Most women understand that when they become pregnant, their diets may need to change. But, exactly what that means — beside skipping the wine and raw sushi, craving pickles and ice cream, and “eating for two” — often remains foggy.
So how should pregnant women make healthy decisions about their diet to support a healthy pregnancy and a healthy child? Here, I outline some of the more important nutritional factors to consider when determining how to eat during pregnancy.
(As a reminder, please check with your doctor before making any changes, and consider working with a registered dietitian for personalized recommendations.)
Why Nutrition Is So Important During Pregnancy
“You are what you eat!” You’ve probably heard that phrase before, but did you know a child’s lifelong health is also strongly dictated by how the mother ate during pregnancy? Malnutrition, stress, toxin exposure, and illness during pregnancy can affect the health of the baby for the rest of his or her life.
Not only does your nutrition affect your baby’s growth and development over the course of nine months, but it also affects the expression of certain genetic programming passed on through your DNA. This is known as “epigenetics” — the power of our environment to actually change how our permanent DNA code is used in the real world.
What’s more, your nutritional intake during pregnancy can greatly affect your own health. What you eat before getting pregnant affects your fertility, and what you eat while pregnant can affect your health risks during pregnancy. Following a healthy diet can also help reduce the risk of common pregnancy-related conditions such as preeclampsia, nausea, constipation, gestational diabetes (which can increase your risk of developing Type 2 diabetes later in life), and more.
Fortunately, there are plenty of simple things you can do to make sure your baby gets the nutrition needed to thrive, and that your pregnancy is as healthy and stress-free as possible.
Eating for Two?
While calorie needs will increase throughout the three trimesters depending on a woman’s weight gain needs and pre-pregnancy body mass index (BMI), she’s not truly “eating for two” during her pregnancy. The Academy of Nutrition and Dietetics recommends the following general guidelines for calorie increases per trimester :
- First trimester: no required extra calories
- Second trimester: approximately 340 calories a day above baseline needs
- Third trimester: approximately 450 calories above baseline needs
This means that a woman who needs to eat 2,000 calories per day to maintain her weight prior to pregnancy will need to eat about 2,340 calories per day during her second trimester and about 2,450 during her third.
Keep in mind that these are rough estimates, and an individual woman’s intake will vary from day to day. Also, remember that baseline calorie needs in general — pregnant or not — may be a lot higher than some people realize. Check out this article to learn more.
Another factor influencing your calorie needs during pregnancy are your weight gain goals. Your doctor will make specific recommendations for weight gain, but generally the guidelines are as follows for a single pregnancy :
- BMI <18.5: Gain 28 to 40 pounds
- BMI 18.5-25: Gain 25 to 35 pounds
- BMI 25-30: Gain 15 to 25 pounds
- BMI >30: Gain 11 to 20 pounds
If your BMI before pregnancy is less than 18.5 or greater than 30, there are increased risks of birth complications, preterm delivery, and birth defects. Ideally, you should aim to be between 18.5 and 30 before getting pregnant, but these weight-gain guidelines can help reduce the risk of complications for mothers whose BMI is below 18.5 or above 30.
Keep in mind that no matter your weight pre-pregnancy, no woman should be losing weight while pregnant. Some women lose a little weight in the first trimester if they’re dealing with severe nausea, but otherwise all women should seek to gain the appropriate amount of weight during their pregnancy.
Unfortunately, a pregnancy-related restrictive eating pattern has emerged as a growing number of pregnant women are purposefully restricting calories to avoid weight gain during pregnancy. (You might see this referred to as “pregorexia” in the media, but that is not a recognized clinical term). Dealing with weight gain during pregnancy can be emotionally tough for many women, especially when there is a past history of disordered eating. Please seek professional guidance if you have any thoughts or behaviors around restrictive dieting during your pregnancy.
What About Macros?
A fair bit of controversy exists around macronutrient needs for pregnant women. Some women are choosing to go vegan, vegetarian, low-carb or even ketogenic while pregnant. While there may be special circumstances in which a more extreme diet could be recommended for during pregnancy, this article will focus on generally accepted guidelines for pregnancy.
