Kilojoules, calories and the energy we get from food

Kilojoules (or kJ) are the measure of how much energy you get from food and drink. Some people also use the term ‘calories’ to describe this measure of energy. 


Getting enough energy and physical activity each day can help you stay healthy and reduce your risk of some diseases. It can also help you achieve and maintain a healthy weight. 

Your daily kilojoule needs 

Everyone is different and many things can influence your health. Knowing more about your energy needs is one way to support your health and wellbeing. This is because it can help you make healthier decisions about the kinds of food you eat and create habits that are right for you. 


On average, adults need 8700kJ a day from all foods and drinks. However, your personal daily kilojoule needs will depend on things like: 


  • how much physical activity you do, and what type  
  • your height, weight, age and sex 
  • whether you are pregnant or breastfeeding  
  • genetics and health. 

Getting too many or not enough kilojoules can affect your overall wellbeing, including your weight. For good health and wellbeing, the most important thing is to aim for a variety of healthy foods and get active every day if you can. 


Kilojoules and physical activity

Your body is using energy all day – even while you sleep. When you’re active, your body uses up more energy.  


But if you consume more kilojoules than your body uses, the spare energy can lead to weight gain. 


Regular physical activity can help you maintain a healthy weight and good health. It can also reduce your risk of chronic diseases and support your mental health.  


Learn more about how much physical activity to aim for to support good health and wellbeing. 


Find ideas for healthier meals at home in our healthy recipe library. 


Kids and kilojoules

Every child is different, so there is no exact number of kilojoules your kids should eat each day.  Your child's energy needs depend on how active they are, whether they’re having a growth spurt, and their age and sex. To help you work out which food and drink will support your child’s health, check out our Food Calculator. 


For ideas to help your kids stay healthy and thrive, check our guides on: 

You can also support your child by trying to build healthy habits into your day.

How to check the kilojoules in your food and drinks

The kilojoules in your food depend on its ingredients, how it has been prepared and its serving size. Most packaged foods and fast food outlets display kilojoules on packages and menus.  


Kilojoules are not the only thing to look for when you’re trying to make healthy choices. Something low in kilojoules might not be ‘healthier’ for you overall. For example, nuts are high in kilojoules but also have nutrients that support good health, so they are part of the 5 food groups. Diet soft drinks are low in kilojoules but don’t have any nutrients, so they’re not part of the 5 food groups. 


Here are some ways to help you make healthier choices around food and drinks. 


  • Try our food calculator to learn how many serves from each food group you should aim for each day.

  • Look for the Health Star Rating on packaged food and choose options with at least 3.5 stars. Vegetables and fruit may not have a package, but they score top marks – 5 stars. 

  • Learn how to read labels on packaged foods to check ingredients, kilojoules, and portion size. 

  • Look closely at the ‘number of servings’ on packaged food as the product package could have more than one serve in it. 

  • Remember, drinks contain energy (kilojoules) too. Some drinks are surprisingly high in kilojoules. But because they’re not as filling as food, we often don’t realise how many kilojoules we get from drinks. Alcoholic drinks are also high in kilojoules.  

Kilojoules and eating out

When you’re eating out, you might see kilojoules listed beside items on the menu. These can help you compare meals at takeaway stores and fast food and quick service restaurants. You can use this information to make healthier choices about what you eat and how often you eat it.  


The important thing is trying to eat a variety of healthy foods every day. When you’re eating out, try to limit ‘sometimes foods’ like fried foods, pastries and soft drinks. Instead, look for meals that contain foods from the 5 food groups. This will help you and your family stay healthy. 


Learn more about choosing healthier takeaway and homecooked meals and snacks. 

Get help to make changes

Kilojoule goals are a guide to help you understand your nutritional and physical activity needs. They shouldn’t be used in place of professional advice. Speak to your doctor or an Accredited Practising Dietitian for help with your health needs.  


You can also access free programs to help your whole family get healthier. 


Find free programs