Diet during pregnancy: nutritional needs and useful supplements

Do I need to eat for two when pregnant?

No. Energy needs increase only moderately, and mainly in the second and third trimesters. What matters is the quality of your diet: three meals a day, possibly one or two snacks, and varied, minimally processed foods.

• Starchy foods at every meal, preferably wholegrain (bread, pasta, rice, pulses).
• Fruit and vegetables at every meal, well washed.
• Protein: well-cooked meat, fish or eggs, once or twice a day, and pulses.
• Pasteurised dairy products, two to three a day.
• A variety of fats, favouring rapeseed and walnut oils.
• Water as much as you like; sugary drinks only occasionally.

Calcium comes mainly from dairy products, some mineral waters, green vegetables and almonds. If you do not eat dairy, let your doctor know: an adjustment or a supplement can be discussed. To limit constipation, which is common in pregnancy, choose fibre-rich foods and stay well hydrated.

This advice is part of pregnancy care, presented on our page Giving birth in Paris. Your doctor adapts it to your starting weight, your habits and any medical conditions.

Which vitamins and supplements should I take during pregnancy?

The effectiveness of folic acid is proven: in a Cochrane review, supplementation around conception reduced the risk of a neural tube defect by about two thirds (De-Regil et al., 2015). A diet rich in folates (green vegetables, pulses, citrus fruit) is not enough to reach the protection needed.

The French National Authority for Health (HAS) advises against routine iron: without a deficiency, it benefits neither mother nor baby and can cause side effects. A deficiency is looked for from early pregnancy, with a full blood count if needed. Avoid "pregnancy" supplements taken without advice: some contain high doses of vitamin A, which is toxic to the baby, or untested herbal ingredients.

What foods should I avoid during pregnancy?

Two food-borne infections can be serious for the baby: listeriosis and toxoplasmosis.

To prevent listeriosis

• Avoid raw-milk cheeses (except hard cooked cheeses such as Comté or Gruyère, without the rind), raw or jellied cured meats, rillettes, foie gras and pâtés.
• Avoid raw or smoked fish, raw shellfish, surimi and taramasalata.
• Reheat leftovers thoroughly and respect use-by dates.

To prevent toxoplasmosis (if you are not immune)

• Eat meat well cooked.
• Wash fruit, vegetables and herbs carefully.
• Wear gloves for gardening and for the cat's litter tray.

Details in our article on preventing toxoplasmosis.

Other precautions

• Alcohol: no alcohol at all throughout pregnancy, as no amount is risk-free for the baby's brain.
• Coffee and tea: in moderation; limit energy drinks.
• Fish: two portions a week, including one oily fish, but limit large predatory fish (swordfish, shark, tuna), which are high in mercury.
• Soya and phytoestrogens: limit them.
• Smoking: stopping is beneficial at any stage; in France, free help is available (Tabac info service, 39 89).

How much weight should I gain during pregnancy?

The recommended weight gain depends on your weight before pregnancy, measured by your body mass index (BMI). The most widely used benchmarks are those of the US Institute of Medicine (IOM, 2009):

These figures are guides, not strict targets. Gaining too much weight increases the risk of gestational diabetes and a large baby; gaining too little increases the risk of low birth weight. Weight-loss diets are not advised during pregnancy. Your weight is checked at every appointment. Regular, moderate physical activity, such as walking or swimming, helps control weight gain and remains recommended unless there is a medical reason not to.

When does my pregnancy diet need adjusting?

• Gestational diabetes: diet is the basis of treatment, with support from a dietitian. See our article on diabetes during pregnancy.
• Vegetarian or vegan diet: possible with monitoring; vitamin B12 is essential for vegans, and iron, iodine, calcium and omega-3 need checking.
• After weight-loss surgery: vitamin tests and specialist nutritional follow-up before and during pregnancy.
• Twin pregnancy: higher needs, to be adjusted with the team; the recommended weight gain is greater than with one baby.
• Severe nausea in the first trimester: eat small, frequent meals; see a doctor if you can no longer keep fluids down.

An appointment with a dietitian can be prescribed if needed.

When should I see a doctor quickly about diet-related symptoms?

See your doctor or the maternity unit if you have:

• vomiting that stops you keeping down water or food, or rapid weight loss;
• a fever, especially after eating a high-risk food: listeriosis can feel like flu and you must be seen without delay;
• intense tiredness, breathlessness or palpitations, which may be signs of anaemia;
• intense thirst and needing to pass urine often.

Go to the emergency department of your maternity unit, or call 15 or 112 in France, or your local emergency number, if you have a fever with contractions, leaking fluid, bleeding or fewer movements from your baby.

Frequently asked questions

General information article: it does not replace a medical consultation. In an emergency, call 15 or 112 in France, or your local emergency number.