Protein needs are slightly higher during pregnancy. Dietary protein provides vital structural proteins that form the building blocks necessary for the healthy development of your baby — collagen, elastin, muscle, tendons, enzymes, everything. For this reason it is critical to get into the habit of eating enough protein early in your pregnancy.
The National Institute of Health (NIH) recommends a minimum of 71 grams of protein per day during pregnancy, compared to the 46 grams minimum for the average woman . That’s a daily increase of 25 grams of protein, which you find in about four ounces of meat (a palm-size serving) or a cup of plain Greek yogurt, for example.
These guidelines are a minimum, however, and most women (particularly active women) can benefit from higher amounts of protein. To determine how much protein you really need, check out this article. Keep in mind that any deficiency in calorie intake can lead to protein deficiency during pregnancy, so don’t skimp on your calories, regardless of your protein consumption.
Most women develop some protein aversion during pregnancy, so it can take a little more effort than normal to hit a higher protein goal. While eating enough protein is important during pregnancy, there’s no need to overdo it, and excessive protein consumption could have adverse effects on your baby’s health [4, 5, 6]. Sticking with three to four palm-sized servings of protein per day should be enough for most pregnant women. As stated earlier, it is always best to consult with your healthcare provider or a registered dietitian for more individualized guidance.
Ideally your protein intake should consist primarily of complete proteins from animal sources, however if you’re vegetarian you need to ensure that your foods are properly diversified to provide all essential amino acids. You can learn more about diversifying your protein sources here.
Fat is an important source of calories and vitamins during pregnancy, so don’t avoid it. The NIH recommends that at least 20 percent of a pregnant woman’s daily calories should come from fat . For a woman eating 2400 calories per day, this would be around 54 grams of fat per day.
Fat-containing animal-based foods such as egg yolks, milk, yogurt, butter, and grass-fed meats are great sources of nutrients essential for optimal fertility and a healthy pregnancy. A slightly higher fat intake than the bare minimum requirements provides higher amounts of the fat soluble vitamins that are so important for fetal development. Learn more about dietary fat recommendations here.
Essential fatty acids, particularly omega-3 fats such as DHA and EPA, are crucial during pregnancy as well. Pregnant women should aim to eat 1.4 grams per day of omega-3 fats, and try to limit their intake of omega-6 rich seed oils to keep their omega-3-to-omega-6 ratio lower than 1:5 .
Carbohydrates may be the most controversial macronutrient for pregnant women. The recommended dietary allowance (RDA) is set at a minimum of 175 grams per day (versus 130 grams per day for non-pregnant women), and generally low-carbohydrate diets are not recommended during pregnancy.
However, there are many nutritionists support the use of low-carb diets during pregnancy, particularly for women at higher risk for gestational diabetes.
According to the NIH, identifying with one or more of the following increases a woman’s risk for gestational diabetes:
- Being very overweight
- Currently having diabetes or having a family history of diabetes
- Being Hispanic/Latina, African American, American Indian, Alaska Native, Asian American or Pacific Islander
- Being older than 25
- Having one of the following in a previous pregnancy: gestational diabetes, stillbirth or miscarriage, large baby weighing more than nine pounds
- Having PCOS or another health condition linked to problems with insulin
- Having ever had problems with insulin or blood sugar, such as insulin resistance, glucose intolerance, or “pre-diabetes”
- Having high blood pressure, high cholesterol, or heart disease
If you know you’re at higher risk for gestational diabetes, or you’ve had gestational diabetes in prior pregnancies, it’s possible that a lower carbohydrate diet could work well for you. If you do intend to consume a very low carbohydrate diet (fewer than 150 grams of carbs per day) during pregnancy, I’d strongly suggest enlisting the guidance of a registered dietitian who can assist you with planning an appropriate low-carb diet.
My philosophy is that, while lower carbohydrate diets are unlikely to be “dangerous” during pregnancy, for most women they’re neither necessary nor beneficial, especially for active women.
For most women who are active and have good blood sugar control, I’d suggest a carb intake of somewhere around 40 percent of total daily calories, ideally coming from whole rather than refined and processed foods. For a woman eating 2400 calories per day, that is 240 grams. To learn more about carbohydrates, check out this three-part series here, here, and here.
Does It Fit Your Micros?
