Beyond that, we hear all kinds of opinions about how and when to breastfeed, and how to increase milk supply, but there does seem to be some confusion about what is actually in it!

After delivery, the thin, yellow, colostrum milk appears. This milk contains less fat and calories (about 15 calories per ounce) than mature milk, but is a rich source of proteins, fat soluble vitamins like A, D, and E, minerals, electrolytes, components that help iron absorption, and IgA antibodies which peak during the first week of life. Transition milk begins at about 7 to 14 days post partum. This milk, like mature milk, contains less immune antibodies and more protein, fat and calories. Mature milk also offers a supply of healthy bacteria, anti-inflammatory substances, hormones, and components that help with growth and digestion.

Mature milk arrives at about two weeks after birth, continuing through seven to eight months of life. Breastfeeding moms on average produce about 750 milliliters or 25 ounces of mature milk per day. This amount of breast milk provides babies with approximately 495 calories per day. The nutrient breakdown is 6% protein (80% whey protein and 20% casein), 39% carbohydrate in the form of lactose, and 55% fat. The type of fat varies depending on the mother's diet. In the west, typically the fat content in breast milk is lowest in early morning and increases during the day.

Nursing moms and everyone else should avoid trans fatty acids and foods high in saturated fat, and rather eat foods high in unsaturated fats such low mercury fish, olive oil, avocados, nuts, and seeds. DHA, an omega 3 fatty acid found in cold water fish and fortified eggs, is vital to for infant mental and retinal development. Breastfeeding moms can directly increase the DHA content in their breast milk if they regularly eat these foods or take a DHA supplement.

Other nutrients in breast milk sensitive to the mother's diet are vitamins A, E, D, B12, C, riboflavin, and minerals such as selenium, iodine, fluorine, and zinc. Calcium content in breast milk is not related to the mother's diet. During breastfeeding, the mother's bone deposits supply the necessary calcium for the baby, which is rapidly replenished after weaning.

Breast milk volume and composition may be highly variable between different mothers, however in general, the volume of breast milk will decrease if the mother's diet is too low in calories, fat and protein.

In a nutshell, to maximize the nutrient content in your breast milk:

1. Eat a healthy diet with about 200 extra calories per day than when you were pregnant.
2. Eat a daily diet of whole foods rich in protein, healthy fats and whole grains.
3. Keep taking your prenatal supplement and DHA.
4. Drink plenty of fluids.