Breastfeeding is best for babies and provides them with all the nutrients they need for a healthy growth and development. Exclusive breastfeeding is recommended for six months. After the introduction of foods at six months of age, recommendations include continued breastfeeding until one to two years of age or more. In preparation for and during breastfeeding, the mother’s diet should be balanced and contain sufficient key nutrients. Combining breast and bottle feeding in baby’s first weeks of life may reduce the mother’s supply of breast milk, and reversing a decision not to breastfeed is difficult. When mothers do not breastfeed, an infant formula may be used according to health professionals' advice. Improper preparation of an infant formula may lead to health hazards.