I play sports and excerise everyday! why am i gaining weight? and how can i lose it?

What are you eating?: You need a well-rounded plan that also addresses what your are eating, one that gives you high nutrient content (brightly colored fruits and vegetables) and not "empty" calories. You need to see a doctor, though, for a full medical evaluation to make sure you are healthy, and not gaining weight because of a thyroid problem, for example.

See physician: Exercising and playing sports will cause you to build muscle- which will cause you to weigh more, even as you slim down. Eating habbits can affect weight gain (smaller regular meals during the day are better than 1 big meal per day to lose weight). See your primary care doctor to make sure that you don't have a hormone imbalance causing the weight gain.