The Good Carbohydrates

(CBS)  Carbohydrates are no longer the enemy. They're actually an important part of a healthy diet, but only if you choose the right ones and in the right amount.

Elisa Zied, a registered dietician and spokeswoman for the American Dietetic Association joined The Early Show Thursday to shed some light on the carb debate. Zied is the author of a new book, "So What Can I Eat?!" which is the focus of a three-part HealthWatch series this week.

Half of your calories should come from carbs

"Carbs provide the body with glucose, which is the main fuel for the central nervous system, the brain," Zied told co-anchor Russ Mitchell. "You need it for energy. You don't want to eliminate or avoid it."

Carbs also provide the body with fiber, which fills us up and can help us manage weight and gastrointestinal health, among other things.

As always, portion size is critical.

"Moderation is boring, but it's the key," Zied said. "You need to watch your portion sizes and then you'll see you can fit a lot of these beautiful, wholesome, healthful and tasty foods into your diet."

Always choose whole grains

When you choose carbohydrate rich foods, you definitely want to emphasize whole grains over refined ones, says Zied. "Whole grains are much more nutrient dense and fiber rich than refined grains, like potato chips and things like that."

She says Americans currently consume about one whole grain food each day, so most people need to triple their intake. People who consume 2,000 calories a day should aim for at least three 1-ounce equivalents of whole grains. Below are some of Zied's recommended whole grain foods and the appropriate serving sizes.

Oat bran flakes: 1 cup
Oatmeal: 1/2 cup, cooked
1 slice whole wheat bread
1 whole wheat waffle
1/2 cup brown rice or wild rice, cooked
1 cup whole wheat pasta, cooked
a few whole grain/whole wheat crackers (100 calories worth)
3 cups air-popped popcorn

Eat raw fruits and vegetables

Many people don't realize that fruits and vegetables are loaded with carbohydrates, as well as other important vitamins and nutrients.

Zied recommends eating about two cups of fruit each day, in any combination of the one cup servings listed below.

1 small apple
1 large banana
1/2 cup dried fruit (like raisins or cranberries)
1 large orange
1 cup sliced strawberries
1 cup pineapple chunks

She recommends eating about 2 1/2 cups a day of vegetables, particularly the dark green, deep orange and yellow varieties, in combinations of the one cup servings listed below.

Green lettuces
1 cup broccoli, cooked
1 cup baby carrots, raw (about 12)
1 cup grape tomatoes
1 cup sliced red, green, yellow peppers (any combination)
1 large baked sweet potato

Tomorrow, in part three of this HealthWatch series, Zied shows how to fit proteins into your diet.

To read an excerpt from Zied's book, "So What Can I Eat?!" click here.