Pregnancy Diet for the Third Trimester: Best 3rd Trimester Foods
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The third trimester of pregnancy is a time of rapid growth and development for your baby, making proper prenatal nutrition more important than ever. As your baby prepares for life outside the womb, their brain, bones, and organs undergo critical development, requiring a steady supply of essential nutrients.
For expectant mothers, maintaining a well-balanced diet rich in vitamins, minerals, and healthy fats is key to supporting your baby’s health while also keeping your energy levels up and managing common third-trimester discomforts. Even if you had difficulty eating a balanced diet earlier in pregnancy due to nausea or food aversions, it is never too late to start healthier eating during pregnancy.
In this post, we’ll explore the best foods to eat during the final weeks of pregnancy, discuss key nutrients needed, and provide tips for creating a healthy, balanced diet in the third trimester to fuel your body and your baby’s needs.
Essential Nutrients for the Third Trimester
Maternal nutrition during pregnancy is particularly important in the third trimester because this is a critical period of rapid growth and development for the baby. I’ve listed below some of the key nutrients to support both mom and baby in the third trimester:
Protein: Protein is critical for the rapid growth of your baby and the development of tissues, muscles, and organs. The recommended amount of protein per day during pregnancy is 1.1 grams per kg of body weight at a minimum or about 75-100 grams per day. Try to Include high-protein foods such as lean meats, fish, eggs, dairy products, legumes, nuts, and seeds in your diet in the third trimester of pregnancy.
Vitamin D: Vital for calcium absorption and helps form strong bones and teeth, immune health, helps promote better eyesight, and is an excellent vitamin for healthy skin. While the recommendation for pregnancy is only 400-600 IU per day, recent studies have shown it is safe and more effective for mom and baby to take 4,000 IU per day. Check your prenatal vitamin and talk to your health professional to be sure you are getting enough!
** TOP TIP: While vitamin D can be created in the body when the skin comes in contact with the sun, too much sun exposure is not safe for the skin. Small amounts of vitamin D are found naturally in certain foods, including salmon, sardines, egg yolk, and some mushrooms, and other foods that are fortified with Vitamin D, like dairy products. Still, most people will likely need a vitamin D supplement to meet their vitamin D needs.
Choline and Vitamin B12: Both are critical for your baby’s brain development. Studies show that deficiencies in these nutrients can impact memory, learning, and overall brain function later in life. The primary dietary sources of choline are animal-based products such as meat, poultry, fish, dairy products, and eggs (especially the yolk), as well as cruciferous vegetables, like broccoli and kale, and certain beans, like kidney beans and soybeans. Vitamin B12 is abundant in meat, dairy, and fortified plant-based products.
Magnesium: Helps with muscle and nerve functions, supports a healthy immune system, and can help with leg cramps that often develop in the 3rd trimester. It also plays a role in regulating blood pressure and preventing complications like preeclampsia. Try to include leafy greens, nuts, seeds, whole grains, and legumes in your diet daily.
Iron: The demand for iron increases in the third trimester to support blood production needed to supply the baby oxygen. Baby will also retain enough iron from stores developed in utero to last until they are about 6 months and ready to start solid foods. Include sources like leafy greens, beef, seafood, poultry, lentils, tofu, beans, legumes, and cashews in your 7th, 8th, and 9th month pregnancy diet.
** TOP TIP: Pair a plant-based source of iron with a food high in Vitamin C (like tomatoes and citrus fruits) for enhanced iron absorption. You can also cook in a cast iron skillet to increase iron intake.
Omega 3 Fatty Acids, especially DHA: A high-fat diet rich in omega-3 fatty acids, especially DHA, supports a baby’s eyes, brain, and nervous system development. They can also help reduce the risk of preterm delivery. DHA transfer from mom to baby is actually highest in the 3rd trimester. DHA is most concentrated in fish and seafood like sardines, salmon, tuna, shellfish, and some algae, which most pregnant women do not eat enough of. Aim for about 500mg of DHA daily with combined dietary sources, prenatal vitamins, and/or a supplement.
Calcium: Your baby’s bones and teeth will draw on your calcium stores. Calcium also helps support muscle and nerve function and enzyme and hormone activity, and it plays a role in regulating body fluids. Do your best to consume plenty of calcium-rich foods like dairy foods, calcium-set tofu, cannellini beans, canned and fresh salmon and sardines, calcium-fortified orange juice, and almonds in your 9th, 8th, and 7th month pregnancy diet.
