Eating well during pregnancy is not just about eating more. What you eat is as important.

If you are carrying one baby, you need just 340–450 extra calories a day — and this is later in your pregnancy, when your baby grows quickly. This isn't a lot — a cup of cereal and 2% milk will get you there quickly. What’s important is to make sure that the calories you eat come from nutritious foods that will help your baby's growth and development.

Nutrition for Expectant Moms

A healthy diet includes proteins, carbohydrates, fats, vitamins, minerals, and plenty of water. The U.S. government's dietary guidelines can help you build a healthy eating routine when you’re pregnant. They also offer a tool that can help you figure out how many servings of each kind of food to eat every day based on your age, physical activity level, stage of pregnancy, and other factors. Eating a variety of foods in the proportions indicated is a good step toward staying healthy. Talk to your doctor about building a plan that works for you.

Important Nutrients During Pregnancy

Your diet can affect your baby's health — even before you become pregnant. For example, research shows that folic acid, a type of B vitamin, helps prevent neural tube defects (including spina bifida) during the earliest stages of fetal development. So it's important to get plenty of it before you become pregnant and during the early weeks of your pregnancy. Foods that contain folate (the form of the vitamin found naturally in foods) include green leafy vegetables; nuts; and legumes such as beans, peas, and lentils.

Doctors encourage women to take folic acid supplements before and throughout pregnancy (especially for the first 28 days). Be sure to ask your doctor about folic acid if you're considering becoming pregnant.

Calcium is another important nutrient. It helps build strong bones and teeth, and plays an important role in helping the circulatory, muscular, and nervous systems work properly. Your best food sources of calcium are milk and other dairy products. If you have lactose intolerance or dislike milk and milk products, ask your doctor about a calcium supplement. Other calcium-rich foods include sardines or salmon with bones, tofu, broccoli, spinach, and calcium-fortified juices and foods.

Doctors don't usually recommend starting a strict vegan diet during pregnancy. But if you already follow a vegan or vegetarian diet, you can continue to do so, but do it carefully. Tell your doctor about your diet. It's challenging to get the nutrition you need if you don't eat fish and chicken, or milk, cheese, or eggs. You'll likely need supplemental protein and may also need to take vitamin B12 and D supplements.

Other important nutrients include iron (in meats and poultry, dark green vegetables, and legumes), iodine (in seafood, eggs, and dairy products), and choline (in meats, eggs, and legumes). Sometimes it’s hard to get enough of these from the food we eat. That's why doctors often recommend a daily prenatal vitamin.

Food Cravings During Pregnancy

Craving specific foods during pregnancy is common. Some pregnant women crave chocolate, spicy foods, fruits, and bland comfort foods. Others crave non-food items, such as clay and cornstarch. The craving and eating of non-food items is known as pica. Consuming things that aren't food can be dangerous to both you and your baby. If you have urges to eat non-food items, tell your doctor.

Otherwise, following your cravings is fine if you crave foods that contribute to a healthy diet. Often, these cravings let up about 3 months into the pregnancy.

What Food and Drinks Should I Avoid While Pregnant?

Besides getting the right amounts of healthy foods during pregnancy, it's also important to know what food and drinks to avoid. For instance:

• No level of alcohol consumption is considered safe during pregnancy. 
• Check with your doctor before you take any vitamins or herbal products. Some can harm a developing fetus.
• It's probably wise to avoid caffeine altogether if you can, though many doctors feel that one or two 6- to 8-ounce cups per day of coffee, tea, or soda with caffeine won't harm your baby. High caffeine consumption, though, has been linked to an increased risk of miscarriage and other problems. Try to limit your intake or switch to decaffeinated products.
• Avoid food-borne illnesses, such as listeriosis and toxoplasmosis, which can be life-threatening to an unborn baby and may cause health problems or miscarriage.

If you've had some risky food or drinks at some point during your pregnancy, try not to worry too much about it now. Just avoid them for the rest of the pregnancy. If you're really concerned, talk to your doctor.

Is it OK to Eat Fish While I'm Pregnant?

Fish and shellfish can be a healthy part of a pregnancy diet because they contain beneficial omega-3 fatty acids and are high in protein and low in saturated fat. But avoid the kinds that can have high levels of mercury (such as shark, swordfish, king mackerel, tilefish, orange roughy, and bigeye tuna), which can damage the brain of a developing fetus. 

If you eat seafood, choose a variety of fish and shellfish and limit the amount to about 12 ounces per week — that's about two meals. Common fish and shellfish that are low in mercury include catfish, pollock, clams, tilapia, salmon, and shrimp.

What about canned tuna? Reports vary, but because some indicate that amounts of mercury may be higher than previously reported, you might want to skip tuna while pregnant or when trying to become pregnant.

If you eat fish caught in the wild by friends or family, limit it to one serving and don’t eat any other fish that week because you don’t know how much mercury might be in the caught fish.

Talk with your doctor if you have any questions about how much — and which — fish you can eat. You also can check the FDA's site about eating fish during pregnancy.

Dealing With Constipation, Gas, and Nausea

Constipation

The iron in prenatal vitamins and other things can cause constipation during pregnancy. So try to get more fiber than you did before you became pregnant. Try to eat about 20–30 grams of fiber a day. Your best sources are fresh fruits and vegetables and whole-grain breads, cereals, or muffins.

Check with your doctor before trying any fiber tablets or drinks or other high-fiber products. (Don't use laxatives while you're pregnant unless your doctor advises you to do so. And don't use castor oil because it can make your body less able to absorb nutrients.)

If constipation is a problem for you, your doctor may prescribe a stool softener. Be sure to drink plenty of liquids, especially water, when increasing fiber intake, or you can make your constipation worse.

One of the best ways to avoid constipation is to get more exercise. Drink plenty of water between meals each day to help soften your stools and move food through your digestive system. Sometimes hot tea, soups, or broth can help. Also, keep dried fruits handy for snacking.

Gas

Some pregnant women find that broccoli, spinach, cauliflower, and fried foods give them heartburn or gas. You can plan a balanced diet to avoid these foods. Carbonated drinks also cause gas or heartburn for some women, although others find they calm the digestive system.

Nausea

If you're often nauseated, eat small amounts of bland foods, like toast or crackers, throughout the day. Some women find it helpful to eat foods made with ginger. To help combat nausea, you can also:

• Take your prenatal vitamin before going to bed after you've eaten a snack — not on an empty stomach.
• Eat a small snack when you get up to go to the bathroom early in the morning.
• Suck on hard candy.