I think you are at a great age to decide to be fit. I encourage you to go along with it!! All you need to do is make sure you are a health weight. Not too thin, okay? Deciding to be fit now will help you make it a habit and increase the fitness in your future life! Go you!
Hi!
It is never too young to exercise. However, you cannot join a gym or do weight lifting etc yet until you reach 18 years of age. What you can do is take up a sport like tennis, badminton, cycling, swimming or a combination of these and train for these sports under a coach. These coaches help you go through stretches and other such exercises which tone up your body and make it supple. The sport itself helps you burn energy. Other than this, you need to go slow on junk food and incorporate a lot of fruits, vegetables, fiber, protein (egg, lean meat cuts etc) in your diet. Hope this helps. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.