Eating at least the recommended amount of whole grains may help lower your risk for health conditions such as cancer, heart disease, diabetes and obesity, according to an article published in "The Journal of Nutrition" in March 2011. Whole grains also provide more essential vitamins and minerals than refined grains, notes the Academy of Nutrition and Dietetics.

The U.S. Department of Agriculture recommends that half of the grains you eat consist of whole grains. This means women should eat at least three 1-ounce servings of whole grains per day, and men should eat three to four servings. A serving is equal to 3 cups of popped popcorn; 1/2 cup of cooked oatmeal, whole-wheat pasta or brown rice; a regular slice of whole-wheat bread; a cup of whole-grain breakfast cereal; a 6-inch whole-wheat tortilla; or half of a whole-wheat English muffin or mini bagel.