Breastfeeding - Breast Milk is Best Milk

The exact properties of breast milk are not entirely understood, but the nutrient content of mature milk is relatively stable. Its ingredients come from the mother's food supply and the nutrients in her bloodstream at the time of feeding. If that is not enough, nutrients come from the mother's bodily stores. Some studies estimate that a woman who breastfeeds her infant exclusively uses 500–600 more calories a day just producing milk for her offspring.

The exact composition of breast milk varies from day to day, and even hour to hour, depending on both the manner in which the baby nurses and the mother's food consumption and environment, so the ratio of water to fat fluctuates.

Foremilk, the milk released at the beginning of a feed, is watery, low in fat and high in carbohydrates; hindmilk, which is increasingly released as the feed progresses is creamier. There is no sharp distinction between foremilk and hindmilk, the change is very gradual. Research from Peter Hartmann's group tells us that fat content of the milk is primarily determined by the emptiness of the breast—the less milk in the breast, the higher the fat content. The breast can never be truly "emptied" since milk production is continuous.