Nutrition in Pregnancy and Breastfeeding

From the moment you learn you are pregnant, everyone has advice: “You must eat for two now”, “eat whatever you fancy or it will leave a mark on the baby”, “give up coffee completely”, “don’t eat fish”. A good deal of this well-meant advice is either incomplete or wrong, and does little more than confuse the mother-to-be.

Nutrition in pregnancy and breastfeeding directly affects the mother’s health and the baby’s development; it is also the most effective way to ease complaints of this period such as nausea, constipation and heartburn. On this page we explain how much weight should be gained in pregnancy, eating by trimester, the key nutrients, foods to avoid, gestational diabetes and the breastfeeding period.

Why is nutrition so important in pregnancy?

The baby’s organs, bones and brain develop from the nutrients in the mother’s blood. When the mother does not take in enough, the baby meets part of its needs from the mother’s stores; this can lead to anaemia, tiredness and bone loss in the mother. Nutrition also affects gestational diabetes, raised blood pressure in pregnancy and the baby’s birth weight.

The belief in “eating for two”, however, does not reflect reality. Energy needs do not rise in pregnancy as much as people think; what really rises is the need for vitamins, minerals and protein. In other words, it is not the size of the plate but its quality that needs to increase.

How much weight should you gain in pregnancy?

The recommended weight gain is not the same for everyone; it is set according to body weight before pregnancy. For a woman who begins pregnancy at a normal weight, a gain of around 11–16 kilos is generally considered appropriate. A little more is recommended for women who start underweight and less for those who start overweight. The targets are different in twin pregnancies.

The timing of weight gain matters too. In the first three months the gain is very small, and some weight may even be lost because of nausea. Most of the gain takes place in the second and third trimesters. Energy needs follow the same course: in the first trimester almost no extra energy is needed; in the following months the extra required is roughly one snack a day. The range that is right for you is determined together with your doctor’s monitoring.

Nutrition in pregnancy by trimester

The first trimester

The foundations of the baby’s nervous system and organs are laid in this period; the need for folate is at its most critical. It is also the period when nausea, sensitivity to smells and loss of appetite are at their strongest. Rather than looking for a perfect diet, the aim is to build small, frequent meals from the foods that can be tolerated.

The second trimester

Nausea usually eases and appetite returns. Because the baby’s growth speeds up, the need for protein, iron and calcium increases. This is the period in which the meal pattern is settled so that weight gain progresses in a balanced way. Screening for gestational diabetes is also done at the end of this period.

The third trimester

Because the growing uterus presses on the stomach, early fullness, heartburn and constipation are common. Making meals smaller and more frequent and bringing the evening meal forward brings relief. As the baby’s brain development speeds up, it is important to include sources of omega-3.

Key nutrients in pregnancy

• Folate (folic acid): Needed for the healthy closure of the neural tube, which forms the baby’s brain and spinal cord. This structure develops in the first weeks of pregnancy, often before the woman realises she is pregnant; this is why it is recommended that folic acid be started when a pregnancy is being planned. Green leafy vegetables, pulses and oranges are natural sources.
• Iron: Because blood volume increases in pregnancy, iron needs rise markedly. Red meat, eggs, pulses and dark green vegetables are the main sources. Absorption of plant iron increases when it is eaten with a source of vitamin C; tea and coffee reduce absorption.
• Iodine: Needed for the baby’s brain development and the mother’s thyroid function. Iodised salt, dairy products, eggs and seafood are sources.
• Calcium and vitamin D: They support the baby’s bone and tooth development and protect the mother’s bone stores. Milk, yoghurt, cheese, sesame, almonds and green leafy vegetables provide calcium.
• Omega-3 fatty acids: They play a part in the baby’s brain and eye development. Two portions a week of fish low in mercury is a good source.
• Protein: Needed for the baby’s tissues, the placenta and the mother’s increased blood volume. Every main meal should include a source of protein.
• Vitamin B12: Deficiency is common in women who eat little or no animal food and must be assessed.

Supplements such as folic acid, iron and vitamin D are used in pregnancy on medical advice. Your doctor decides which supplement to take, when and for how long; multiple supplements started on your own can lead to taking more of some vitamins than is needed.

What not to eat in pregnancy: foods to avoid and limit

• Raw and undercooked meat, chicken and eggs: Raw meatballs, rare steak, uncooked cured meats and soft-boiled eggs carry a risk of infection.
• Unpasteurised milk and cheeses made from it: Pasteurised products should be chosen instead of raw milk sold loose and farmhouse cheeses.
• Raw seafood and fish high in mercury: Raw fish and shellfish, and large predatory fish such as swordfish, are avoided. Anchovy, sardine, salmon, sea bass and sea bream are options that can be eaten safely.
• Alcohol: No amount of alcohol is considered safe in pregnancy.
• Too much caffeine: There is no need to give up coffee altogether; it is recommended that total daily caffeine be kept at a level that does not exceed two cups of filter coffee. Remember that tea, cola and chocolate also contain caffeine.
• Liver and offal: Limited, especially in the first months, because of their very high vitamin A content.
• Herbal teas: Being natural does not mean being safe. Some herbs can affect uterine contractions; consult your doctor before drinking them regularly.
• Poorly washed vegetables and fruit: Wash them in plenty of water against soil-borne parasites, and take care when eating raw salad outside the home.

