Pregnancy Nutrition – The Second Trimester

Right now I’m in the final week of the second trimester (time flies when you’re gestating, ammiright?!), so I thought I had better get my butt in gear and talk about second trimester pregnancy nutrition!

First up, a little disclaimer: I am in no way an expert on pregnancy, nor am I a physician or a clinical dietitian. So the information I’m sharing on pregnancy nutrition comes from a combination of information I’ve gleaned over the course of two degrees in nutrition (BSc and MSc), further reading, and my experiences with my own pregnancies. Please be sure to speak to your health care professional if you have any specific concerns.

A pregnancy ultrasound photo on a grey background with a green smoothie to the side

Back in the first trimester, we talked about how it’s really just survival mode – you do what you gotta do to get through it, even if that means eating boxed macaroni and cheese on repeat. (I know I’m not alone here.)

In the second trimester, however, the vast majority of us are feeling pretty good. Hopefully the nausea has settled down, the food aversions are passing, and your energy is coming back. In approximately 60% of women, the nausea subsides by the end of the first trimester (12-13 weeks), and only 9% of women experience it beyond 20 weeks. If you’re one of the unlucky few who experiences nausea beyond that point: I’m very sorry.

For the rest of you, it’s time to start paying attention to nutrition!

How much do I need to eat in the second trimester?

While you may be eating for two, it’s important to remember that one of you is the size of an orange. Or a heirloom tomato. Or whatever fruit or vegetable your pregnancy app is comparing your baby to at the moment.

Some resources suggest that pregnant women need up to 300 extra calories in the second trimester. While you do definitely need some extra energy in the second trimester, your body doesn’t actually need that much more food to grow a healthy baby. It’s best to think about quality over quantity.

Depending on your genetics and activity level, you may need as little as 100 extra calories per day. Even 300 extra calories isn’t exactly an extra meal, it’s more like a couple of extra snacks.

What DOES increase in the second trimester is your need for certain nutrients, including iron, vitamin B12, choline, iodine, vitamin A, and folate, as well as macronutrients like protein and healthy fats.

How much protein should I eat during pregnancy?

When it comes to pregnancy, recent research is suggesting that the protein requirements have been drastically underestimated. Because, get this: the current recommendations for protein requirements in pregnant women are based on studies of non-pregnant people.

So what’s been done up until now is studies on non-pregnant people, including men, and then a good old educated guess to bump up the protein requirement for pregnancy.

Here’s the good news, A 2015 study – the first EVER study to directly estimate protein needs in pregnant women – showed that actual protein needs were 39% higher in early pregnancy (before 20 weeks) and a whopping 73% higher in late pregnancy (after 31 weeks) when compared to the current daily recommendation of 0.8 grams per kilogram of body weight.

That means that in early pregnancy the protein requirement would be closer to 1.22 grams and in late pregnancy, more like 1.52 grams of protein per kilogram of body weight. We can aim for a general goal of about 80 grams of protein per day in the first half of pregnancy, and about 100 grams of protein per day in the second half. If you’re very physically active, you may even need a bit more than that.

Good sources of protein include:

  • Eggs
  • Cheese
  • Yoghurt
  • Nuts and nut butters
  • Beans and legumes
  • Lentils

Of course if you’re not vegetarian you can also include meat, poultry, fish, and collagen protein in this list.

What about fat?

I can’t stress this next point enough: you need fat in your diet to grow a healthy baby. 

Why? First of all, your body’s need for fat-soluble vitamins A, D, E, and K go up during pregnancy, and without adequate fat in our diets we can’t properly absorb them.

Also consider the fact that your baby’s brain, which is being created from scratch, is comprised of approximately 60% fat. And not only is the brain made from mostly fat, but in order to create a healthy brain the demands for nutrients such as choline and omega-3 fats, particularly DHA, are high.

Even cholesterol plays an important role in hormone synthesis, which is critical for your baby’s development.

DHA and choline are both found in abundance in fatty foods, such as egg yolks. If you were to ditch the yolks you’d get adequate protein, but would miss out on these important nutrients.