Fiber and Hydration: To combat common third-trimester discomforts like constipation, include fiber-rich foods such as whole grains, fruits, and vegetables. Stay well-hydrated by drinking plenty of water throughout the day with a goal of about 64-96 ounces of water per day.
** Pregnant women have increased fluid needs and therefore, a higher need for electrolytes (sodium, potassium, chloride, calcium, and magnesium). In general, it is best not to restrict salt intake during pregnancy, but consult with your healthcare provider about this, particularly if you have other medical conditions and/or high blood pressure.
Healthy Eating Plan for the Third Trimester
As a registered dietitian, I can promise you that there is no one perfect way to eat a healthy diet in the third trimester. You have options! I do not recommend any weight management diets or fasting plans to lose weight (unless recommended by your healthcare provider for a specific reason), as most pregnant women need close to 2,200-2,600 calories per day or about 300 extra calories per day in the second and third trimesters.
It is best to choose meals and snacks with a combo of FAT + FIBER + PROTEIN + CARB to help keep blood sugar balanced and energy levels up. Here are a few of my favorite recipes to give you some ideas that will support a balanced meal plan for the third trimester:
Breakfast:
Scrambled eggs with spinach, sausage, and whole-grain toast
A few of these tasty Breastfast Egg Muffins or a slice of Spinach and Cheese Frittata
My favorite—Banana Protein Pancakes!
Snack:
Plain unsweetened Greek yogurt with a handful of walnuts or granola topped with sliced strawberries
A scoop of chocolate protein powder* added to this nutrient-dense Chocolate Cherry Smoothie, or a scoop of vanilla protein powder* to this fiber-rich Melon Peach Creamsicle Smoothie
Lunch:
Grilled chicken salad with mixed greens, avocado, and an olive oil-based dressing
Warm, spiced Winter Vegan Soup
Snack:
A banana and a small handful of almonds or almond butter
A delicious Pumpkin Spice Cookie
Dinner:
Baked salmon with roasted sweet potatoes or quinoa and broccoli
An easy twist on a classic quesadilla, Mexican Tortilla Casserole, with added ground turkey or beef for extra protein
Dessert:
A small bowl of mixed berries with a dollop of whipped cream
The Role of Prenatal Vitamins
A healthy eating plan may not always provide all the nutrients you need, especially in the third trimester. Prenatal vitamins help fill nutritional gaps, ensuring adequate intake of vital nutrients such as vitamin D, choline, iron, and DHA. These nutrients work together to support overall maternal and fetal health.
Opt for prenatal vitamins from reputable brands that adhere to strict quality control standards and always look for products that are third-party tested. Choose supplements with certifications such as Good Manufacturing Practices (GMP) to ensure the product's safety, efficacy, and accurate labeling. I also recommend choosing products that are free of artificial colorants.
If you need help choosing a prenatal vitamin, speak to your dietitian or healthcare provider to find the best option for you. I’ve listed a few of my favorite prenatal vitamins here*.
Tips for Healthy Pregnancy Eating Habits in the 3rd Trimester
As a registered dietitian and mom of three girls, here are a few of my top tips for a healthy prenatal diet and lifestyle:
Eat smaller, frequent meals and snacks with adequate protein to avoid heartburn and maintain steady energy levels
Avoid high-fat diets that include unhealthy fats, like fried and processed foods; instead, focus on healthy fats like nuts, seeds, avocados, etc.
Stay active with light exercises like walking and yoga to improve digestion and circulation
Maintain adequate daily hydration with water, electrolyte drinks, bone broth, etc; limit caffeine and avoid alcohol entirely
Try to stay positive and prioritize your mental health as best you can! You are growing a tiny human, which takes so much work. Give yourself grace when there are days when your diet feels off track; every day is always a new opportunity to start again
Final Thoughts…
The third trimester is a time to focus on optimizing your nutrition during pregnancy. Your baby will soon arrive! By eating a balanced diet, incorporating essential nutrients, and maintaining healthy eating habits, you can support your baby’s growth and development while preparing your body for delivery and breastfeeding.
If you are looking for more personalized support, I am accepting new clients for virtual one-on-one counseling. Feel free to reach out! You can also check out my blog, which has plenty of wonderful resources for pregnant and new moms.
Thanks for reading!