Your vehicle do need fuel to run. A good quality of fuel gives power to engine and longlife whereas a poor quality fuel makes the vehicle engine bad. The same story holds good for your body. Eat healthy food and not only the junk. You should have grains, fish, variety of fruits & vegetables. Eat more of green leafy salad. Your died should be full of vitamins and minerals too. Don\'t focus on low fat or low calories food only. Do focus on high vitamin, protein & mineral food.