Nutrition for common complaints in pregnancy

Nausea and vomiting

Nausea is worse on an empty stomach. Eating a few crackers or roasted chickpeas before getting out of bed in the morning, making meals smaller and more frequent, taking fluids between meals and staying away from strong-smelling, fatty foods all help. Cold and lukewarm foods are easier to tolerate because they give off less smell than hot dishes.

Constipation

Hormones that slow bowel movement, and iron supplements, can cause constipation. Increasing fibre with vegetables, fruit, pulses and whole grains, drinking enough water and walking every day are effective. Dried apricots and prunes are practical options.

Heartburn and reflux

Small portions, not lying down for at least two hours after eating, eating the evening meal early and cutting down on fatty, fried and very spicy foods ease the complaint.

Swelling

Mild swelling of the feet is common in the last months of pregnancy. Cutting out salt completely is not recommended; moderate salt use, enough fluid and movement are sufficient. If swelling starts suddenly and also affects the face and hands, see a doctor straight away.

Gestational diabetes and nutrition

Pregnancy hormones reduce the effect of insulin; in some women the pancreas cannot meet the increased demand and blood sugar rises. Screening is usually carried out by the doctor between the 24th and 28th weeks of pregnancy. When the diagnosis is made, the first step of treatment is nutrition.

In gestational diabetes the aim is not to cut out carbohydrates but to spread them evenly through the day. Carbohydrates are divided between three main meals and two or three snacks and eaten with protein and fibre at each meal; fruit juice, desserts and white-flour products are limited. Blood sugar is measured as often as the doctor specifies, and the plan is adjusted to those readings. If target values are not reached with diet and activity, the doctor may decide on medication. For more on blood sugar balance, see the nutrition for insulin resistance page.

Nutrition while breastfeeding

Producing milk takes energy; a breastfeeding mother’s need for energy and fluid is even higher than in pregnancy. The need for protein, calcium, iodine, B12 and omega-3 remains high. The mother’s diet affects the level of some vitamins and fatty acids in milk more than the amount of milk.

The most important factor determining the amount of milk is the baby feeding often and effectively. No particular food has been shown to increase milk on its own. Drinking enough fluid, not skipping meals and resting support milk production; the belief that sugary foods such as sherbets and desserts increase milk only comes back to the mother as extra weight.

Nor is it true that every “gassy” food the mother eats will give the baby wind. There is no need to ban foods such as pulses or cabbage in advance. If the baby shows marked restlessness, bloody stools or a rash, the assessment is made by a paediatrician. Caffeine can be consumed in moderation; staying away from alcohol is the safest option.

Losing weight after birth: can you diet while breastfeeding?

The first weeks after birth are a recovery period, and there should be no rush to lose weight. Because breastfeeding itself uses energy, many mothers who eat a balanced diet lose weight on their own in the first months. After that, slow and gradual weight loss does not harm milk production.

Very low calorie diets, and those that skip meals or rely on a single food, are not recommended while breastfeeding: they increase the mother’s tiredness and drain her nutrient stores. In this period the plan is built realistically around the baby’s sleep pattern, practical meals the mother can eat with one hand and the sweet cravings created by lack of sleep. For the period after birth, see the weight management page, and for mothers who find it hard to leave the house, the online nutrition counselling page.

Common mistakes in pregnancy and breastfeeding

• Eating for two: Excess weight gain increases the risk of gestational diabetes and high blood pressure and makes it harder to lose weight after birth.
• Eating too little to avoid gaining weight: Pregnancy is not a time for weight loss; restrictive diets can affect the baby’s development.
• Avoiding fish altogether: When the right types are chosen, fish is one of the most valuable foods of pregnancy.
• Taking supplements on your own: More than one product may contain the same vitamin, and too much can be harmful.
• Treating cravings as unlimited permission: Eating what you fancy in moderation is not a problem; meeting cravings with dessert or pastries every day affects blood sugar and weight.
• Turning to sugary drinks to increase milk: It is frequent feeding and enough fluid, not sugar, that increase milk.

When should you see a doctor?

• Vomiting many times a day, being unable to keep fluids down and losing weight
• Sudden headache, visual disturbance, swelling of the face and hands
• Excessive thirst, passing urine often and marked weakness
• A desire to eat non-food substances such as soil, ice or chalk
• Fever and diarrhoea after eating raw or suspect food

Frequently asked questions

Can you drink coffee in pregnancy?

Yes, in moderation. It is recommended that daily caffeine intake does not exceed two cups of filter coffee; the caffeine in tea, cola and chocolate counts towards this total.

Can you eat fish in pregnancy?

Yes, and it is recommended. Well-cooked fish low in mercury can be eaten twice a week. Raw fish and large predatory fish are avoided.

Are cravings a sign of a nutrient deficiency?

Most cravings have to do with hormonal changes and altered senses of smell and taste. A desire for non-food substances such as soil or ice, however, may be linked to iron deficiency and should be reported to the doctor.

I started pregnancy overweight. Can I lose weight while pregnant?

Weight loss is not a goal in pregnancy. For women who start overweight, the aim is to keep weight gain within the recommended limits and to improve the quality of the diet.

Which foods increase milk while breastfeeding?

No food has been proven to increase milk on its own. Feeding often, drinking enough fluid, not skipping meals and being able to rest are the basic supports of milk production.