Energy is required by the body for growth and repair, body functions and physical activity. The energy we consume keeps everything in the body working: the heart beating, the brain thinking and the legs running.
Every person requires different levels of energy intake dependent on their body weight and their level of activity, as well as their age, gender and individual body requirements.
On food packaging, energy will be listed as kilojoules (kJ) or calories (cal). These are the terms used for measuring energy. One calorie equals 4.3 kJ. It is important to take note of the amount of energy present in a food to help determine how much of a food you should eat.