Most of it is burned to keep your body temp up. The rest of it is to just do the basic functions, lungs, heart and organs working, the brain takes up a good chunk of energy as well.

Your right, you wont lose much weight by excercise unless you do it for many hours a day. You best bet is portion control, and eating less calorie dense foods, ie vegetables and fruits and natural meat instead of things with corn syrup, oils, butter, etc. its better to eat a giant bowl of spinich than it is like 1 slice of cheese.

The problem is our bodys have evolved to crave energy dense foods, so it basically means good tasting stuff is bad for you.