
32-year-old woman, 168 cm, 64 kg, moderately active:
- BMR = 640 + 1,050 − 160 − 161 = 1,369 kcal
- TDEE = 1,369 × 1.55 = ~2,122 kcal (≈ 8,878 kJ)
Approximate only. Consult an accredited dietitian for personalised guidance.
Practical Tips
- Prioritise whole foods.
- Portion awareness over rigid counting.
- Include all five food groups.
- Limit ultra-processed foods and added sugars.
- Eat mindfully.
Disclaimer: General education only. TrueForm does not guarantee weight-management outcomes.