Optimal Protein in Pregnancy

Written by: Ryah Nabielski, MS, RDN

Eating enough protein during pregnancy is critical for a healthy baby. Protein requirements increase throughout pregnancy to support growth and development. But eating protein can be challenging because of food aversions, morning sickness, cravings, and other factors. 

As if eating protein wasn’t difficult enough, new research proposes pregnant people may need even more daily protein than outdated nutrient recommendations suggest. Today’s article will dive into the latest research and offer practical solutions for meeting your protein needs during pregnancy. 

Keep reading to learn more about: 

• Why protein is essential during pregnancy
• Determining your optimal protein intake 
• Food aversions and morning sickness
• The best protein choices during pregnancy
• Protein tips for pregnancy, including using protein powders

Let’s get started! 

The Importance of Protein in Pregnancy 
Amino acids make up dietary protein, and we use those amino acids as building blocks for the over 17,000 human proteins. Some amino acids are essential, meaning we need to get them from the diet, while others are non-essential, and the body can make them. During pregnancy, some non-essential amino acids become conditionally essential, meaning we need more in the diet.
The mother’s diet is the only source of protein for the developing fetus. She needs to eat enough to support the rapid rate of growth and development, promoting healthy pregnancy outcomes. Protein builds body structure, enzymes, hormones, neurotransmitters, immune proteins, and transport proteins like hemoglobin that carries oxygen in the blood.
The impact of nutrition on pregnancy doesn’t stop with birth; it impacts the mother’s health through postpartum and breastfeeding and the infant’s through childhood and adulthood. 

Optimal Protein Intake for Pregnancy 
The Recommended Dietary Allowance (RDA) for pregnancy is 0.8 grams of protein per kilogram of body weight per day in the first trimester. In the second trimester, the RDA is 1.1 grams of protein per kilogram of body weight per day. These values are equivalent to 0.36 and 1.1 grams of protein per pound of body weight per day, respectively. 
The RDA is the minimal requirement but doesn’t represent optimal intake. 
More recent research suggests the RDA underestimates protein requirements during pregnancy; actual requirements are higher, with protein needs increasing throughout gestation. 
Actual protein needs may be closer to 1.2 grams per kilogram by around 16 weeks of pregnancy, increasing to 1.52 grams per kilogram by week 36 in later pregnancy. For reference, 37 weeks is considered full-term, but most deliveries occur around week 40. 
A woman who weighs 150 pounds before pregnancy may need to eat over 100 grams of protein per day as her pregnancy progresses! 

Additionally, a higher overall protein intake helps her to get enough of the essential amino acids: histidine, isoleucine, leucine, lysine, methionine, tryptophan, phenylalanine, threonine, and valine. 

Requirements for conditionally essential amino acids, including glycine, glutamine, and arginine, are also easier to meet with a higher overall protein intake from various protein sources. 

Food Aversions, Morning Sickness, and Cravings
Over 60% of women report experiencing some food aversions during pregnancy, and over 80% report nausea. Food aversion and nausea often go together, along with changes in taste perception and sensitivity to smell. 
Morning sickness and food aversions are most likely to occur in the first trimester between weeks 6 and 12 of pregnancy. For some women, nausea and aversions continue into the second trimester or can last the entire pregnancy. Hyperemesis gravidarum is an extreme morning sickness with excessive nausea and vomiting, often lasting throughout pregnancy. Symptoms resolve after delivery. 
Unfortunately, women may have aversions to protein foods like meat, eggs, and fish. Some hypothesize these aversions are evolutionarily protective and help limit exposure to unsafe food during pregnancy when immunity is low. 
Other evidence suggests symptoms are related to hormonal changes in pregnancy, such as the rise of progesterone and human growth hormone, which affect digestion and food preferences. 
Despite the increased need for protein during pregnancy, you may crave carbohydrates. Cravings may signal missing nutrients in the diet, such as salt or protein, or the need for more calories and energy. 
In many cases, cravings can be helpful messages from the body. Still, on the other hand, cravings that lead to compulsive eating of ultra-processed food can contribute to gestational diabetes or other pregnancy complications. 

