Studies indicate that eating whole grains reduces your long-term risk of cancer and heart disease. On average, most school-age children need 6 to 8 ounces of grains a day and active teens may need as many as 9 or 10 ounces. (A slice of bread, a half-cup of cooked rice, pasta or oatmeal are examples of 1 ounce.) At least half of those servings should come from whole grains. The other half can come from enriched (e.g., refined or “white”) grains. Good whole-grain sources include whole-grain cereals, brown rice, whole-grain breads and whole-wheat pastas.