what is kj and kcal

[tryme]

its quite simple really. whats the difference and more importantly what should I be looking at in terms of nutritional information.

[Mercuryblade]

They are both units of energy.
KJ stands for Kilojoules and Kcal stands for Kilocalories also known as a Calorie with a capital "C".

The second part of your question is too broad and I have no idea what you are asking.

[tryme]

whats more important when trying to meet your needs.

[Mercuryblade]

They are units of energy, the difference between the two is just a unit conversion. Think centimeter vs inch.
Every kilocalorie (aka Calorie) is 4.184 kJ (kilojoules).