Breastfeeding Nutrition: What to Eat While Nursing

Breastfeeding is one of the most nutritionally demanding things the human body does. You're producing milk around the clock — a fluid that requires significant energy, protein, fat, and micronutrients drawn largely from your own stores. Yet nutrition guidance for breastfeeding women is often oversimplified, leaving many mothers confused, exhausted, and unnecessarily restrictive.

This guide is designed to give you a practical, evidence-based roadmap for fuelling both yourself and your baby during the breastfeeding period.

How Many Extra Calories Do You Actually Need?

The current evidence suggests breastfeeding women need approximately 400–500 extra calories per day above pre-pregnancy maintenance needs, though this varies based on milk volume, body composition, and activity level.

These calories are best delivered through nutrient-dense wholefoods rather than processed options. Think of it as an opportunity to nourish, not just fuel.

Important: If you're also pursuing postpartum weight loss, extreme caloric restriction (below 1,500–1,800 calories for most women) can impair milk production and leave you depleted. Work with a dietitian to find the right balance.

Key Nutrients for Breastfeeding Women

Protein

Protein needs are elevated during lactation — aim for at least 1.5–1.7g per kg of body weight per day. Protein supports tissue repair, helps with satiety, and is a building block of breast milk. Include protein at every meal: eggs, fish, poultry, legumes, tofu, dairy, or quality protein supplements if needed.

Omega-3 Fatty Acids (DHA)

DHA is critical for infant brain and eye development, and it transfers via breast milk. Aim for 200–300mg of DHA per day. Best sources include oily fish (salmon, sardines, mackerel), omega-3 enriched eggs, and a high-quality algae-based supplement (preferred over fish oil for heavy metal safety).

Iodine

Iodine is essential for thyroid function and infant neurological development. Breastfeeding women need 270 micrograms per day — significantly more than the general population. Sources include seaweed, dairy, eggs, and seafood. A postnatal supplement containing iodine is recommended for most women.

Calcium

During lactation, calcium is mobilised from your bones if intake is inadequate. Aim for 1,000mg per day via dairy, fortified plant milks, sardines (with bones), tofu made with calcium sulfate, almonds, and leafy greens such as kale and bok choy.

Iron

While menstruation is typically suppressed during breastfeeding, iron stores may still be depleted from birth losses. Fatigue that's disproportionate to sleep deprivation can be a sign of iron deficiency — get your levels checked at your 6-week appointment if you haven't already.

Vitamin D

Breast milk is generally a poor source of vitamin D, and most women are deficient regardless of breastfeeding status. Supplementing with 1,000–2,000 IU per day is widely recommended. Speak to your GP about testing if you have concerns.

Foods to Include More Of

• Oily fish (2–3 serves per week): salmon, sardines, trout, mackerel

• Dark leafy greens: spinach, kale, silverbeet — rich in calcium, iron, and folate

• Legumes: lentils, chickpeas, black beans — iron, protein, fibre

• Whole grains: oats, quinoa, brown rice — sustained energy

• Dairy or fortified plant alternatives: calcium and iodine

• Eggs: protein, choline, DHA, vitamin D

• Nuts and seeds: healthy fats, zinc, magnesium

• Colourful vegetables and fruits: antioxidants, vitamin C, fibre

  
  

Supplements to Consider

• Postnatal multivitamin: look for one containing iodine, choline, folate (as methylfolate), and vitamin D

• Algae-based DHA: 200–300mg daily

• Vitamin D: 1,000–2,000 IU daily (or as guided by blood results)

• Iron: only if deficiency is confirmed by testing

  
  

The Bottom Line

Breastfeeding nutrition doesn't need to be complicated, restrictive, or stressful. Focus on eating a variety of whole, nutrient-dense foods, stay well hydrated, and supplement strategically. If you're struggling — whether with supply, energy, or knowing what to eat — a postpartum dietitian can provide tailored guidance.