One problem with overemphasizing macronutrients like protein, carbs, and fat is that it can cause us to forget about the many micronutrients that are necessary for optimal health, particularly during pregnancy.
There are several nutrients of concern that women must consume in adequate amounts (i.e. higher amounts than pre-pregnancy). Many of these are contained in high-quality prenatal vitamins, but it’s important to prioritize them (and others) in your diet.
Here are the most important ones, and the best ways to get them:
- Choline: egg yolks, liver, cauliflower, peanuts
- Vitamin A: liver, egg yolks, carrots, sweet potato
- Vitamin D: sunlight, mushrooms, fortified dairy
- Vitamin K2: Fermented foods, gouda cheese, natto
- Calcium: Dairy products, bone-in canned fish, leafy greens, nuts, seeds
- Folate: Liver, leafy greens, lentils, beans, green leafy vegetables
- B12: Liver, seafood, red meat, eggs
- Iron: Liver (sensing a pattern here?), red meat, poultry, beans
- Magnesium: dark leafy greens, nuts and seeds, fish, beans, avocados, yogurt, bananas, dried fruit, dark chocolate
- Zinc: Shellfish, pumpkin seeds, red meat, poultry, spinach
- Iodine: Seaweed, seafood, shellfish, dairy, eggs
As you can see, liver is a nutritional powerhouse. Aim to eat about three to four ounces per week during pregnancy, but no more than a pound per month unless specifically instructed by your personal doctor to do so. Liver is high in vitamin A, which, in significant excess could increase your baby’s risk of birth defects.
When considering seafood, keep in mind that older, larger fish such as swordfish, shark, king mackerel, and tilefish tend to have a higher mercury content. Tuna is also a concern, and pregnant women should limit servings of tuna to no more than two cans per week, choosing chunk light instead of white tuna.
The Environmental Protection Agency states that it is safe for pregnant women to eat up to eight to 12 ounces of fish or seafood low in mercury per week (or approximately two meals). Safe selections include shrimp, salmon, pollock, catfish, anchovies, and trout .
Nausea and vomiting affect 70 to 80 percent of all pregnant women . As uncomfortable as it is, take solace in the knowledge that nausea and vomiting during pregnancy is completely normal to experience and is even associated with better pregnancy outcomes (who knew?)
One downside to nausea during pregnancy is that it can make healthy eating — or eating at all — quite challenging.
A few tips for getting the nutrition you need while minimizing nausea include sticking to bland foods as much as possible, minimizing the amount of spices and seasonings in your food, and eating starchy foods such as rice, bananas, bread, or potatoes. Eating smaller, more frequent meals can help reduce some of the nausea experienced when your stomach is empty.
Two supplements that are helpful for nausea are ginger and vitamin B6. Ginger can be taken as a pill, drunk as a tea, or eaten whole (candied ginger is particularly palatable), and is a safe and effective nausea-reducer for pregnant women . Vitamin B6 is another effective supplement for reducing nausea and vomiting in pregnancy, with doses between 30 to 40 mg per day recommended for pregnant women .
Time to Eat!
While the goal of the tips in this article is to empower you to optimize your health and nutrition during pregnancy, it’s important to remember that these guidelines can also help women prepare their bodies for pregnancy.
Don’t forget to enjoy your food, listen to your body, and, if a craving strikes, have some ice cream and pickles!
- Wolfram, T. Healthy Weight during Pregnancy. Eat Right Academy of Nutrition and Dietetics. February 22, 2017.
- Weight Gain During Pregnancy. American Congress of Obstetricians and Gynecologists. Number 545. January 2013. Reaffirmed 2016.
- Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Total Water and Macronutrients. Food and Nutrition Board, Institute of Medicine, National Academies. Washington (DC): National Academies Press (US); 2011.
- Herrick K et al. Maternal consumption of a high-meat, low-carbohydrate diet in late pregnancy: relation to adult cortisol concentrations in the offspring. J Clin Endocrinol Metab. 2003 Aug;88(8):3554-60.
- Campbell DM et al. Diet in pregnancy and the offspring’s blood pressure 40 years later. Br J Obstet Gynaecol. 1996 Mar;103(3):273-80.