What is the recommended daily kilojoules intake for an adult?

It is very difficult to place a digit on how much energy one should consume daily as many lifestyle, age and genetic factors affect this however basically: the more active you are the more energy you need. I have put down a few numbers to give you some sort of a scale however it really depends on the individual. The way to fin out if you are taking in to much energy is to look down at your tummy and honestly use common sense (you don't have to be smart to tell whether you are fat). If you don't have enough time to exercise, make time or reduce the kilojoules. (I included a child to give a greater perspective).

Average adult: 8700 KJ

Overweight/less active: <8700

Elite Athlete: <1200 KJ

Child (8-10): 4700