The Paleo Diet And Pregnancy - The Third Trimester

This articles forms part of a series covering the Paleo diet and lifestyle to support reproduction from fertility to conception, pregnancy and nursing.

PART 5 - Third Trimester Pregnancy Gripes

During the third trimester, week 28 – week 40 of pregnancy, the physical demands on the mother’s body reach their peak. The baby starts to receive signals from all five senses. The brain develops more than in any other trimester. The soft cartilage throughout the body is transformed into bones that make up the skeletal structure. Skin, hair and nails begin to develop. Around week 34 the baby starts to turn southward in preparation for delivery and in the final weeks of pregnancy, the meconium (an infant’s first bowel movements) build up in the intestines.

During this time many women begin to experience some undesirable physical symptoms. As a result of this increased energy demand, expecting moms may lose some of that energy they regained in the second trimester. Backaches, fatigue and stretch marks may occur as both baby and mom’s body grow bigger. As the baby grows it starts displacing organs including the stomach resulting in some eating and digestive challenges. Hormonal changes and the body’s insulin response are shifting.  Maintaining a Paleo diet and ensuring both mom and baby are receiving nutrient dense, whole foods will play a large part in helping to alleviate many of mom’s symptoms while setting both mom and baby up for helth and strength both through birth and beyond.

Third Trimester Gripes

Smaller Stomach

Your growing baby is displacing much of your stomach and eating large meals is becoming more of a challenge. This is the time to be extra observant of the quality of the food you eat. Often, the idea of grazing or eating multiple mini-meals may appear to conflict with much of the Paleo lifestyle advice, but it is important to remember that, pregnancy is different. Intermittent fasting with infrequent large meals has no place in a healthy pregnancy. You should aim for 4-6 (or more, depending on your needs) small meals spread through the day and night. Having meals and snacks ready to go will reduce preparation time when you need food NOW. Having some pre-cooked bacon or a few of Pete’s Paleo meals will offer a variety of well sourced, nutrient dense options ready when you are.

Sleep Disruptions

Many women experience waking up multiple times throughout the night. This could be a result of having to empty a constricted, displaced bladder more often or the body slowly beginning to establish a rhythm where it needs to wake to be feeding a baby every 3-4 hours. Often women experience hunger when they wake up. Eat.  Subtle shifts in blood sugar can actually wake you up out of a deep sleep. Include some nutrient dense Paleo carbohydrates in your snack to help boost serotonin levels and support returning to sleep. Sweet potato, warm apple with cinnamon, mashed pumpkin, chia pudding or sliced avocado are all good choices that can help aid your sleep.


This is a common problem, with around 40% of women experiencing constipation at some point during their pregnancy. Pregnancy related constipation is not due to a lack of fiber and occurs as a result of the increase in progesterone production. Progesterone acts as a smooth muscle relaxant which is helpful during pregnancy as your baby is growing.

Unfortunately, with your smooth muscles more relaxed and contractions more difficult, peristalsis (the movements along your digestive tract designed to move stool and waste products through) is affected.

Increasing fiber intake with bulk causing substances, such as, flax seeds or psyillium may actually make the problem worse. Instead, focus on

  • Food quality with a clean Paleo diet, free of refined and processed foods
  • Keeping hydrated with lots of water to keep stools soft
  • Warm drinks can help kick start a sluggish bowel. Try some mineral rich bone broth sipped slowly.
  • Magnesium or Vitamin C supplements aid in drawing extra water into your bowels and stimulate peristalsis.
  • Gentle exercise including yoga, walking and even hiking can stimulate peristalsis
  • Consider raising the feet or using a squatty potty to optimize the anto-rectal angle.
  • Including a high quality probiotics along with some naturally fermented foods like sauerkraut, kimchi and grass-fed yogurt (if tolerated) into your diet can support elimination.
  • Iron supplements can be terribly constipating. If you are following a healthy paleo diet full of iron rich foods such as liver, your iron supplement may not be necessary. Please discuss this with your practitioner before changing your regime.


Hemorrhoids are common during pregnancy, particularly in the third trimester. Some women get them for the first time while they are pregnant. If you have had them before pregnancy, you are quite likely to have them again now. They may also develop while you are pushing during the second stage of labor and are a common early postpartum complaint. In most cases, hemorrhoids that developed during pregnancy will begin to resolve soon after you give birth, especially if you have been careful to avoid or reduce constipation.


