How can i loose weight?

okay so i am 13 ,5'3 and i weight about 133 and i figure skate alot so that keeps me physicly active i also go to the gym every once and a while when i have time i don't have a great diet and i should probably eat more heathy foods but if any one could tell me a fast way to loose weight and it not being one of thoes crazy unhealthy diets that would be fab.