Breastfeeding Diet. What to Eat While Breastfeeding

Your baby is tasting your dinner. In a US study, some mothers drank carrot juice during pregnancy or while breastfeeding. Later, their babies made fewer unhappy faces when they first tried carrot-flavoured cereal.

Flavours from your food pass into your milk. So a varied breastfeeding diet may help your baby accept new foods later.

There is more. Breast milk contains special sugars that your baby cannot even digest. They are there to feed your baby’s gut bacteria. I strongly believe gut health plays a major role in nearly every health condition, and it starts this early.

In this guide I cover what to eat while breastfeeding and which popular advice is a myth. I also share how to look after your own gut and energy.

Your milk feeds your baby’s gut

After lactose and fat, special sugars called human milk oligosaccharides are the third largest part of breast milk. Babies cannot digest them. Instead, they feed helpful bacteria in the baby’s gut.

In a 2020 study, researchers changed what breastfeeding mothers ate for short periods. The levels of these milk sugars changed with the mother’s diet. In turn, that changed the bacteria in the milk.

It was a small study, and we do not yet know the best diet for these sugars. But it shows that your food reaches your baby in more ways than calories.

How much extra food do you need?

The US Centers for Disease Control and Prevention says most well-nourished breastfeeding mothers need about 330 to 400 extra calories a day. That is roughly one extra small meal or two healthy snacks.

Needs vary with your body, your activity and how much your baby feeds. Hunger is a good guide in the early months.

Try this. Keep easy snacks within reach of your feeding chair. Think a banana, nuts, yogurt, cheese with whole grain crackers or hummus with vegetables.

Myth. Drinking more water makes more milk

This advice is everywhere. But a Cochrane review found no good trials showing that extra fluids increase milk supply. The one study they found reported no gain in milk from drinking more.

You do need to stay hydrated, and many mothers feel very thirsty while feeding. Drink to your thirst, but you do not need to force extra litres.

Try this. Keep a glass of water next to you at every feed. Pale yellow urine is a good sign you are drinking enough.

The nutrients that matter most

The CDC says your needs for several nutrients go up while breastfeeding. Here are the ones that matter most.

• Protein. Have some at every meal. Eggs, fish, chicken, beans, lentils, tofu, yogurt and cheese all count.
• Iodine. You need 290 micrograms a day for your baby’s brain development. Dairy, eggs, seafood and iodised salt are good sources.
• Choline. You need about 550 mg a day. Eggs are one of the richest sources.
• Vitamin B12. It comes mainly from animal foods. If you are vegan, you will almost certainly need a supplement.
• Omega-3 fats. Fish low in mercury, like salmon, sardines and trout, give DHA for your baby’s brain and eyes.
• Vitamin D. Breast milk is low in it, so most breastfed babies need drops. Ask your doctor about you and your baby.

Try this. Ask your doctor if you should keep taking your pregnancy multivitamin while breastfeeding. Many mothers benefit from it.

Surprising finding. A mother’s vitamin D can cover her baby

In a US trial, breastfeeding mothers took either 400 IU or 6,400 IU of vitamin D a day. When mothers took the high dose, their babies’ vitamin D levels were as good as babies who got drops directly.

This is interesting, but it is not a reason to start high doses on your own. Please decide on vitamin D with your doctor.

Fish, yes. High-mercury fish, no

Fish is great food for breastfeeding mothers. But mercury can pass into breast milk.

The US Food and Drug Administration lists the best choices. These include salmon, sardines, cod, tilapia, trout and canned light tuna. It advises avoiding king mackerel, shark, swordfish and bigeye tuna.

Try this. Eat two or three servings a week of low-mercury fish.

Coffee and alcohol, the honest answers

Coffee is usually fine. The CDC says up to 300 mg of caffeine a day, about 2 to 3 cups of coffee, does not usually affect babies. Very high intakes have been linked to fussy, jittery babies who sleep poorly.

Alcohol is different. The CDC says not drinking is the safest choice. If you do drink, keep it to one standard drink in a day. Then wait at least 2 hours before you breastfeed.

Lactation cookies and fenugreek, the evidence

Many mothers try herbs like fenugreek, or lactation cookies and teas, to boost milk. A Cochrane review looked at 41 trials of these and similar products.

Some natural products seemed to help a little. But the certainty of the evidence was low to very low. Many of the studies had serious flaws.

The strongest signal for more milk is still your baby. Frequent feeding, a good latch and enough rest matter most.

Try this. If you worry about your supply, see a lactation consultant before buying products. Herbs can interact with medicines, so check with your doctor first.

Do you need to avoid allergy foods?

Many mothers cut out peanuts, eggs or dairy to protect their baby from allergies. In 2019, the American Academy of Pediatrics reviewed the research. It found no good evidence that avoiding these foods while breastfeeding prevents allergies.

Cutting out foods without a reason can make your own diet poorer. Your baby may show signs of an allergy, like blood in the stool, eczema or vomiting after feeds. If so, see your doctor before you change your diet.

Many mothers are also told to avoid beans, cabbage or spicy food. Most babies cope well with them. If you see a clear pattern, talk to your doctor before you cut out whole food groups.

Losing baby weight while breastfeeding

A US trial was published in the New England Journal of Medicine. Breastfeeding mothers with overweight ate about 500 fewer calories a day and exercised regularly for 10 weeks. They lost about 4.8 kg, or 10.5 pounds.

Their babies grew just as well as babies of mothers who did not diet. That rate was about half a kilo, or 1 pound, a week.

Try this. Wait until breastfeeding is well set up. In the trial, mothers started at about four weeks after birth. Then aim for slow, steady loss. Avoid crash diets, which can affect your energy and mood.

Look after your own gut too

Constipation is common after birth. Iron tablets, less sleep, less movement and fear of pain after delivery all play a part.

Try this. Eat oats, beans, lentils, fruit and vegetables every day. Add plain yogurt or kefir. Drink to your thirst and take short walks when you feel ready.

A simple day of eating while breastfeeding

• Breakfast. Eggs on whole grain toast with tomatoes, or oats with yogurt and berries.
• Snack. A banana and a handful of nuts.
• Lunch. Lentil soup or a chicken and bean salad with olive oil.
• Snack. Hummus with carrot sticks, or cheese with crackers.
• Dinner. Salmon or tofu with brown rice and plenty of vegetables.
• Night feeds. A glass of milk or kefir, or a small bowl of cereal.

Frequently asked questions

Do I need to eat for two while breastfeeding?

No. Most mothers need about 330 to 400 extra calories a day. That is closer to one extra small meal than a second full diet.

Which foods increase breast milk?

No food is proven to boost milk supply in a big way. Frequent feeding or pumping is the strongest signal for your body to make more.

Can I drink coffee while breastfeeding?

Yes, in moderation. The CDC says up to 300 mg of caffeine a day, about 2 to 3 cups of coffee, is usually fine.

Can I diet while breastfeeding?

Slow weight loss of about half a kilo, or 1 pound, a week did not affect babies’ growth in a trial. Avoid crash diets and speak to your doctor first.

What I want you to remember

A good breastfeeding diet is simple. Eat a little more, eat a wide mix of real food, and drink to your thirst. Focus on protein, iodine, B12, omega-3 fats and vitamin D.

Feed yourself with the same care you give your baby. You both deserve it.