Carbohydrates are the best source of food energy. These are broken down into a substance called glucose. The body cannot store large amounts of energy in the form of carbohydrates. As such, carbohydrate intake for an athlete is advised to be spread out over the course of a day. The understanding that pasta is good for an athlete stems from this scientific data.
Proteins are the last class of nutrients.
The need for these does not change dramatically with an increase in athletic activity. A healthy diet will include the four major food groups. These groups are milk, meat and high-protein fibers, fruits and vegetables, and cereal and grain foods. Each group provides different nutrients to an athlete's body. The milk group is a rich source of calcium.