Eat LOTS of veggies, fruits, lean proteins, whole grains, and low fat dairy. Eat good sources
of fats such as
avocado, coconut, eggs, and nuts; avoid fried foods and foods high in saturated fat. You might also want to talk to your parents or dr about a multivitamin.
If you change your diet and activity level you should see some results or at least feel a difference. Keep in mind though miracles don't happen overnight.