Protein Sources – Plant Vs. Animal Protein 
Both plant and animal sources contribute to overall protein intake. Animal sources tend to be more nutrient-dense, better absorbed, and contain all the essential amino acids. Plant foods provide fiber, vitamins, minerals, and phytonutrients for microbiome balance and a healthy pregnancy. 
A recent study examined plant-based vs. animal-based protein intakes during pregnancy, suggesting a positive correlation between animal protein and prenatal growth and birth weight. There wasn’t the same association with plant proteins. 

How to Optimize Protein Intake During Pregnancy 
Eating enough protein during pregnancy can be challenging, but you can meet your needs with a little effort. Here’s how:

• Eat protein with every meal and snack. Include protein, veggies, healthy fats, and unprocessed starches (legumes, starchy veggies, whole grains, or fruit) with meals. Protein helps to balance blood sugar, providing energy stability. Please read this article for an overview of prenatal nutrition. 

• Eat protein even if you don’t feel like it. While some protein foods may be a turnoff, eating protein regularly throughout the day can help lessen nausea and other symptoms of morning sickness. Good hydration will help, too. 

• Include animal protein. If you are able and willing to eat animal proteins, they are highly beneficial during pregnancy. Choose grass-fed beef, pastured chicken and eggs, organic dairy, and wild fish. If aversions are high, mix protein into other food (such as chili), get help with food preparation, and increase plant proteins (like beans, peanut butter, and hemp seeds). 

• Eat a variety of protein sources to supply the essential and conditionally essential amino acids. Get more glycine in the diet by including bone broth, collagen protein, gelatin, and slow-cooked meats. Good sources of arginine include poultry, dairy, and legumes. 

• Manage morning sickness. Get ahead of nausea by keeping some food in your belly all the time. One strategy is to snack on nuts (or another protein food) every 15-30 minutes. Eat in the night when you wake up to help prevent nausea in the morning. 

• Eat fish 2-3 times per week. Fish is a good source of protein and contains beneficial omega-3 fats for brain development. Avoid large predator fish and choose smaller ocean fish like salmon, mackerel, and sardines. If the smell of fish is bothersome, try a cold salmon salad instead of a warm fillet. 

• Use protein powders. Protein powders are an excellent way to increase protein intake during pregnancy and may be well-tolerated if you experience food aversions or morning sickness. Twenty2 Nutrition offers quality grass fed whey protein, collagen-egg protein, and vegan protein powders, all suitable during pregnancy. You can even rotate between the three sources to increase protein variety. 

Now that you know about protein and pregnancy, the most helpful advice is to do your best with nutrition and trust your body. Your pregnancy meals may not match up to the ideal picture you have in your head, and that’s okay. Listen to your body, eat a balanced diet, include various protein sources, and focus on what feels (and tastes) good to you.

References

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942872/ 
2. https://pubmed.ncbi.nlm.nih.gov/32939556/
3. https://pubmed.ncbi.nlm.nih.gov/29909700/ 
4. https://pubmed.ncbi.nlm.nih.gov/11883917/ 
5. https://pubmed.ncbi.nlm.nih.gov/37525006/ 
6. https://pubmed.ncbi.nlm.nih.gov/27180176/ 
7. https://pubmed.ncbi.nlm.nih.gov/37525006/ 
8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9785913/
9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6397768/ 
10. Real Food for Pregnancy: The Science and Wisdom of Optimal Prenatal Nutrition by Lily Nichols 

This article is for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider before changing your diet or beginning a new supplement, especially if you are pregnant or breastfeeding, take medication, or have a medical condition. 

Ryah Nabielski, MS, RDN is a Registered Dietitian, functional nutritionist, writer, and recipe creator. Ryah helps clients use a natural, food-as-medicine approach to improve fertility, pregnancy, hormone balance, autoimmunity, and discover a healthy relationship with food and body. Learn more about Ryah and her private practice at econutrition.co.