If you do not exercise then yu can forget getting into shape properly. If you want to lose 15-20 pounds that you don t sound like you need to lose, then just go on a starvation diet and ruin your health. You could begin to eat healthier-losts of veggies and fruit and only whole grains and such, and just walk more than you do. Plop on your mp3 and walk a little quicker than you usually do for 30 minutes every other day. You don t need to lose 20 pounds. In fact, if you lose too much weight you can really screw up your kidneys and liver, not to mention heart problems. But you are 13, and you are going to listen to the fashion world and be all paranoid and image conscious, so knock you socks off. Too bad you, because your problem(s) is (are) not your weight chances are.
that is average weight at school i am about the same and they say that thats underweight so you dont need o lose ne weight