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Pregnancy Nutrition 101 – How To Optimize Your Diet

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During pregnancy nutritional intake becomes more important than ever.

The foods you eat are a source of nutrition for both you and your baby. In fact, this is the only period in your life when what you eat directly impacts another human being.

The aim of this article is to highlight key nutritional recommendations and eating habits during pregnancy to help optimize health.

As a note of caution, during pregnancy always consult your physician prior to making any drastic changes to your diet and lifestyle. The following points are only educational recommendations and should not be followed directly without approval from a trained dietician or medical professional.

Pregnancy Based Nutrition – Tailoring Weight Gain

While pregnancy is not the time to lose weight, women should be conscious of the amount of weight they are gaining.

Studies show that not gaining enough weight during pregnancy can result in negative outcomes such as delayed development, preterm birth, increased mortality rates and even behavior problems (Bale, Stoll & Lucas, 2003; Aarnoudse-Moens et al., 2009).

However, research also shows that gaining too much weight or being overweight / obese during pregnancy increases the risk of complications and conditions affecting both mother and child.  These can include increased risk of:

  • Gestational diabetes,
  • Gestational hypertension (high blood pressure),
  • Cesarean delivery,
  • Birth defects and even fetal death (Leddy et al., 2008; Dinatle et al., 2010).

In addition to these shorter term issues, research shows maternal obesity significantly increases the risk of childhood obesity (Rooney & Schauberger, 2012).

Therefore, finding a healthy balance, where there is a natural and small amount of weight gain is optimal for growth and development.

Recommendations for maternal weight gain tend to be based on the weight of the mother pre-pregnancy, with underweight women being encouraged to gain more weight during pregnancy compared to overweight individuals  (Rasmussen & Yaktine, 2010).

The recommendations for weight gain are as follows:

Underweight: 28 to 40 pounds

Normal: 25 to 35 pounds

Overweight: 15 to 25 pounds

Obese: 11 to 20 pounds

For twins, the recommendations are naturally higher:

Normal: 37 to 54 pounds

Overweight: 31 to 50 pounds

Obese: 25 to 42 pounds

Pregnancy Nutrition: Calories 

Pregnancy is a time of anabolism, or growth.

You often hear the saying, “eating for two”. While this is true, you are eating for yourself and the baby, it does not mean you that you should eat twice the amount of food you currently consume. Remember, a newborn baby weighs around 10% of a grown female…

Research shows women should only require approximately an extra 300-500 calories per day during the second and third trimesters (Mahan et al., 2016). More active individuals may need to increase this margin further, to compensate for increased energy expenditure.

One aspect that many people forget is that although they require 300-500 more calories for the baby, they must account for a decrease in activity. In other words, if they quit the gym or shorten their sessions (which they must at some point), they may actually burn 500 calories LESS per day. Therefore, the total energy balance or requirements may not change.

Despite these points, many females will severely overstep the 300-500 calorie mark due to cravings, a sedentary lifestyle (i.e. they take time off work, are less busy, watch more tv, quit the gym etc) and hormonal alterations.

While it’s very easy to make the excuse you are eating for 2, as you can see, the requirements in total daily calories is actually very small. If you are overweight, it’s even more important you don’t make this mistake as further weight gain can cause issues, as discussed above.

Pregnancy Nutrition: Macro & Micronutrient Requirements 

Pregnant women are encouraged to eat a nutrient dense diet containing lean protein, low fat dairy, whole grains, fruits and vegetables, and healthy sources of fats such as olive oil, nuts and avocados.

While some people may be strict low-carb dieters, or follow other dietary trends such as Intermittent fasting or other methods, it may be the time to take a step back and just have a healthy, well-balanced intake. Anything extreme during pregnancy (i.e. severe carb restriction) may not be the best idea, at least until we have more research.

In addition to prioritizing the intake of nutrient rich foods, pregnant women may also wish to supplement some of the key vitamins and minerals, to ensure optimal doses are achieved. This, however, is something you should discuss with your physician prior to commencing any supplementation. Along with a general multivitamin, there are some key nutrients discussed below that have a pinnacle role.

Pregnancy Nutrition: Iron Intake 

The World Health Organization have estimated that 41.8% of pregnant women worldwide are anaemic. Along with the negative side effects for a normal female, iron deficiency or anaemia poses an even larger risk during pregnancy.

