I know it might seem obvious — but working out is good for you! I just read a great article/study in the NY Times and I want you to read it. NY Times article
In short, exercise increases your body’s ability to metabolize fat (both immediately and over time) and lowers your levels of fatty acids and blood sugars. Obviously the more fit you are, the better your metabolism is. And this doesn’t mean you have to be a marathoner. Just move your body with intensity every day. Couple this with a diet rich in low fat protein, good carbohydrates, and an abundance of fruits and vegetables and you are on your way to a lifetime of health.