The worst way to loose weight is actually cardio. If you want to become thin you want to stay away from cardio. The thing to do is actually weight-training. 1 pound of muscle burns 50 calories a day! Enough said
You burn calories, when you train using weights. When doing cardio you burn a lot of energy too, but you also break down muscle. Muscles are the number 1 energy-burner in your body. Hypothetically, you might burn 300 calories from one session on the treadmill or from running, but at the same time you have broken down muscle tissue, and therefore your body don't need the same energy it did before: you cannot eat as much on a daily basis as you did before the cardio.
Say you weight-train for 1 month and put on 5 punds of pure muscle. This means, you need 250 more calories a day to keep your energy balance. At the same time, as said, you burn calories when weight-training. If you manage to eat the same as you did before beginning the training, you lose weight. When doing cardio, you need to change your eating habits a lot in order to lose weight.
He he, this post is like "Blah blah blah", sorry about that, but to make it understandable: If you want to lose fat, stay away from cardio most of the time, instead begin training with weights. Just pm me, if you want me to make it more clear why that is