Calories can be difficult to understand because you hear so many
different things from different sources. But here is the basic
idea: your body needs a certain amount of energy per day to
function properly .i.e. to digest food, walk, talk, exercise,
etc. The amount of energy your body needs depends on your
weight, age, gender, and how active you are. We get calories
from food, and through metabolism, these calories are converted
into energy. So the amount of energy your body needs is directly
proportionate to how many calories you need. If you consume more
calories than your body needs, your body stores the excess as
fat. When you work out, you burn the excess calories; which
means you are essentially burning off the fat. This is how you
maintain your body fat ratio. This is why it’s important to
understand that there's no magical way to lose weight. It comes
down to two things: exercise and diet. To lose weight, you have
to burn more calories than you take in every day. Visit
http://caloriecount.about.com/cc