Crazy food cravings are a common experience among pregnant women, but having a well nourished baby means more than eating pickles and ice cream in those pre-birth months. Maintaining good nutrition, however, can be a challenge.

"It goes without saying that pregnant women must avoid alcohol, drugs and tobacco products," says registered nurse Ann Keppler, co-author of "The Simple Guide to Having a Baby" (Meadowbrook Press. $12, www.meadowbrookpress.com ), "but when it comes to food, many women feel that healthy eating during pregnancy means too many rules."

Eating right need not be so difficult, though, says Keppler, who counsels expectant mothers and those with young children about nutrition and feeding problems. "The best foods are whole foods, so a simple rule to remember is to shop in the outside aisles in the grocery store."

That's because the perimeter of the store is where fresh fruits and vegetables, meat and dairy products can be found, and when it comes to produce, think color.

"You should choose the most colorful vegetables you can find because they have the highest vitamin content," Keppler explains. For instance, "pink grapefruit is 50 times higher in vitamin A than white grapefruit, and did you know that sweet potatoes have far more nutrition than russet potatoes?"

The authors of "A Simple Guide to Having a Baby" provide this list of important foods to include in the daily diet:
- Fresh vegetables (4 servings)
- Fruits (3 servings)
- Whole-grain cereal and breads, tortillas or rice (9 servings)
- Dairy products that provide calcium: milk, cheese or yogurt (3 servings)
- Protein foods: meat, poultry, fish, nuts, eggs or beans (3 servings)
- Liquids: water (8 glasses) and milk or juice

Foods that are especially important for pregnant women are:
- Iron-rich foods: red meats (beef, pork), dark meats (turkey, chicken), and egg yolks
- Foods with some iron: prunes, beans, lentils, almonds, walnuts, dark green vegetables or blackstrap molasses
- A small amount of fat for cooking or adding flavor; oil (olive, canola or vegetable) or butter.

And what about fast food?

"Fast foods are not forbidden," Keppler says, "but choose them carefully. When you are in a fast food restaurant, choose broiled meats instead of the breaded and fried ones, and ask for your salad dressing on the side. And it's OK to have a diet Coke or Pepsi now and then, but not more than once or twice a day."

As for the ever-popular pizza, it is "not a terrible food either. It just depends on what proportion of your diet it is."

Keppler also cautions pregnant women to avoid large amounts of caffeine during pregnancy. Caffeine is found not only in coffee and caffeinated teas, but also in soft drinks, chocolate, and over-the-counter headache and cold remedies.

"Caffeine can change the baby's heart rate and may affect the mother's, too," she says. "It increases stress hormones, which cause the blood vessels to get smaller, which means less oxygen and nutrients get to the baby. This is why we recommend limiting caffeine drinks to one or two a day."

Pregnant women must also exercise caution when it comes to taking herbal and vitamin supplements.

"Some are helpful, but others may be harmful," Keppler says, and "the word 'natural' doesn't always mean safe." Mothers-to-be should avoid taking any supplements or herbal remedies without talking to their doctor."

In addition to this nutritional advice, "The Simple Guide to Having a Baby" has three chapters on pregnancy, four on birth and planning for the birth, and three on mother, baby and feeding.

The bottom line, Keppler says, is that "we're not asking a pregnant woman to completely change her diet, but we tell her that this is an opportunity to eat the best foods you can for you and your baby."

"The Simple Guide to Having a Baby" is a short, simple guide to pregnancy and is available wherever books are sold, or online at www.meadowbrookpress.com.

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