Full-fat dairy products have also proven to be beneficial in pregnancy, providing fat soluble vitamins alongside the fat required to absorb them. Mother nature is pretty smart, as it turns out, so eating foods in their most whole and real form is a good move during pregnancy.

Another benefit of eating fat during pregnancy is that it helps to keep your blood sugar stable, and you need to eat less of it to fill up. As your baby starts to crowd out your stomach space you may find that you feel better eating smaller yet richer meals.

Good sources of healthy fats include:

  • Full-fat yoghurt
  • Cheese
  • Butter
  • Olives
  • Coconut
  • Avocado
  • Nuts
  • Seeds

What are my iron needs during pregnancy?

In both of my pregnancies my iron has been great going in, and stayed perfectly fine until around week 25 when the baby starts poaching it from me. Everyone is different, though, so it’s really important to have your iron stores tested in early pregnancy, and then have your hemoglobin tested at regular intervals from mid pregnancy.

Women of childbearing age need 18mg of iron per day, and during pregnancy that amount gets bumped up to 27mg per day, which may or may not be enough.

Vegetarians need to be particularly mindful of iron levels, as non-heme (plant-based) iron is not absorbed by our bodies nearly as well as heme (animal) iron. Inadequate iron intake during pregnancy is a risk factor for a number of complications, including preeclampsia, hypothyroidism, and pre-term birth. Low maternal iron may also result in impaired fetal brain development and stunted growth.

Good sources of iron include:

  • lentils
  • beans
  • dark leafy greens such as spinach, kale, and bok choy
  • spirulina
  • soy products such as tempeh and tofu
  • blackstrap molasses
  • pumpkin seeds
  • broccoli
  • wheat germ

Dried fruits can also be a good source as they are often dried in iron pans, and cooking acidic foods such as tomatoes in cast-iron cookware increases iron content of the food.

Some women go all the way through pregnancy without needing supplemental iron, and others end up needing quite a lot. My iron-sucking offspring seem to want more than the recommended 27mg, so I’m currently taking a daily prenatal supplement with 45mg of iron, AND 100mg of iron every other day.

For a while I was taking daily spirulina instead of an iron supplement, and that was also working quite well. I want to dig into that topic separately as there are some safety concerns regarding spirulina that you should be aware of should you choose to go that route, but I will say that it has been shown to be very effective in treating iron deficiency and safe in pregnant women at doses up to 1500mg per day.

Is vitamin B12 important during pregnancy?

Yep, critically.

Vitamin B12 is extremely important during both pregnancy and breastfeeding, and it’s a very important vitamin for vegetarians to be aware of. Without adequate amounts, risk of neural tube defects and pre-term delivery increase. Babies born to mothers who are vegetarian and are exclusively breastfeeding may not get enough B12 if their mother is not supplementing.

Accordingly, the American Dietetic Association recommends B12 supplementation for both vegans and lacto-ovo vegetarians during pregnancy and lactation to ensure enough B12 is transferred to the fetus and infant, as undetected and untreated B12 deficiency in infants can result in severe and permanent neurological damage.

The US recommended daily average (RDA) of vitamin B12 for adults is 2.4 µg (micrograms). This bumps up to 2.6 µg during pregnancy, and 2.8 during lactation and breastfeeding. Some European countries recommend 3.0 µg/ day.

Vitamin B12 is found in most animal foods, including meat, fish, poultry, eggs, and milk products. Other than some fermented foods, there are very few non-animal food sources of biologically active B12. If you’re vegetarian, and especially if you’re vegan, you’ll either want to ensure your pregnancy multivitamin has adequate bioavailable B12, or take a dedicated B12 supplement.

Recommended resources

This post really just scratches the surface when it comes to pregnancy nutrition in the second trimester. If you’re interested in learning more, I recommend you check out these sources:


Food Heaven Podcast interview with Lily Nichols, RD, author of Real Food for Pregnancy.


Real Food for Pregnancy (<– affiliate link!)
Pregnancy Nutrition – The First Trimester
Vegetarian Pregnancy Superfoods – Eggs
What you should know about iron
What you should know about B12





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