Nutrition Through Pregnancy
Article by Maya Tu, BSc ANutr
Nutrition during any pregnancy, but even when planning a pregnancy, is so important. It is vital to eat healthily to help the baby grow and develop. To begin with, it should be highlighted that although you may seem hungrier, there is actually no need to eat for two, even if you are going to have twins or even triplets (1)!
When considering how to have a balanced and nutritious diet during pregnancy, there are a lot of factors to consider. These are outlined below:
Calories
Energy intake during pregnancy is key to support maternal function but also to support foetal development. During the first and second trimester, it is not always necessary to increase calorie intake. Therefore, aim for 2000 kcal daily to meet your daily energy requirements. In the final 3 months of pregnancy (the third trimester), add an extra 200 kcal a day to support the final growth of the baby (2). When breastfeeding, it is important to remember that calorie intake actually increases again by 400-500 kcal a day.
Carbohydrates
Keeping carbohydrate intake stable helps to improve blood sugar levels and insulin output and avoid fluctuations throughout the day and night. Glucose from the carbohydrates passes onto the foetus to fuel development including brain development and function. Aim to consume 175+ g/day across your three meals, focusing on high fibre choices (3).
It is important to focus on wholegrains such as oats, quinoa, buckwheat, brown rice, millet, root vegetables such as sweet potato, beetroot, carrots, squash, legumes and pulses such as lentils as well as all other vegetables. Despite that, simpler carbohydrates such as white bread and pasta may be easier to stomach when experiencing sickness or nausea as they still provide some key nutrients and energy. You can pair them with protein and healthy fats to help slow energy release.
Fat
Fats are essential building blocks for producing hormones such as oestrogen and cortisol (4). Additionally, they are essential for maintaining calorie intake and healthy weight during pregnancy. Polyunsaturated fatty acids (PUFAs), found in seeds, nuts, oily fish and oils such as olive oil, have a really important and beneficial physiologic role for the baby during critical periods of development (4). Try to choose low fat options (unless underweight) and focus on healthy fats such as olive oil, nuts and seeds, and try to limit foods high in saturated fat such as red meat and processed foods.
Protein
Protein is needed to support maternal muscle mass and hormones as well as healthy foetal development and growth (5). Try and aim for a portion of protein twice a day. The recommended protein intake increases from 45g/day to roughly 70g/day in pregnancy (5). Some examples are shown below:
Meat (beef, lamb, turkey, chicken, duck): 3 – 5 times per week
Cooked fish (fresh tuna, salmon, mackerel, sardines): No more than twice per week
Oily fish (salmon, trout, mackerel, herring): No more than two portions per week
Fermented Soy (tempeh, tofu, natto): 2 – 4 times per week BUT check with doctor to confirm
Eggs: up to 14 per week (max 2 per day)
Raw unsalted nuts (hazelnuts, pecans, pistachio, walnuts, almonds, cashews etc): handful daily
Raw unsalted seeds (chia, pumpkin, sesame, flaxseed, poppy, sunflower etc): handful daily
Legumes e.g., chickpeas, lentils, beans – it is important to monitor how the gut behaves when consuming legumes
Fruit and Vegetables
Fruit and vegetables are anti-inflammatory and high in vitamins, minerals and fibre. An anti-inflammatory diet may be able to counteract inflammatory processes in the body whilst boosting immunity, however the exact mechanisms are unclear (6).
Brightly coloured vegetables and fruit contain ‘phytonutrients’ which are active compounds that have anti-inflammatory properties. Each plant has different phytonutrients for example, bright orange and red fruits and vegetables contain carotenoids, which aid immunity and eye health; legumes, onions and ginger contain flavonoids, which have antioxidant and anti-cancer properties; and finally, cruciferous vegetables such as broccoli and cabbage contain glucosinolates which help regulate stress responses in the body (7). Evidently, it is key to have variety and diversity in order to get a range of micronutrients needed to support pregnancy.
Aim for 5+ servings daily from a variety of brightly coloured fruits and vegetables. This may include a range of:
Vegetables: Red (tomato), blue/black (cabbage, berries), orange / yellow (peppers, lemons), white (radish, cauliflower), green (kale, spinach, greens, cabbage, broccoli, watercress)
Spices & Herbs: Cinnamon, ginger, turmeric, parsley, oregano, rosemary
Fruits: Bananas, berries, apples and citrus fruits (lemons, limes, oranges, grapefruit)
Fluids
Hydration is always key for optimal health, and it is as important during pregnancy. Try and aim for 2 litres of filtered mineral water daily.
Try drinking 400ml as soon as you wake up. 400ml before 12pm, 400ml before 3pm, then 400ml before 6pm.
Herbal teas such as echinacea, chamomile, peppermint, ginger and rosehip teas are safe to drink but try to consume no more than 4 cups per day.
