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The Do's and Don'ts of Pregnancy Nutrition

The Do's and Don'ts of Pregnancy Nutrition

Reading Time: 5 minutes 33 seconds


DATE: 2018-09-07

Working with pregnant clients can be daunting. You want to make sure she is able to keep up with fitness, but you also need to strike a balance and help her avoid overdoing it or getting injured.

As a trainer, you have a responsibility to help your pregnant clients work out effectively and safely but also to help guide her nutrition.

Always encourage clients with special needs to consult with their doctors or registered dieticians if they have concerns about food. But, also be there to educate them and help them make better choices about what they eat.

Do Eat More and Gain Weight

For your fit moms-to-be, the idea of gaining weight can be tough to swallow. But impress upon them how important it is—for their health and that of their unborn babies—to take in more calories and add extra pounds.

Recommendations for weight gain are that women gain one to four pounds during the first trimester, and then about one pound per week during the second and third trimesters. (1)

Clients can also search for a pregnancy weight gain calculator online. Based on height and weight before pregnancy it will tell a woman how much she should gain in total. Generally, though, it breaks down like this:

  • Women who are underweight need to gain 28 to 40 pounds during pregnancy.

  • Those who are overweight should gain between 15 and 25 pounds.

  • Women who are shorter than five feet, three inches, should gain between 10 and 25 pounds, depending on pre-pregnancy weight.

Do Increase Calcium and Vitamin D Intake

Vitamin D and calcium go together like peanut butter and jelly, and pregnant women need to get enough of both to help prevent preeclampsia. Inadequate calcium levels can trigger this dangerous condition that leads to high blood pressure. And vitamin D is needed for proper absorption of calcium.

Your pregnant clients can get plenty of vitamin D by being out in the sun for just 20 to 30 minutes a couple of times a week. If she is particularly conscious of avoiding the sun for skin health, she can get enough through fortified foods, mostly milk, milk substitutes like almond milk, and cereals.

Calcium can be found in fortified foods too, but also in leafy green vegetables, legumes, nuts, seeds, figs, and tofu.

During pregnancy, women should include about 1,000 milligrams of Calcium per day and 600 international units of vitamin D. (2)

Learn more: Should pregnant women give it their all during workouts?

Do Get More Iron, Zinc, and Vitamin B12

Other minerals that are crucial during pregnancy include zinc and iron. Iron plays a big role in many of the biological processes going on as a baby develops in the womb because it is essential for making red blood cells and carrying blood to the fetus.

Zinc is also needed during fetal development, and a deficiency in this mineral can increase the risk of congenital birth defects. Vitamin B12 helps promote cell development, crucial for a growing baby.

Most women who eat a typical diet with meat and other animal foods will not have a problem getting enough of these three nutrients. But those who are vegan or vegetarian may need to make some dietary changes to ensure they take in extra zinc, iron, and B12. (3) In addition to meat, poultry, and fish, these nutrients are found in dairy and plant-based foods.

  • Get extra iron from dark green, leafy vegetables, dried fruits, nuts, seeds, molasses, and whole grains. Eating plant-based food along with those rich in vitamin C helps with iron absorption.

  • Zinc is found in whole grains, fortified cereals, legumes, and nuts.

  • Vitamin B12 is very difficult to get without eating any animal products. Vegetarians can eat more dairy and eggs, but vegan women may need to take a supplement or look for fortified foods.

Vegetarians and vegans may want to talk to their doctors or a registered dietician to plan a nutrient-packed diet for pregnancy.

Women need twice as much iron during pregnancy. Aim for 27 milligrams per day. (2)

Learn more: Tips for Creating a Safe Prenatal Yoga Program

Don't Forget about Folate

Folate, also known as folic acid and vitamin B9, is an essential nutrient for preventing birth defects. In particular, adequate folate helps to prevent neural tube defects, those that affect the spinal cord and brain.

