About kilojoules (kJ)
Just like kilometres are a measure of length, kilojoules are a measure of the amount of energy found in foods and drinks. Kilojoules are also the way we measure the amount of energy used in daily activities. Some foods and drinks have more kilojoules than others and knowing how many kilojoules are in different choices, will help you manage the amount of energy you take in.
The kilojoule value of foods and drinks varies depending on the amount of fat, carbohydrate, protein and water it contains. How many kilojoules you consume will also depend on the serving size of the food or drink.
Balance: energy in | energy out
We all need energy from food to keep our bodies working and for doing physical activities. Consuming more kilojoules than what the body needs each day can contribute to weight gain over time.
Maintaining a healthy weight means balancing how many kJ we eat and drink with the energy we use.
How many kilojoules you need in a day varies depending on a number of factors. For example:These groups are:
- You need more kilojoules if you are active and fewer if you don't do any regular physical activity
- You will need different amounts at different ages and stages of life and whether you are male or female, plus genetics also plays a role in determining your kilojoule needs
Knowing how many kilojoules are in the food and drinks you consume and being aware of how many kilojoules you need each day, can help you achieve balance in relation to your food and beverage intake and help you maintain a healthy weight.
How many kilojoules make a difference?
Reducing the kilojoules you eat and drink every day, or doing more exercise every day, can make a difference to your weight.
For example, reducing the kJ you eat and drink by just 100 kJ every day, or burning up an extra 100 kJ through exercise every day, can mean that you lose 1 kg of body fat after a single year.
You can achieve that by:
- Swapping a big food or drink serve for a smaller one
- Swapping a full fat for low fat or skim, or choose a muffin from our low-fat or gluten free range
- Swapping a high sugar food or drink for an artificially sweetened or 'low-cal' one
- Having fewer kJ at other meals
- Doing more activity when you eat more kJ it is recommended that adults do at least 30 minutes of moderate to vigorous physical activity most days
Total kJ each day
An average adult needs around 8700kJ daily to meet their needs. This is the total amount of kilojoules from all foods and drinks. Some people need less than this and others need more. To find out more about your daily energy needs, go to www.fastchoices.foodauthority.nsw.gov.au
You can use the average daily energy intake to guide how many kilojoules you consume each time you eat or drink during the day. By monitoring your intake, you can have more kilojoules at one meal and less at another to balance out your needs. The following two examples show different ways you can meet your energy needs over the day by spreading your kilojoule intake out.
We can use the average daily energy intake to help decide how many kJ we will consume each time we eat and drink throughout the day. If we have more kJ at one meal, we might have to have fewer kJ at another meal that day.
For more information & links to healthy eating sites visit: www.fastchoices.foodauthority.nsw.gov.au
Prepared in association with: NSW Food Authority & NSW Department of Health.