What to eat during pregnancy

What pregnancy actually needs

Pregnancy increases nutritional demand, though by less than most people think in the first trimester. The famous "eating for two" idea is wrong.

The calorie reality

You do not need significantly more calories in the first trimester. In the second trimester, NHS guidance suggests an additional 200 calories per day, which is roughly a banana and a yoghurt. In the third trimester, the addition is similar. The idea that pregnancy doubles your food needs is wrong. Modest, sustained increases match the actual requirement.

Protein matters more

Protein needs rise more proportionally than calorie needs. Around 70 to 90 grams of protein daily is reasonable, depending on body weight. Meat, fish, eggs, dairy, pulses, nuts and seeds all contribute. Spreading protein across meals supports better use of it. Many women undershoot on protein, particularly if morning sickness limits what they can eat.

The eating quality question

Pregnancy is when food quality starts to matter more than usual. The developing baby is built from whatever you eat. Variety in vegetables, fruits, whole grains, protein sources and healthy fats supports the wide range of nutrients needed. Ultra processed food becomes a less good choice, though occasional treats are fine.

Listening to your body

Morning sickness, food aversions, fatigue and cravings all influence what you can actually eat. In the first trimester, getting any food in that stays down often takes priority over optimising the diet. The basics matter more in the second and third trimesters when you can usually eat more normally.

What actually needs attention

A handful of specific nutrients matter more in pregnancy than in normal life. Some need supplementation, others come naturally from a varied diet.

Folic acid

Folic acid prevents neural tube defects in the developing baby. NHS guidance recommends 400 micrograms daily from before conception through to 12 weeks of pregnancy. Higher doses (5 mg) are recommended for women with specific risk factors, prescribed by a GP. Most women take folic acid as a supplement because the amounts needed are difficult to get from food alone.

Vitamin D

NHS guidance recommends 10 micrograms (400 IU) of vitamin D daily throughout pregnancy and breastfeeding. UK women often have low vitamin D, particularly in winter months. The developing baby needs adequate vitamin D for bone development. Free Healthy Start vitamins are available for eligible women through the NHS scheme.

Iron

Iron requirements roughly double in pregnancy because blood volume expands and the baby needs iron stores. Many women become iron deficient during pregnancy or in the months after birth. Antenatal blood tests check iron status. If you are flagged as low, iron supplements are recommended. Red meat, dark green vegetables, pulses and fortified cereals all contribute.

Calcium and others

Calcium needs rise slightly in pregnancy. Three portions of dairy or fortified plant alternatives daily generally meets the requirement. Omega 3 fatty acids, particularly DHA, support brain development. Oily fish (within the safety limits below) is a good source. Iodine supports thyroid function for both mother and baby. Dairy and white fish contribute.

The short list of foods that matter

A few foods are worth avoiding during pregnancy because they carry specific risks. The list is shorter than it sometimes seems.

Some cheeses

Soft mould ripened cheeses (Brie, Camembert), blue cheeses and unpasteurised cheeses can carry listeria. Hard cheeses, processed cheeses and most everyday cheeses are fine. Pasteurised cottage cheese, cream cheese and feta are safe. If you are unsure, check the label or skip it.

Raw and undercooked meat

Undercooked meat can carry toxoplasmosis and other infections. Pâté should be avoided. Cured meats like salami and chorizo carry some risk and NHS guidance suggests cooking them first if eaten, though many women eat them in moderation without issue. Cooking meat thoroughly addresses most concerns.

Some fish and seafood

Limit tuna to two medium tins per week. Avoid swordfish, marlin and shark because of mercury. Oily fish like salmon, mackerel and sardines are limited to two portions weekly for the same reason. Raw or undercooked seafood including sushi made with raw fish is generally avoided. Smoked salmon is fine because the curing process kills bacteria.

Alcohol and caffeine

NHS guidance is to avoid alcohol entirely during pregnancy. The risk increases with the amount consumed and there is no level proven safe. Caffeine is limited to 200 mg daily, roughly two mugs of instant coffee or one strong coffee. Tea, cola and chocolate also contain caffeine, which adds to the total.

How needs shift

Nutritional needs and eating patterns shift through pregnancy. Working with what each trimester actually needs is more useful than trying to follow one fixed pattern.

First trimester (weeks 1 to 12)

Calorie needs barely change but folic acid is critical. Morning sickness, food aversions and fatigue make eating difficult for many women. Eating what you can keep down matters more than optimising the diet. Small frequent meals, plain foods like crackers, ginger and avoiding strong smells often help with nausea. Speak to your midwife if vomiting is severe.

Second trimester (weeks 13 to 27)

Energy often returns and morning sickness usually settles. Around an extra 200 calories daily is appropriate. Protein needs rise. Iron stores may need attention if blood tests flag them low. This is generally the most comfortable trimester for eating well. Use the window to establish good patterns.

Third trimester (weeks 28 to birth)

Demand continues to rise. Heartburn, indigestion and pressure on the stomach can make large meals uncomfortable. Smaller frequent meals often work better. Adequate protein remains important. Iron, calcium and other nutrients continue to matter for the baby's rapid growth in this phase.

After birth and breastfeeding

Breastfeeding raises nutritional needs significantly. An extra 300 to 400 calories daily is typical. Hydration matters. Adequate protein supports milk production. Vitamin D supplementation continues. Calcium needs are at their highest. Aggressive dieting while breastfeeding can affect milk supply and is generally not recommended. Speak to your health visitor or GP about specific concerns.

More on female health

For the postpartum context, our How Hormones Change After Giving Birth covers what comes next. Iron Deficiency in Women covers a common pregnancy concern. And Why Calcium and Vitamin D Matter for Women covers two key pregnancy nutrients.