The role folate takes in preventing these defects is most critical during the first weeks of pregnancy, which is why all women who may become pregnant should be aware of folate intake. In fact, many doctors recommend that all women of childbearing age include a 400-microgram folic acid supplement in their daily diets. (2)

Your pregnant clients can get more folic acid from foods, including fortified breads, cereals, pastas, and rice, leafy green vegetables, and legumes.

Doctors recommend that women take a 600-microgram folic acid supplement throughout pregnancy. (2)

Do Plan to up Protein

Protein is essential for the development of the fetus, and just over two pounds of protein will be taken in by the baby throughout pregnancy. Your pregnant clients need to up their protein intake by consuming more calories from a variety of healthful, whole foods or by adding in protein supplements like protein shakes or powders.

Women should eat 25 grams of additional protein each day during the second and third trimesters of pregnancy.

Do Find the Right Sources for Omega-3s

Your healthy and fit clients are probably already aware of the importance of consuming adequate amounts of omega-3 fatty acids. These fats are involved in the development of the fetal brain but also decrease the risk of post-partum depression.

What your clients may not know is that they may need to change their current sources of omega-3s. Pregnant women are supposed to avoid consuming too much fish because of the risk of pollutants like mercury.

Fish that are lower in mercury and high in omega-3s include: (4)

  • Salmon

  • Anchovies

  • Herring

  • Trout

  • Sardines

Alternatives to fish include ground flax seeds, walnuts, hemp seeds, seaweed, leafy green vegetable, algae, and canola oil.

Women should limit the above fish rich in omega-3 fatty acids to six ounces or less per week.

Do Avoid These Food and Drinks

In addition to all the nutrients your pregnant clients need to consume more of, there are plenty of things they need to limit or avoid entirely. These include some obvious ones like tobacco and alcohol, but there are other items your clients may be surprised to find they shouldn't eat or drink:

  • Cured meats and deli meats

  • More than 300 milligrams of caffeine per day

  • Artificial sweeteners

  • Raw eggs

  • Raw seafood

Some types of fish are also completely off-limits during pregnancy: swordfish, king mackerel, tilefish, and shark.

Don't Use Cravings as an Excuse to Eat Junk

Pregnancy can lead to a number of cravings, which sometimes indicate that a woman is deficient in a particular nutrient. In this sense, cravings can be useful, but what your clients need to avoid is using cravings as an excuse to consume empty calories.

This is a critical period of time for the health of the developing fetus and the mother. For optimal health for both it is essential that the mom is very intentional about what she eats and that most of the food she consumes is nutrient dense. There is little room for junk food when you're growing a baby.

As a personal trainer you always have the best interests of your clients in mind, but with special clients like those who are pregnant you sometimes need to go the extra mile. Knowing more about nutrition can help you help her make the right choices for her health and that of her new baby.

To learn more about general nutrition and specialized diets, check out the ISSA's comprehensive course on Nutrition.

Share these do's and don'ts of pregnancy nutrition with your clients by clicking HERE.

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ISSA | Nutritionist

By becoming an ISSA Nutritionist, you'll learn the foundations of how food fuels the body, plus step by step methods for implementing a healthy eating plan into clients' lifestyles.


  1. Mayo Foundation for Medical Education and Research. (2022, February 9). Pregnancy weight gain: What's healthy? Mayo Clinic. Retrieved February 1, 2023, from https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy-weight-gain/art-20044360

  2. Vitamins and other nutrients during pregnancy. March of Dimes. (n.d.). Retrieved February 1, 2023, from https://www.marchofdimes.org/pregnancy/vitamins-and-other-nutrients-during-pregnancy.aspx

  3. Staying healthy on a vegetarian diet during pregnancy. (2008). Journal of Midwifery and Women's Health, 53(1), 91–92. https://doi.org/10.1016/j.jmwh.2007.10.009

  4. Mayo Foundation for Medical Education and Research. (2021, December 8). Pregnancy and fish: What's safe to eat? Mayo Clinic. Retrieved February 1, 2023, from https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy-and-fish/art-20044185?p=1

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