It is important to remember to consume no more than 200mg caffeine a day (8). Limiting caffeine intake is important as too much caffeine has been associated with increased risk of miscarriage, however, evidence is limited and so a doctor should be consulted first (9).
Milk and Calcium
Calcium is very important to maintain maternal bone mass and aid foetal bone and teeth development (10).
Try and choose low fat options (unless underweight) and aim for 3 portions per day.
A portion may look like:
Semi-skimmed Milk: 200ml
Low-fat Greek Yoghurt: 150g
Cheese: 30g
Non-dairy calcium sources include tahini, dark green leafy vegetables, tofu, beans, sardines, almonds, dried fruit and fortified non-dairy milks. But it is important to remember that non-dairy calcium sources have lower amounts than dairy sources.
What to Avoid
During pregnancy, there are also foods that could harm the baby and so therefore they should be avoided (1):
Excessive retinol form of vitamin A can be harmful to the unborn baby.
Any supplement (especially fish oil supplements) containing fish liver oils.
Unpasteurised dairy products for example soft ripened cheeses such as Brie, Camembert and goat’s cheese. There is a risk of catching an infection from a bacterium found in these dairy products.
Raspberry leaf tea. There is limited evidence on the effects of this tea and so a doctor should be consulted first.
Raw or undercooked chicken/meat and raw or partially cooked eggs (may be found in homemade mayonnaise, mousses and ice cream). There is a risk of salmonella which can harm the baby and/or mother.
Raw seafood (including sushi and oysters). They may include harmful viruses and bacteria.
Shark, marlin and swordfish should be avoided due to high levels of mercury which could affect the nervous system of the unborn baby.
Limit canned tuna – no more than 2 portions of fresh tuna or 4 medium sized tins per week. Mercury can also be found in tuna.
Supplements
Whilst it is beneficial to have a well-balanced diet throughout pregnancy, there are also some additional nutrients that are key for preconception and pregnancy. Folic acid and vitamin D are both recommended, whilst other supplements can be taken to boost intake if required.
Folic acid is essential for neural tube development in the foetus and to prevent defects such as spina bifida. Folic acid, with a dose of 400 ug/day is recommended preconception and 12 weeks into pregnancy (11).
Vitamin D (at least 10 ug/day) should be considered (12). Vitamin D can prevent the baby from developing rickets as well as improving overall pregnancy outcomes.
Iron (at least 30 mg/day) should be considered, especially if iron levels are low (13). Iron is essential for both maternal and foetal red blood cells.
Fish oil supplements can be taken to boost omega-3 intake, especially when intake of oily fish is low (14). They are not a requirement; however, they are safe to be taken if desired. Omega-3 fatty acids are essential for foetal brain development as well as foetal retina development (14).
Prenatal probiotics can be taken once daily to aid nausea, constipation and vomiting (15). They are not a requirement but are safe to be taken if desired.
Iodine is essential for foetal and maternal thyroid hormone synthesis (16). Iodine is not a requirement but can be taken if needed.
Summary
As you can see, there are many factors to consider when planning a pregnancy, during a pregnancy and even post-pregnancy. Eating a well-balanced, nutritionally rich diet, that is colourful and diverse, is essential for both mother and baby and it is crucial to be wary of the foods that may be harmful to the baby. Remember it’s always advised to consult a medical professional before taking any supplements or changing your diet.
This blog was written by Maya Tu. Maya graduated with a First-Class Honours in BSc Nutrition and has just completed her Master's in Clinical and Public Health Nutrition, graduating with Distinction. She is a part of Jamie Oliver’s nutrition team and has a passion for childhood and sports nutrition.
References:
(1) https://www.nhs.uk/pregnancy/keeping-well/have-a-healthy-diet/
(2) https://www.nhs.uk/start4life/pregnancy/healthy-eating-pregnancy/
(3) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7071246/
(4) https://pubmed.ncbi.nlm.nih.gov/25459884/
(6) https://www.hsph.harvard.edu/nutritionsource/healthy-weight/diet-reviews/anti-inflammatory-diet/
(7) https://www.healthline.com/health/phytonutrients#benefits
(8) https://www.nhs.uk/pregnancy/keeping-well/foods-to-avoid/
(10) http://apps.who.int/iris/bitstream/handle/10665/85120/9789241505376_eng.pdf
(11) https://pubmed.ncbi.nlm.nih.gov/30064014/
(12)https://www.nhs.uk/pregnancy/keeping-well/vitamins-supplements-and-nutrition/
(13) https://www.nhs.uk/pregnancy/keeping-well/vitamins-supplements-and-nutrition/
(14) https://pubmed.ncbi.nlm.nih.gov/17486170/
(15) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3046737/