10 Nutrition Do's and Don'ts During Pregnancy

Which foods should you avoid, and how long can a pregnant person go without eating? Get answers to all your questions about prenatal nutrition.

pregnant woman eating peanut butter
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There are a dizzying number of do's and don'ts during pregnancy, especially when it comes to what you should eat. But you can actually eat a lot more freely than you might imagine.

In fact, variety is encouraged, as it's important to load up on key nutrients that you and your growing baby need. Additionally, a pregnant person shouldn't go too long without eating to maintain their energy. So, be sure to eat when hungry and avoid fasting while pregnant.

That said, certain foods and eating patterns can compromise fetal development, and every parent-to-be should know about them. Research shows that many pregnant people do not meet recommended dietary guidelines. So, focus on nutrient-rich foods and healthy habits that will keep you and your baby thriving for nine months.

Read on for the lowdown on nutrition do's and don'ts during pregnancy.

Do Load Up on Folate, Calcium, Iron, Zinc, and Fiber

With all the focus on what pregnant people can't do, such as drink alcohol or eat sushi, it's easy to forget that there are lots of pregnancy nutrition do's as well. Getting enough nutrients to support your body and your growing baby is by far one of the most important. Here are the essential nutrients to put on your plate.

Folate

Before conception and in the first six weeks of pregnancy, no nutrient is more vital than folate (more commonly known as folic acid, the synthetic form). This B vitamin can reduce the risk of neural-tube defects, such as spina bifida, by a whopping 92%. Preventing neural-tube defects is one reason prenatal vitamins are so important, especially in the early weeks of pregnancy.

You can also get your daily minimum of 400 micrograms (600 micrograms is recommended in the first trimester) from the following foods:

  • Beans and legumes
  • Citrus fruits and juices
  • Whole grains
  • Dark green leafy vegetables
  • Poultry
  • Pork
  • Fish
  • Shellfish

Folate from foods is sometimes not as well absorbed as supplemental forms, so pop a prenatal vitamin for insurance.

Calcium

You should get around 1,000 milligrams of calcium a day, according to the U.S. Department of Agriculture (USDA). This nutrient plays a vital role during the second and third trimesters when your baby's bone and tooth development peaks. Optimal sources include the following:

  • Low-fat dairy products
  • Dark green vegetables
  • Fortified plant milk products
  • Soy products like tofu

Adequate calcium also plays a role in preventing preterm birth and preeclampsia.

Iron

Iron, necessary for supporting your 50% increase in blood volume, is crucial in the third trimester. Aim for 27 milligrams per day. To boost iron absorption, combine iron-rich foods, such as nuts, red meat, and dark leafy green vegetables, with sources of vitamin C, such as citrus fruits.

"Iron is difficult to get from the diet, so take an iron supplement or prenatal vitamin with iron," advises Hope Ricciotti, MD, associate professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School and co-author of I'm Pregnant! Now What Do I Eat?.

Zinc

The USDA recommends 11 milligrams of zinc per day when you're pregnant. Research has found that zinc deficiencies in pregnancy have been linked with the following:

  • Low birth weight
  • Preeclampsia
  • Prolonged labor
  • Postpartum bleeding
  • Delayed neurobehavioral development
  • Delayed immune system development
  • Birth defects
  • Restricted fetal growth
  • Premature delivery

Although nuts, whole grains, and legumes are good sources, the mineral is best absorbed from meat and seafood.

Fiber

Fiber (found in fruits, vegetables, and whole grains) is particularly essential for your own health. It helps prevent or reduce constipation, a common pregnancy complaint that can lead to uncomfortable bowel movements and hemorrhoids.

Eating a fiber-rich diet also helps you feel fuller longer. Additionally, adequate fiber intake lowers the risk of diabetes and preeclampsia. Aim for 25-35 milligrams a day. 

Do Eat a Rainbow of Foods

A varied diet provides you and your baby with all the important nutrients. In addition, an eclectic mix also introduces your little munchkin to new tastes via the amniotic fluid.

Of course, if bananas and saltines are the only foods you can stomach in the first trimester, that's fine! Your baby will have plenty of opportunities to experience different foods once they are born.

"But as soon as you start feeling better, aim for more variety," says Orlando-based nutritionist Tara Collingwood, MS, RD. Deep-hued fruits and vegetables, such as blueberries, carrots, and spinach, are the richest in antioxidants and other nutrients.

Do Limit Your Exposure to Pesticides

Choose organic and locally grown foods when possible to avoid exposure to pesticides. "The developing immune system is so much more sensitive than the adult's," says Rodney Dietert, PhD, professor of immunotoxicology at Cornell University's College of Veterinary Medicine, whose research has linked prenatal pesticide exposure to later-in-life immune dysfunctions.

According to the Centers for Disease Control and Prevention (CDC), exposure to pesticides in pregnancy increases the chance of the following:

  • Miscarriages
  • Birth defects
  • Learning or developmental disabilities in children

"We have a lot of evidence now that nitrates [chemicals used in fertilizer] and pesticides have the ability in very small doses to interact with the hormonal milieu of the pregnancy," says Paul Winchester, MD, a clinical professor of pediatrics at the Indiana University School of Medicine.

Washing your produce helps, says Dr. Winchester, but that step may not be enough to eliminate contamination. The produce harboring the highest pesticide concentrations tend to be fruits and vegetables with thin skins, such as peaches, apples, bell peppers, and strawberries. Also, foods imported from other countries, such as Mexico or Chile, may contain pesticides prohibited in the U.S.