Following the birth, research shows between 8-30% of women stay deficient for up to 12 months after the birth, meaning some will likely never recover from the loss of Iron during birth (Bodnar et al., 2002).

For your baby, maternal iron deficiency anaemia increases risk of low birth weight and possibly preterm delivery, mortality and may even impair the mother-infant interaction and immune system (Beard et al., 2005).

Research suggests that supplementation with 27 mg iron daily during pregnancy is recommended, with previously anaemic women needing 60 mg daily until the anaemia is resolved. Again, you must seek medical advice before using these recommendations yourself (Kaiser & Allen, 2008).

Good food sources of Iron include:

  • Squash and Pumpkin Seeds,
  • Liver (Chicken),
  • Seafood such as Oysters, Mussels, Clams etc,
  • All nuts (Almond, Peanut, Cashew etc),
  • Beef and Lamb,
  • Beans and Pulses,
  • Whole Grains, Fortified Cereals, and Bran,
  • Dark Leafy Greens (Spinach, Swiss Chard),
  • Dark Chocolate and Cocoa Powder (YUM!).

Pregnancy Nutrition: Folate Intake 

Folate (Vitamin B9) is essential in the prevention of neural tube defects.

Studies show that neural tube defects severely harm the development of the brain and spinal cord and in some cases can even be fatal for the baby (Lassi et al., 2013; Scholl & Johnson, 2000).

Intake is most critical within the first four weeks of pregnancy when the brain and spinal cord are forming. Many cereal grains are now fortified with folate, while dark leafy greens and legumes are also a good natural source.

However it can be difficult to achieve optimal levels through food alone, so supplementation is commonly recommended to pregnant women (WHO, 2012; US DHHS, 2005).

Pregnancy Nutrition: Calcium Intake 

During pregnancy, there is actually a natural adaptation in the efficiency of calcium absorption, making it more easily absorbed within the body (Ross et al., 2011; Hacker et al. ,2012).

Therefore, only women with suboptimal intakes (<500 mg/day) may require calcium supplementation in order to meet both maternal and fetal bone requirements (Hacker et al., 2012). For most, they should focus on whole food sources high in calcium, this should be sufficient to meet their daily requirements.

Good food sources of Calcium include:

  • Dark Leafy Greens (also great for controlling weight gain),
  • Low Fat Cheese,
  • Low Fat Milk & Yogurt,
  • Chinese Cabbage (Pak Choi, Bok Choy),
  • Green Vegetables (Broccoli, Okra, Green Snap Beans).
  • Almonds,
  • Canned Oily Fish.

Pregnancy Nutrition: Omega 3 Fatty Acid Intake

I’ve discussed the amazing benefits of Omega 3 Fats for everyone over on bodybuilding.com and in other articles.

Maternal nutrition has (unsurprisingly) confirmed the importance of fatty acid consumption as part of an optimal nutrition plan during pregnancy (Ramakrishnan et al., 2010). Research has also shown that the amount of omega-3 fatty acid in the fetus is directly correlated with the amount ingested by the mother, so it is essential that the mother consumes adequate amounts on a daily basis (Dunstan et al., 2008).

Sadly, most women do not reach the recommended minimum, of 300–900 mg of EPA+DHA per day. As stated above, this means the fetus is not receiving adequate amounts of these vital nutrients in the womb (Judge et al., 2000).

But why is this important? Well, omega-3 during pregnancy can have many beneficial effects, including:

▪Proper development of the brain and retina (Ramakrishnan et al., 2010; Dunstan et al., 2008).

▪Reduced risk of pre-term delivery (Olsen et al., 2008; Harper et al., 2010).

▪Aiding labor by reducing inflammation in the uterus (Olsen et al., 2008; Roman et al., 2006).

▪Helping to achieve a normal birth weight (Mackrides et al., 2010).

▪Protection against allergies (Krauss-Etschmann et al., 2008; Furuhjelm et al., 2009).

Other research shows that consuming lots of fish (the most common source of omega 3) has the potential to increase the likelihood of mercury exposure and the consequential greater risk of attention-deficit hyperactivity disorder related behaviors (Carocci et al., 2014).

