Most foods are perfectly fine to eat while breastfeeding, and there’s no long list of things you need to cut out. The short list of foods that genuinely matter includes high-mercury fish, excessive caffeine, and alcohol. Beyond that, the only reason to remove a food from your diet is if your baby is showing specific signs of a sensitivity. The old advice to avoid peanuts, spicy foods, or gassy vegetables “just in case” is outdated.
High-Mercury Fish
Mercury is the one dietary toxin that clearly passes into breast milk and can affect your baby’s developing nervous system. The FDA recommends completely avoiding seven types of fish with the highest mercury levels: king mackerel, marlin, orange roughy, shark, swordfish, Gulf of Mexico tilefish, and bigeye tuna.
This doesn’t mean you should skip fish entirely. Fish is one of the best sources of omega-3 fatty acids, which support your baby’s brain development. The FDA recommends eating two to three servings per week of lower-mercury options like salmon, shrimp, tilapia, cod, and canned light tuna. A serving during breastfeeding is about 4 ounces, roughly the size of your palm.
Caffeine
Caffeine does transfer into breast milk, and newborns process it much more slowly than adults. Most experts, including the American College of Obstetrics and Gynecology, consider 200 to 300 milligrams per day safe. That’s roughly two to three cups of brewed coffee. The CDC puts the threshold at about 300 milligrams.
If you’re drinking more than that, your baby may show signs of overstimulation: trouble falling or staying asleep, jitteriness, increased fussiness, or difficulty latching and staying focused during feeds. Newborns and preemies are more sensitive than older babies, so you may want to stay on the lower end in those early weeks. If your baby seems unusually restless or isn’t sleeping well, cutting back on caffeine is a reasonable first step.
Alcohol
Alcohol passes freely into breast milk at roughly the same concentration as your blood alcohol level, then drops as your body clears it. The CDC’s guidance is straightforward: not drinking is the safest choice, but up to one standard drink per day is not known to be harmful to the infant. More than one drink per day is not recommended.
If you do have a drink, wait at least two hours before nursing. That window gives your body time to metabolize the alcohol and bring levels in your milk back down. If you have two drinks, wait four hours. Pumping and dumping doesn’t speed this up, since alcohol leaves your milk as it leaves your blood. Timing a drink right after a feeding session gives you the longest natural window before the next one.
Pregnancy Food Restrictions Don’t Apply
One of the most common questions new parents have is whether pregnancy rules about sushi, deli meat, and soft cheeses still apply. They don’t. Those restrictions exist because infections like listeria can cross the placenta and harm the fetus. Once you’ve delivered, foodborne pathogens are no longer transmitted to your baby through breast milk. Sushi, undercooked eggs, soft cheeses, and deli meats are all considered safe while breastfeeding, as long as you’re following normal food safety practices.
The one overlap with pregnancy guidelines is mercury in fish, which remains relevant because mercury does pass into milk.
Gassy Foods and Spicy Foods
Broccoli, cabbage, beans, onions, and garlic have a reputation for making breastfed babies gassy. The evidence behind this is weak. Texas Children’s Hospital notes that no specific foods have been proven to cause gas in breastfed infants. The gas you feel after eating cruciferous vegetables comes from fiber being fermented in your own gut. That gas doesn’t enter your bloodstream or your milk.
Some mothers do notice their babies seem fussier after certain meals, but controlled research hasn’t confirmed a reliable pattern. Many babies tolerate these foods without any issue. Unless you’re seeing a consistent, repeatable reaction in your baby, there’s no reason to preemptively cut out vegetables, beans, or spicy foods. In fact, research shows that flavors from garlic, carrots, mint, and other foods do transfer into breast milk, and repeated exposure during breastfeeding can actually increase your baby’s acceptance of those flavors when they start solid foods later.
Herbs That May Reduce Milk Supply
A few culinary herbs have a reputation for decreasing breast milk production when consumed in large amounts. Sage is the most commonly cited, along with peppermint, parsley, chasteberry, and jasmine. None of these have been rigorously studied in breastfeeding mothers, so the evidence is largely anecdotal.
A pinch of sage in a recipe or an occasional peppermint tea is unlikely to cause a noticeable drop in supply. The concern is more about concentrated forms: drinking multiple cups of sage tea daily, for example, or taking herbal supplements with these ingredients. If you’re struggling with low supply, it’s worth checking ingredient labels on herbal teas you drink regularly.
When Your Baby Has a True Food Sensitivity
About 2 to 3 percent of breastfed infants develop a sensitivity to cow’s milk protein in their mother’s diet. This is the most common food-related issue in breastfeeding, and it looks different from normal fussiness. Signs include streaks of blood or mucus in the stool (often appearing in the first two to eight weeks of life), persistent eczema, vomiting after feeds, or significant discomfort that goes beyond typical infant gas. In more severe cases, babies may have watery or bloody diarrhea, extreme lethargy, or poor weight gain.
If your pediatrician suspects a cow’s milk protein allergy, the standard approach is an elimination diet. You remove all dairy from your diet for two to four weeks. The proteins clear from your milk within a few days, but your baby’s gut may take longer to heal, which is why the full trial period matters. Soy is often eliminated at the same time, since many babies who react to cow’s milk also react to soy protein.
The University of Rochester Medical Center outlines two approaches. You can eliminate dairy, soy, and eggs all at once, then reintroduce them one at a time after symptoms improve. Or you can remove one food category at a time, giving each a two-to-four-week trial before moving on. If symptoms don’t improve after four weeks of elimination, the issue likely isn’t food-related.
Don’t Avoid Allergens Preventively
Older guidelines used to recommend that breastfeeding mothers avoid peanuts, tree nuts, and other common allergens. That advice has been reversed. Current evidence suggests that eating these foods while breastfeeding may actually help reduce your baby’s risk of developing allergies. Animal research published in the Journal of Allergy and Clinical Immunology found that low-dose peanut exposure during pregnancy and lactation reduced the risk of peanut allergy reactions in offspring. While this hasn’t been replicated perfectly in human trials, no major medical organization now recommends allergen avoidance during breastfeeding unless your baby has already shown signs of a reaction.
Eating a varied diet that includes common allergens like peanuts, eggs, wheat, and fish exposes your baby to small amounts of these proteins through your milk. This early exposure appears to promote tolerance rather than sensitization.