Essential Dietary Guidelines for Breastfeeding Moms: What to Eat and What to Avoid

Many new mothers are aware of the saying that a woman is "eating for two" during pregnancy, emphasizing increased nutritional needs to support the baby's growth. However, what's less commonly known is that energy requirements are actually higher during breastfeeding than pregnancy. Human breast milk is a complex, dynamic fluid, with its composition changing throughout the breastfeeding period and even between individual feeds. Its ingredients—carbohydrates, fats, proteins, vitamins, and minerals—vary based on what the mother eats, environmental influences, and the baby's needs through a feedback mechanism known as "baby backwash." For instance, if a baby begins to get sick, breast milk adapts by increasing immune cells like leukocytes to help fight infection.

During the initial six months of exclusive breastfeeding, a mother produces approximately 800 milliliters of milk daily, with an energy density of around 3 kilojoules per gram. This process requires an additional average of 2,000 kilojoules daily—roughly the energy provided by a cheese sandwich, a handful of nuts, and a banana—beyond her usual dietary intake. Notably, these increased energy needs persist even after the introduction of solid foods, as milk production typically decreases to about 600 milliliters per day in the second half of the first year, but energy requirements remain roughly the same due to depletion of fat stores.

Certain nutrients demand particular attention during breastfeeding. Protein needs, for example, increase by nearly 50%, from 0.75 grams to around 1.1 grams per kilogram of body weight daily. Iodine requirements also nearly double to 270 micrograms daily, essential for thyroid function and the baby's growth and brain development.

For optimal health, breastfeeding women should focus on consuming a diverse diet that includes high-protein foods (meat, fish, eggs, nuts, seeds, soy products, legumes), dairy or fortified alternatives, whole grains, and a variety of fruits and vegetables. Adequate hydration is equally vital, with about 2.5 liters of water daily recommended, more if the weather is hot or if engaging in physical activity.

Regarding foods to limit, mothers should be mindful that many substances in their diet pass into breast milk. For example, small quantities of carrot juice can influence a baby's taste preferences, suggesting that dietary choices can subtly impact the child's development. Alcohol should be avoided altogether, as it passes into breast milk and can affect the infant's development. If consumption is necessary, tools like the "Feed Safe" app can help estimate safe times for breastfeeding post-alcohol intake. Caffeine intake should be limited to about 200mg daily—approximately four cups of tea or a single brewed coffee—to prevent adverse effects.

Contrary to some beliefs, women do not need to eliminate common allergens from their diets to prevent allergies in their babies. Emerging research suggests that exposure to allergens through breast milk may actually help reduce the likelihood of the child developing allergies. However, some infants may react adversely if their mothers consume certain foods such as cow's milk proteins, soy, or eggs, manifesting symptoms like colic, reflux, mucus, eczema, or blood in the stool. In such cases, moms might need to modify their diets, ideally under the guidance of a specialized dietitian, for at least three weeks.

For breastfeeding mothers, four practical tips include: having a blood test to check vitamin D and iron levels, taking a recommended iodine supplement, preparing nutritious, easy-to-eat snacks for late-night feeds, and keeping water within reach during nursing sessions. Supporting new mothers with thoughtful gifts like healthy frozen meals, muffins, or a quality water bottle can also be beneficial.

Source: https://medicalxpress.com/news/2025-08-breastfeeding-diet-affect-baby.html