What to Eat While Breastfeeding

Breastfeeding has its own nutritional guidance, separate from pregnancy, and it’s easy to assume the same food rules simply carry over. Some do, some relax, and a few are worth knowing about specifically because they only apply once you’re breastfeeding.

You Need More Calories, Not the Same Amount

Breastfeeding burns a genuinely significant number of extra calories — commonly estimated at around 300–500 extra calories a day for exclusive breastfeeding, more than the additional amount typically recommended in later pregnancy. This isn’t a licence to eat without any thought, but it is a reason not to restrict food intake or attempt weight-loss dieting too aggressively while establishing breastfeeding, since inadequate intake can affect both your energy levels and, in some cases, milk supply.

Most Pregnancy Food Restrictions No Longer Apply

Many of the food safety rules that apply during pregnancy — around raw fish, cured meats, unpasteurised soft cheese, and pâté — relax once you’re breastfeeding, because these restrictions exist specifically to protect a developing fetus from risks like listeria, which pass differently (or not at all) through breast milk. You can generally return to a normal diet, including these foods, once your baby is born, whether or not you are breastfeeding.

Alcohol and Caffeine Still Need Some Care

Unlike most food restrictions, alcohol and caffeine do pass into breast milk and are worth continuing to think about — see the dedicated guides on alcohol and caffeine during breastfeeding for the specifics, but broadly: caffeine is fine in similar moderate amounts to pregnancy, and alcohol is safest avoided or carefully timed around feeds rather than assumed to be fully off the table.

Foods That May Affect Your Baby

Every baby is different, and there’s no universal list of foods that cause problems, but some breastfeeding parents notice a pattern between something they’ve eaten and increased fussiness, gas, or a rash in their baby — dairy, caffeine, and strongly flavoured or gas-producing foods like onions, garlic, or cruciferous vegetables are the most commonly reported. This isn’t a reason to eliminate entire food groups pre-emptively; it’s worth only cutting something out if you notice a clear, repeated pattern, and discussing it with a health visitor or GP if you suspect a genuine sensitivity, such as a possible cow’s milk protein reaction.

Staying Hydrated

Breastfeeding increases fluid needs, and dehydration is a common, easily overlooked contributor to feeling low-energy or noticing a dip in supply. Keeping a glass or bottle of water within reach during feeds — a habit many breastfeeding parents build simply because they’re sitting still for a stretch of time anyway — is a simple, effective way to stay on top of this without needing to track exact volumes.

Key Nutrients Worth Paying Attention To

A few nutrients are worth some specific attention while breastfeeding:

• Vitamin D — the NHS recommends a 10-microgram daily supplement for breastfeeding parents, the same as during pregnancy, since it’s difficult to get enough from diet and sunlight alone, particularly through the autumn and winter months.
• Iodine — important for your baby’s development via your milk; found in dairy, fish, and eggs, and worth checking your prenatal or postnatal supplement includes it if your diet is low in these foods.
• Omega-3 (DHA) — found in oily fish, and thought to support your baby’s brain development through breast milk; oily fish portion guidance during breastfeeding is broadly similar to pregnancy (up to two portions a week).
• Iron — particularly relevant if you lost a significant amount of blood during birth; red meat, pulses, and fortified cereals are good dietary sources, and it’s worth mentioning ongoing tiredness to your GP or midwife in case supplementation is needed.

Vegetarian and Vegan Diets While Breastfeeding

A well-planned vegetarian or vegan diet can meet breastfeeding nutritional needs, but it’s worth being particularly attentive to vitamin B12 (found almost exclusively in animal products, so vegans typically need a supplement), iodine, and DHA, none of which are easy to obtain from a plant-based diet alone without some planning or supplementation. Speaking with a GP or dietitian about a tailored supplement plan is a sensible step if you’re breastfeeding on a vegan diet.

When to Seek Advice

If you have ongoing concerns about your diet’s effect on your milk supply, your own energy levels, or your baby’s reaction to something you’ve eaten, a health visitor, GP, or breastfeeding support service is the right first point of contact — most day-to-day dietary questions during breastfeeding don’t require anything more restrictive than a normal, varied, adequately fuelled diet.