I would just say watch what you eat, by staying away from things like white bread.... sweets, and greasy foods.... but if you got by what you fitness plan and the nutritional plan say then just stick with it and you will loose the weight.... :) Just remember one thing... It took time to gain the weight it will take time to loose it as well...
-------------- God wont give you anything you cant handle!
I am not saying that you shouldn't exercise, participate in sports, and eat healthy, but be careful dieting at your age. You are 14, and your body is still growing. Some of that weight will be incorporated into your structure over the next few years as your shoulders fill out and you add muscle mass to your frame. Just eat healthy and remain active, and things should be looking up for you.