Do Get Your Omega-3 Fatty Acids

A diet rich in omega-3s can boost your baby's neurological and brain development before birth. Omega-3s may offer the following benefits:

  • Better childhood vision
  • Better childhood memory
  • Better language comprehension in early childhood
  • Reduced risk of postpartum depression

Flaxseed oil, walnuts, and omega-3-fortified eggs are good sources of ALA, one of the three omega-3 fats. But fatty fish are the only reliable sources of the two more critical omega-3s, EPA and DHA, according to Dr. Ricciotti. It's recommended that pregnant and lactating people get at least 300 milligrams of DHA in their daily diet.

The trick is to choose fish high in omega-3s but low in mercury, which can harm a fetus's nervous system. Varieties to avoid include swordfish, shark, king mackerel, tilefish, and some experts now say tuna, though canned light tuna is safer than albacore.

Top picks include wild Alaskan salmon (fresh, frozen, or canned), Atlantic mackerel, herring, sardines, and anchovies. Fish oil supplements are also safe.

Do Choose "Double Duty" Food

Pick foods that pack a variety of benefits. "Nutrient-dense foods, such as yogurt, peanut butter, chicken, beef, eggs, and dairy products, are those that are higher in protein, calcium, and iron, all nutrients your baby needs to grow and develop properly," says Rose Ann Hudson, RD, LD, co-author of Eating for Pregnancy: An Essential Guide to Nutrition With Recipes for the Whole Family.

Some other nutrient-dense foods include lean pork, which, like beef, contains protein and B vitamins, iron, and zinc. Orange juice offers folate plus vitamin C, which helps you absorb iron from foods such as fiber-rich black beans and spinach. Whole grains contain fiber, B vitamins, magnesium, and zinc.

Don't "Eat for Two"

While it's understandable to love the idea of "eating for two," the concept is a misnomer. The majority of pregnant people gain more weight during pregnancy than recommended.

In fact, one study of over 8,000 participants found that 73% had gained more weight than recommended. Excess prenatal weight gain increased the risk of pregnancy complications like hypertension, delivering a large for gestational age baby, and C-section. Plus, "the babies have a higher risk of obesity later in life," says Dr. Ricciotti.

Ideally, weight is gained slowly and steadily throughout pregnancy, and health care providers will base your pregnancy weight-gain goal on your height and pre-pregnancy weight. The range is between 20 pounds for people who have obesity and up to 40 pounds for underweight people. You'll need to gain a bit more if you're expecting multiples. Consult with a health care provider about how much weight you should aim to put on.

If you're carrying a single baby, you need approximately 300 extra calories daily starting in the second trimester. But rather than count calories, simply eat until you feel satisfied. If you struggle with portion control, seek the guidance of a registered dietitian.

Don't Go Heavy on Refined Carbs

Refined carbohydrates like those in white bread, white rice, sweets, and sodas rush into your bloodstream, spiking your blood glucose levels. These spikes may result in bigger newborns, who are at greater risk of being overweight as they grow up.

"If you consume the same number of calories but just change what you eat, your baby may have less body fat at birth and a lower risk of future obesity," advises Dr. Ricciotti. Limit the white stuff and opt for unrefined whole grains such as steel-cut oats, brown rice, quinoa, whole-wheat tortillas, and whole-grain bread.

Don't Overlook Food Safety

Be aware of food safety practices to protect yourself and your baby from harmful bacteria such as E. coli, Salmonella, and Listeria. "Don't eat raw or undercooked meat, poultry, seafood, or eggs, and don't eat leftover food that has been sitting out for more than two hours," says Gidus.

Also, the following tips may reduce your risk of foodborne illness:

  • Stick a thermometer in your refrigerator to ensure the temperature is below 40 degrees, which is cold enough to stop bacteria from growing.
  • Heat deli meats until steaming hot.
  • Check the labels of soft cheese, like brie and blue cheese, to ensure they are made with pasteurized milk.
  • Avoid sushi with raw fish and stick to those that are vegetarian or contain cooked fish.

Unpasteurized soft cheese can harbor Listeria, which can lead to premature delivery, miscarriage, or stillbirth. If there's no label, don't take the chance.

Don't Go More Than 2 or 3 Hours Without Eating

So, how long can a pregnant person go without eating? The answer is to eat at least every three or so hours. Grazing not only pumps a steady stream of nutrients to your baby but also keeps your blood sugar levels steady so you don't "crash" or become lightheaded.

"If you don't fill the tank frequently, you can bottom out," says Dr. Ricciotti. Smaller meals also minimize heartburn, a common and painful problem as pregnancy progresses and your stomach gets squeezed. So, keep some nutritious snacks around for between-meal munching.

Don't Forget to Hydrate

Drink your water! "It's hard to stay hydrated when you're pregnant because a lot of the fluid you drink leaks from your blood vessels into your tissues," explains Dr. Ricciotti. Yet, hydration is essential for maintaining energy and preventing preterm labor. Being dehydrated can lead to contractions.

Staying hydrated also helps prevent headaches, kidney stones, dizziness, and common pregnancy complaints such as constipation and hemorrhoids. You know you're well hydrated when your urine is light yellow to clear.

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Sources
Parents uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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