Nutrition During Pregnancy: what to eat and what to avoid

In honour of Mother’s Day approaching and all of our #TeamMTMM new mom’s and moms-to-be, this week’s #MastersMonday is focused on nutrition during pregnancy. 

During pregnancy the body requires an increased nutrient supply to meet both mom and babe’s needs. It’s well understood that a diet lacking in key vitamins and minerals can negatively affect a baby’s development, but new research is demonstrating that the maternal diet  - both prior to and during pregnancy  - can also have massive effects on a child’s risk of chronic diseases!

Choosing healthy, nutrient dense foods will help ensure not only a healthy pregnancy, but will also make it a lot easier to return back to your normal bodyweight and function after giving birth.


Obviously, women are expected to gain some amount of weight during the course of their pregnancy, but how much is normal and where does all the weight come from?

The goal is to gain 25-35lbs (11-16kg) over the course of a pregnancy for a woman who is normal weight going in.  Ideally this would look like 3-5lbs (1.5-2.25kg) in the first trimester, followed by a gradual and consistent gain thereafter.

Where does the weight go? 

If your baby weighs only a few kilos when born it can leave you wondering where all those other kilos go. Here are some average figures:

Baby: 6.5-8 lbs / 3.0 to 3.6kg
Placenta: 1.5 lbs / 0.7kg
Amniotic fluid: 2.2 lbs / 1kg
Larger uterus: 2.2 lbs / 1kg
Increased blood volume: 3 – 4 lbs / 1.4 to 1.8kg
Extra fluid: 3-4 lbs / 1.4 to 1.8kg
Breast tissue: 2.2 lbs / 1kg
Fat stores: 6-8 lbs / 2.7 to 3.6kg




When pregnant, increased progesterone levels decrease a woman’s ability to fight infection and make them more susceptible to the effects of food borne infections. Certain foods carry an increased risk and medications and interventions to treat such infections in pregnant women are limited, therefore it is important to reduce the risk of consuming dangerous bacteria by avoiding the following foods:

Raw or smoked fish, oysters
Raw or undercooked meat & eggs
Deli meats & salads, cured meats
Unpasteurized soft cheeses or dairy


Additionally, there are some foods which are important to limit for a variety of reasons:

Soy and soy products : these act as phytoestrogens and can alter your body’s hormonal profile. Keeping intake to a minimum is recommended.

 Alcohol: the FDA has recently stated that the risk of alcohol consumption in moderation during pregnancy was previously over-emphasized. While high intakes of alcohol during pregnancy can cause fetal alcohol spectrum disorders, small amounts of alcohol later in pregnancy are unlikely to negatively impacts. Despite this there is no agreed upon “safe” amount of alcohol and therefore the recommendations remain for women to abstain.

Canned tuna: can contain high amounts of mercury, therefore intake should be limited (but a can every once in a while is fine!)

Caffeine: Again, the risk of consuming caffeine during pregnancy was previously overstated. Consumption of up to four cups of coffee a day is not related to any negative developmental outcomes or increased risk to the pregnancy. While some caffeine is not harmful, keep your intake to 115-175mg daily for both mom and babe. (an average 12 oz drip coffee is about 80mg)

Vitamin A: While eating foods with vitamin A is not harmful, avoid any additional supplements or topical creams (i.e. retinol) as it can quickly reach toxic levels and cause retinoic acid syndrome.



Iron rich foods


During pregnancy, a women’s blood volume is increasing, particularly during the third trimester, and the need for iron increases.  Foods rich in Iron such as broccoli, leafy greens, legumes, dates and meat should be consumed liberally. Iron supplementation should occur only under physician and NP guidance as there is no benefit to women who have adequate stores and high doses can cause unnecessary inflammation, gastrointestinal distress and plasma volume expansion.

Eating foods that are rich in Vitamin C assists with the absorption of iron from meals. Oranges, berries and bell peppers are great sources of Vitamin C.

Folate rich foods

Folate is very important for the health of both mother and babe, especially during the first trimester, and are key to normal neural tube development. Foods rich in folate include fortified grains, dark leafy greens, legumes, avocados and cereal, although a folic acid supplement is generally recommended as well. This is important to have on board prior to conceiving if possible as the critical period for folate encompasses the first four weeks of pregnancy (before you are even aware of the exciting events occurring).  


Iodine is essential for healthy brain development in the fetus and young child. In addition, it is key to thyroid health and TSH production. A women’s iodine requirements increase significantly during pregnancy to ensure adequate supply. The best source of iodine is in iodized table salt, something which is dropping with the increasing consumption of Himalayan pink salt (which has other great benefits but does not contain iodine). Don't be afraid of increasing your consumption of iodized salt, but there’s no need to go too nuts.


North American's have been found to have very low fish consumption, and a need for increased omega-3 intake. This is particularly true for pregnant women, whose developing fetus can benefit in terms of neurological and visual development. 

The FDA revised their guidelines in 2014 recommending pregnant women consume two 6oz servings of oily fish per week to boost their omega-3 intake. It is agreed that this amount will provide both mother and babe with the benefits of omega-3 intake but will avert the risks associated with high levels of mercury or pollutants. ‘Oily fish’ includes mackerel, salmon, trout, anchovies, sardines, herring, whitebait, fresh tuna, and to a lesser degree, cod and haddock.

For mothers who are unable or unwilling to eat fish, a supplement of 450mg EPA/DHA daily is considered equivalent to 2 servings of fish a week, however it is important to note the source of the EPA/DHA. Fatty acids obtained from the body of a fish are generally considered safe, whereas fatty acids from the liver of a fish (i.e. cod liver oil) are best avoided. This is because omegas sourced from fish liver are quite high in retinol (Vitamin A), which can have harmful effects on the fetus.

Supplements from algae are also an option, although omega-3 from whole foods have been shown to have greater benefit than those from supplements alone.


It’s easy to get caught up in all the ‘rules’ surrounding eating for pregnancy, and even harder to weed through what constitutes science-based recommendations versus old-wives-tales or internet fake news. This is especially true because guidelines continue to change with emerging research. If you’re feeling bogged down or overwhelmed by it all, fear not! Reach out to one of our coaches and we’d be happy to develop a personalized plan to keep you feeling great, performing well, and ultimately giving your baby the best chance at a healthy start.