When you or your child athlete thinks of food, you should think about carbohydrates, with the primary food sources being the whole-grain products, vegetables, and fruits that make up three quarters of the FDA's new MyPlate food guidance system. 
Studies have shown that adequate dietary carbohydrate must be consumed on a daily basis, especially after exercise, to restore levels of carbohydrates (glycogen) stored in the body's muscles and liver, which, as the preferred fuel for most types of exercise, is required for peak athletic performance.
- Only 46% of the typical American diet is derived from carbohydrates or about 2.2 grams per pound of body weight.
- Active children should get 50 to 55% of their total calories in the form of carbohydrates, or about 2.7 grams per pound of body weight.
- A child athlete who needs 2,500 calories per day thus needs to eat at least 313 to 343 grams of carbohydrate per day (there are 4 calories in 1 gram of carbohydrate).
- Most carbohydrates should be obtained from "complex" (starchy) carbohydrates found in vegetables, breads, cereals, pasta, and rice, rather than "simple" (sweet) carbohydrates found in milk and fruits. Although both simple and complex carbohydrates provide energy for working muscles, foods high in complex carbohydrates contain more essential nutrients, like B vitamins, iron, dietary fiber, and minerals, which are lacking in simple carbohydrates.
These guidelines for carbohydrate intake assume that the youth athlete is consuming adequate energy on a daily basis. Athletes who consume low-energy diets will slow the repletion of muscle and liver glycogen stores. This leads to fatigue, and may impair training and performance.
Low-energy diets are common among athletes such as gymnasts, figure skaters, wrestlers, and other athletes who traditionally maintain low body weights for appearance or performance. However, even during weight loss and energy restriction, a diet high in carbohydrate appears to be beneficial in helping athletes maintain high-intensity performance capacity.
The message from these studies is clear: not only is a diet high in nutrient-dense carbohydrates needed, but extra carbohydrate is beneficial as well. The fatigue and poor performance associated with glycogen depletion can be prevented by a carbohydrate-rich diet and with periodic rest days to give the muscles time to replenish the glycogen.
For a list of high-carbohydrate foods, click here.
Revised August 17, 2011
