If you have recorded all of your food consumed into a written record, the most accurate way of determining Kilojoules is using website or apps. For example:
- Calorie King: http://www.calorieking.com.au/
The websites allow you to; search for the specific food or drink consumed, enter in the weight or volume and then they provide you with the kilojoules and macronutrients. You can then record this into your paper based food record.
If you use an app, you still search for the food/drink consumed and enter volume but the app keeps track of kilojoules and nutrients (so you won’t need to go and record in the paper record).
Tip: Some websites or apps may use calories (kcal) instead of kilojoules (kJ). To convert 1kcal Is 4.2kJ. Therefore multiply the kcal by 4.2 to get from kcal to kJ or divide by 4.2 to get from kJ to kcal