Heartburn is another common discomfort is also caused by an increase in progesterone. This time progesterone’s muscle relaxing effects can influence your esophageal sphincter, the muscle at the top of your stomach that holds your stomach acid in place. When this muscle relaxes, the acid that is naturally present in your stomach may be forced up and into your esophagus, causing painful heartburn.

It is vital to understand that this heartburn is not due to an over-production of stomach acid; rather, the stomach acid produced is not where it is supposed to be. Most women seem to complain of heartburn during the third trimester as the growing baby is displacing your stomach upwards and literally squeezing acid up and creating this discomfort.

Reducing your stomach acid with the use of antacids and the like will only do you a digestive disservice by causing sub-optimal digestion and reduced nutrient assimilation. Instead, a few lifestyle modifications may be extremely helpful:

  • Eat smaller meals focusing (yet again) on nutrient and calorie density.
  • Eat slowly and chew your food well.
  • Avoid drinking while eating. Excess liquid just takes up space. Sip water, herbal teas between meals. Peppermint or ginger teas are ideal and will help to soothe your digestive system.
  • Stay upright after meals.
  • Sleep with your torso elevated by a tower of pillows.
  • Wear loose fitting clothing.
  • Keep a food journal. If you notice that certain foods are causing your heartburn to flare up, simply avoid them.

Increased Insulin Resistance

Even if you are not struggling with or have not been diagnosed with diabetes or gestational diabetes it is important to understand that your body is becoming increasingly insulin resistant, especially in the third trimester, and diet needs to be modified accordingly.

Insulin allows sugar (glucose) enter cells, where it is used for energy. Insulin is a storage hormone which helps muscles, fat, and liver cells store sugar to be released when it is needed. If the body tissues do not respond properly to insulin (known as insulin resistance), the blood sugar level rises. 

In pregnancy, insulin resistance is a normal physiologic adaptation.  This storage hormone facilitates rapid fat accumulation, brain development and overall growth in of the baby in the third trimester. This rapid growth is essential to ensure your baby's survival outside the womb. Unfortunately, eating a standard American diet or even a Paleo diet that is too focused on dense carbohydrate sources often results in gestational diabetic mothers, large for gestational age infants (babies who are larger than expected) and excessive pregnancy weight gain, all of which are risk factors for a variety of obstetrical complications.

If you have suffered from PCOS before pregnancy, insulin resistance is even more of a concern. Pre-pregnancy obesity or PCOS can put you at risk for developing later onset gestational diabetes and exaggerate the normal physiologic insulin adaptations in late pregnancy.  

To support both your body and the optimal growth and development of your baby in this critical stage, be sure to:

  • Eat and enjoy proteins and healthy fats till you're satiated. Grass-fed meat, free range poultry, wild caught fish, avocados, eggs, olive oil, coconut oil, ghee, grass-fed butter, full fat yogurt (if tolerated) are all smart choices. Using Pete’s Paleo meals, bacon and bone broth provides nutrient dense, Paleo compliant options that require little to no preparation.
  • Load up on dark, leafy green vegetables including kale, chard, collards
  • Starches and carbohydrates are still necessary but should be enjoyed moderately (up to about 150 a day). Sweet potato, winter squash, yam, turnip, parsnip, pumpkin are all nutrient dense, fiber-rich options which will also support healthy gut flora and bowel movements.
  • Include probiotic foods for optimal digestion, immune system function and vaginal flora (your baby will soon be passing right by this region). Raw unpasteurized sauerkraut, fermented vegetables, kombucha and probiotic supplements are all good options.  
  • Do you best to avoid or really limit sugars and fruits including honey, maple syrup and date sweetened paleo treats. Stick with low sugar fruits like berries, grapefruit, green apples, and small paleo treats enjoyed after some movement or walking.

A few further suggestions to get you through your third trimester:

  • Be mindful of your sodium intake as you are more prone to swelling in the third trimester.  
  • If your sleep is disturbed and you feel tired, sleep, nap and/or rest whenever you feel it is necessary. Exhaustion and sleep deprivation further contribute to insulin resistance and glucose response in your body.  
  • Move your body. Walk and do yoga. Both of these activities are shown to reduce insulin resistance, support peristalsis and bowel movement and calm both body and mind.
  • Workout if it is part of your routine. Ensure your workouts are scaled and appropriate for the changes that are happening in your body during the third trimester.

Following a Paleo diet and lifestyle during your pregnancy can play an important role in ensuring you are getting a full spectrum of nutrients, vitamins and minerals for both you and your growing baby. The Paleo approach of emphasizing food quality and sourcing will support the demands of an expectant mom and a healthy, developing baby.

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