However, research has shown that limiting consumption to 2 servings per week of low-mercury seafood sources like shrimp, salmon, catfish and sardines poses no risk to the foetus (Mozaffarian & Rimm, 2006; Mahaffey, 2004).

Therefore, it becomes even more important to source high quality fish or omega 3 supplementation during pregnancy. Once you have done this, it may be wise to eat a few servings of seafood and supplement with 1-2 grams of EPA + DHA per day (Greenberg et al., 2008).

Pregnancy Nutrition: Barriers to Healthy Eating

Many women tend to struggle with nausea and vomiting, or the dreaded “morning sickness” at some point early in their pregnancy.

As a result, consuming adequate calories from healthy,  nutrient dense food can sometimes be a struggle.

Some potential strategies to help work around this are (Berardi & Andrews, 2015):

▪Eating more frequent but smaller meals,

▪Avoiding textured and strong smelling foods,

▪Including blander, easier to digest foods when possible,

▪Limiting high fat foods, spicy foods and large meals that may cause digestive issues or sickness,

▪Trying sour/tart liquids in place of water (e.g. lemon water).

Pregnancy Nutrition: Food Safety

As a result of hormonal changes causing reduced immunity, pregnant women and their foetuses are at increased risk of developing foodborne illnesses.

Of greatest concern during pregnancy are strains of Listeria monocytogenes, Toxoplasma gondii, Brucella species, Salmonella species, and Campylobacter jejuni. (Taylor & Galanis, 2010).

Even more than normal, pregnant women should closely adhere to food-safety recommendations outlined in the Dietary Guidelines for Americans (McGuire, 2011).

Pregnancy Nutrition: Things to Avoid 

For the safety of the foetus and for improved outcomes of pregnancy, women should avoid:

Drinking Alcohol:  Alcohol consumption during pregnancy, especially in early pregnancy, may result in behavior and / or neurological defects in the baby and impact a child’s future cognitive (brain) and behavioural function. No safe level of alcohol consumption during pregnancy has been established (McMillen et al., 2008; Berardi & Andrews, 2015).

Drinking Excessive Caffeine: Research on birth defects has indicated that moderate or high amounts of beverages and foods containing caffeine does not increase the risk of congenital malformations, miscarriage, preterm birth or growth retardation. However, women are still strongly advised by the American College of Obstetricians and Gynaecologists to consume no more than 200 mg of caffeine per day — that equates to approximately one 12-ounce cup of coffee or the standard dose in most energy drinks and pre workouts (ACOG, 2010; Brent et al., 2011).

Eating cured meats, raw eggs, or raw seafood: As mentioned above, this increases the risk of potential foodborne illnesses, which can make the mother violently ill, preventing her from consuming adequate nutrition for her baby.

More than 6 ounces of fish per week: As detailed above, this could increase the likelihood of mercury toxicity and its associated consequences.

Consuming empty calories: Getting the most nutrients for the amount of daily calories is important for optimal growth and development (Berardi & Andrews, 2015).

Smoking: Prenatal exposure to tobacco smoke is a major risk factor for increased mortality of the foetus during pregnancy (Wickstrom, 2007).


The basics of nutrition during pregnancy are not overly different from the nutrition recommended for optimal health during other life stages. The basic fundamentals of eating a calorie balanced, nutrient-dense diet are still something you should aim to achieve and will immediately take care of many of these points raised above.

With that being said, some additional attention should be paid to weight status, certain nutrient intakes and limiting or avoiding certain foods. Even if your diet has been bad in the past, it’s vitally important to fix this and eat well for these few important months.

By placing a priority on healthy eating during pregnancy, you are doing your part in ensuring that your baby has the best start in life!


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About the author


Rudy Mawer, MSc, CISSN

Rudy has a 1st class BSc in Exercise, Nutrition & Health and a Masters in Exercise & Nutrition Science from the University of Tampa. Rudy currently works as a Human Performance Researcher, Sports Nutritionist and Physique Coach. Over 7 years he has helped over 500 people around the world achieve long last physique transformations.

He now works closely with a variety of professional athletes and teams, including the NBA, USA Athletics, World Triathlon Gold Medalists, Hollywood Celebrities and IFBB Pro Bodybuilders. If you would like to get in contact or work with Rudy please contact him on social media.

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