A practical overview of how energy balance works, with reference tables for common Australian foods and general activity expenditure estimates.
Energy balance refers to the relationship between the energy (measured in kilocalories or kilojoules) you consume through food and drink, and the energy your body expends through basal metabolic functions, physical activity and the thermic effect of food. When energy intake approximately matches energy expenditure over time, body weight tends to remain stable. A sustained surplus may lead to weight gain, while a sustained deficit may lead to weight loss.
It is important to note that energy balance is a simplified model. Hormonal factors, sleep quality, stress, gut microbiome composition and individual metabolic variation all influence how the body processes and stores energy. Calorie counting can be a useful awareness tool but should not become an obsessive practice.
The following table provides general estimates based on Australian dietary guidelines. Actual requirements depend on age, sex, body composition, activity level and metabolic health.
| Group | Sedentary (kcal) | Moderately Active (kcal) | Active (kcal) |
|---|---|---|---|
| Women 19–30 | 1,800–2,000 | 2,000–2,200 | 2,200–2,400 |
| Women 31–50 | 1,800 | 2,000 | 2,200 |
| Men 19–30 | 2,400 | 2,600–2,800 | 3,000 |
| Men 31–50 | 2,200 | 2,400–2,600 | 2,800–3,000 |
| Adults 51+ | 1,600–2,000 | 1,800–2,200 | 2,000–2,600 |
The table below lists approximate calorie values for common food items available in Australia. Values are per standard serving size and sourced from Food Standards Australia New Zealand (FSANZ) nutrient databases where applicable.
| Food Item | Serving Size | Approx. kcal | Protein (g) |
|---|---|---|---|
| Rolled oats (dry) | 40 g | 152 | 5.3 |
| Chicken breast (grilled) | 120 g | 198 | 37 |
| Brown rice (cooked) | 150 g | 170 | 3.8 |
| Avocado | ½ medium (75 g) | 120 | 1.5 |
| Banana | 1 medium (120 g) | 105 | 1.3 |
| Greek yoghurt (plain) | 170 g | 150 | 15 |
| Whole egg | 1 large (50 g) | 72 | 6.3 |
| Sweet potato (baked) | 150 g | 135 | 2 |
| Atlantic salmon fillet | 125 g | 260 | 28 |
| Broccoli (steamed) | 100 g | 35 | 2.8 |
| Almonds | 30 g (small handful) | 175 | 6.3 |
| Wholemeal bread | 1 slice (36 g) | 82 | 4 |
The following estimates are for a 70 kg individual. Values will be higher for heavier individuals and lower for lighter individuals, roughly proportional to body weight.
| Activity | Duration | Approx. kcal Burned |
|---|---|---|
| Walking (5 km/h) | 30 min | 130 |
| Jogging (8 km/h) | 30 min | 280 |
| Cycling (moderate) | 30 min | 250 |
| Swimming (freestyle, moderate) | 30 min | 250 |
| Resistance training (moderate) | 45 min | 220 |
| Yoga (hatha) | 60 min | 180 |
| Sitting (desk work) | 60 min | 70 |
Rather than aiming for precise calorie counts, consider these general principles for managing energy balance: