A: Congratulations on breastfeeding and giving your baby a healthy start. Breast milk is naturally designed to have the right consistency to meet a baby's nutritional needs. If you eat well, drink enough fluids and get plenty of rest, your breasts will produce the quantity and content of breast milk that's right for your baby.

And as you observed, the consistency of breast milk changes over time. It changes as the baby gets older, and it changes over the course of each feeding.

As your baby grows, his nutritional needs for protein, fat and minerals in breast milk change. The milk during the first few days of life, called colostrum, is in small quantities, thick and yellowish. It is high in protein, including antibodies to protect the baby from illnesses, and low in fat and sugar. The colostrum also acts as a natural laxative to help the baby pass the first bowel movement, called meconium. After the second or third day of life, the mature milk comes in and the breasts fill with larger quantities of thinner, clearer milk. Over the baby's first year, the consistency of your milk can continue to change slightly.

During each feeding, your breasts begin by producing the foremilk, which is thinner and watery, with a light blue color. This milk helps satisfy the baby's thirst. After several minutes of nursing, your breasts begin to produce the hindmilk, which is thicker and creamy, sometimes with a yellowish color. The hindmilk is higher in fat, helps satisfy your baby's hunger and helps your baby gain weight over time. The hindmilk also makes your baby feel full and sleepy, which helps signal the end of feeding on each breast.

The color of breast milk can also vary based on a woman's diet. If a woman eats a lot of yellow vegetables such as yams, squash and carrots, the carotene in the vegetables can make the milk yellowish (this is still considered safe for the baby). If a woman eats foods or drinks beverages with food dyes (such as sodas, sports drinks and gelatin), it can tinge the milk pink, orange or green, depending on the color of the dye. Some medications can also change the color of breast milk.

If you have any questions or concerns about your breast milk, call your doctor or contact La Leche League (www.laleche.org ).