Breastfeeding Diet Dos and Don’ts

Mind what you consume postpartum, especially when you’re nursing
A young mother holding her new baby in the kitchen.

Postpartum and breastfeeding is a big adjustment in many respects, not the least of which is the toll it takes on your body. After months of carrying around extra weight, many mamas are more than ready to shed those extra pounds once they have their babies. But a postpartum diet is not about weight loss; it’s about properly supporting the body through a challenging time while hormones adjust and especially if you’re breastfeeding. Add to that some cautions and no-nos while baby is nursing, and you’ll give yourself and your baby the best chance to recover and grow healthy and strong together!


Maintain energy

Calories are crucial for energy, so take in healthy carbohydrates from foods like fruits, vegetables, quinoa, and oats to sustain that much-needed stamina to keep you going through those sleepless nights!

Replenish depleted nutrients

Supplementation is recommended for helping to replenish the body of the nutrients it has lost during gestation so finish off your supply of prenatal vitamins and then switch to a postnatal supplement.

Physical recovery from childbirth

Eat foods that are high in protein to help the body rebuild damaged tissue in the perineal area, from a c-section, and elsewhere in the pelvic floor. If a c-section is in the cards, follow some good nutritional practices to boost your healing, both before (if it’s planned) and after your surgery.

Keep it regular!

Drink plenty of water and maintain a diet with high-fibre foods like veggies, fruit, oats, beans, and chia to get the bowels moving and keep them in good condition to continue detoxifying the body.

Lower the risk of postpartum depression

Omega-3 fatty acids (the “good” fats that are found in fish and some seeds like flax) play a big role in brain function and can be beneficial for fighting postpartum depression as well.


Breastfeeding can burn between 200 and 500 calories a day, depending on how much milk you produce. In order to keep up a good supply of breast milk you need to maintain a calorie intake between 1800-2000 calories a day. Dipping below 1500 calories could put the milk supply at significant risk.

Mom’s body will always put its nutritional resources into breast milk quality before taking care of its own needs. For this reason, it is crucial to eat a substantial and properly balanced diet (no “dieting”!) and continue adequate supplementation in the postpartum period. Proper hydration is also key to breast milk production, as dehydration can lead to clogged milk ducts and mastitis, so drink between at least ½ and ¾ oz of water (or herbal teas) per pound of body weight per day, and more to prevent thirst. Keep that water flowing in and the milk will keep flowing out!


Breast milk is extremely gentle on a baby’s digestive system and there’s evidence to suggest that when mom eats foods with high allergen potential (like the “Big Eight”: peanuts, soy, eggs, dairy, wheat, nuts, fish, and shellfish), protective antibodies are passed along via the breast milk to the baby. This, plus the gut-friendly microbes inherent to breastfeeding, helps to develop a strong gastrointestinal tract and reduces the risk of future allergy development, making long-term and exclusive breastfeeding (at least six months) an excellent choice.

How allergy prevention works: mom presents the baby with both a problem and a solution. As mom digests a food with a high allergen potential the allergens cross into the breast milk along with the corresponding mom-made antibodies. These allergen-antibody complexes hit receptor cells in the baby’s intestine which are then passed along to an immune (dendritic) cell. The dendritic cell churns out more immune cells (T cells) specifically tailored to the allergen and then those cells go on to suppress the food allergy. Result: the b aby effectively becomes desensitized to those allergens so when they eat them later in life it may not be an issue.

This does not, however, guarantee your child will never have food allergies, which are complex and can develop (or resolve) over the course of a lifetime. It does mean that you can freely enjoy peanut butter and eggs if you yourself can tolerate them, but don’t force yourself to eat something you are allergic to for your baby. If you have an allergy, then you aren’t processing it properly and won’t pass along the correct antibodies. Keep an eye on your baby for changes in their stool or increased fussiness, possible signs that your baby is not taking so well to some of those foods.


Once pregnancy is over, the list of forbidden foods is mercifully decreased. But a few caveats still remain, again, especially if you’re breastfeeding.


While you can now eat some fish, if you’re breastfeeding you should still avoid big fish like swordfish, king mackerel, tilefish, marlin, orange roughy, ahi tuna, and bigeye tuna which tend to have higher levels of mercury. Other fish, such as wild-caught salmon, pollock, catfish, shrimp, herring, anchovies, and sardines are safe and a great source of those sorely needed omega-3s!


Caffeine can also cross the breast milk barrier, but at a much lower rate than alcohol. Approximately 1% of caffeine will pass into breast milk so new moms can safely consume up to 300 mg daily (roughly 2 cups of coffee). Caffeine, of course, isn’t only present in coffee but also black and green tea, caffeinated sodas, energy drinks, and even migraine medications. Caffeine can build up in your little one’s system so keep an eye out for wakefulness, irritability, and fussiness. Here's how to identify if you're consuming too much caffeine.


It’s okay to have a glass or two of wine, just be sure that you don’t do it while actively breastfeeding. Alcohol is secreted into breast milk and can be harmful to infants. The levels are usually highest 30-60 min after ingesting alcohol and traces of it will remain in the breast milk for up to 3 hours after.

If you are concerned that your milk may have become tainted, check out your pharmacy for Milkscreen test strips that will indicate if it’s safe or not. If you don’t have access to those, just pump and dump the milk you’ve produced after drinking, and it’s always a good idea to have a supply of clean pumped milk on hand.


Most over the counter medications are safe to take when breastfeeding but it’s always good practice to check the labels and give your doctor a call if you are concerned or if your infant develops diarrhea, fussiness or changes to their sleeping and eating habits. Also, if you are being prescribed medication, make sure the prescribing physician is aware that you are breastfeeding and discuss any possible risks with them first.


Street Drugs

Street drugs like heroin, cocaine, meth, and marijuana are all off-limits for breastfeeding moms. While the medicinal properties of marijuana (and its components: THC and CBD) are now being widely recognized, they are still not a healthy choice for an infant. THC and CBD can easily cross the breast milk barrier and may be associated with a delay in brain development.


Nicotine freely passes into breast milk and can affect your baby’s mood, sleep habits, and even their ability to gain weight. Simply being around second- or third-hand smoke (the residual chemicals that come off of clothing, furniture, and other surfaces) can cause lung and breathing problems and greatly increases your baby’s risk of SIDS (Sudden Infant Death Syndrome). Nobody should be smoking around your baby.

Your body has just gone through, and is still undergoing, profound changes, and is performing impressive tasks! Give yourself the best chance to feel good, recover sooner, and continue to do what you need to do with vigour and endurance by nurturing your body and your baby’s with healthy fuel! Before you know it, your baby will be ready for solid foods!