Just as your car performs better with premium gasoline, your body performs better when it's properly nourished. Your internal systems, such as your heart, lungs, and digestive tract, need the right fuel. This fuel includes a balance of fiber, carbohydrates, and protein.

Carbohydrates are your immediate source of energy. Carbohydrates that aren't immediately used by the body are stored in the muscles and liver as glycogen. Once the glycogen is used, the excess carbohydrates are stored in the body as fat. Carbohydrates should consume approximately 60 percent of your diet. Complex carbohydrates include foods such as whole grains, legumes, and potatoes.

Protein contains nutrients that are necessary for muscle formation and repair to damage from illness or surgery. Your protein needs depend on your activity level and body size.