Most health authorities recommend breast milk as a baby’s sole food for the first 6 months, with continued breastfeeding alongside solid foods until at least age 2. In practice, how long babies actually nurse varies widely. About 62% of U.S. infants born in 2022 were still receiving some breast milk at 6 months, and roughly 41% were still breastfeeding at their first birthday.
What Health Organizations Recommend
The World Health Organization and UNICEF recommend exclusive breastfeeding for the first 6 months of life, meaning no other foods or liquids, including water. Starting at 6 months, babies should begin eating solid foods while continuing to breastfeed up to age 2 or beyond.
The American Academy of Pediatrics aligns closely with this guidance, also supporting breastfeeding for 2 years or longer when it works for both parent and child. These recommendations are based on the nutritional and immune benefits breast milk provides at each stage, not on an expectation that every family will follow the same timeline.
Why the First 6 Months Matter Most
Breast milk during the first half-year delivers the full range of calories, fat, protein, and immune factors a baby needs to grow. No supplemental food or water is necessary. Babies should nurse on demand during this period, as often as they want, day and night.
The protective effects of breastfeeding scale with duration. Breastfeeding for at least 2 months cuts the risk of sudden infant death syndrome (SIDS) nearly in half. The protection strengthens the longer breastfeeding continues: babies breastfed for 4 to 6 months had about a 60% lower risk of SIDS compared to those never breastfed, and those breastfed beyond 6 months saw the greatest reduction.
What Breast Milk Provides After Year One
Breast milk doesn’t become nutritionally empty after a baby’s first birthday. It still supplies fat, protein, vitamins, and immune compounds, though its composition does shift. Research shows that milk produced in the second year of lactation has slightly lower concentrations of protein and calcium compared to milk at 3 months postpartum. The differences are small, and breast milk remains a valuable supplement to a toddler’s diet of solid foods.
A large study of more than 7,500 children found that longer breastfeeding duration correlated with greater grey matter surface area in the brain, a marker linked to better performance on cognitive tasks. Children breastfed for 12 months or longer showed the greatest benefit. These associations held across different income levels and were actually stronger in families with lower socioeconomic status.
Benefits for the Nursing Parent
Breastfeeding duration also affects the parent’s long-term health. For every 12 cumulative months of breastfeeding, the risk of breast cancer drops by about 4.3%. The effect on ovarian cancer is even more striking: women who breastfed for more than 13 months total were 63% less likely to develop ovarian cancer than those who breastfed for fewer than 7 months. Women who nursed multiple children for a combined total of more than 31 months reduced their ovarian cancer risk by up to 91%.
How Long Humans Have Historically Nursed
Two years of breastfeeding can feel like a long time in modern life, but it’s actually on the shorter end of human history. Anthropological evidence from populations around the world shows that complete weaning typically happened around age 3, and sometimes much later. Prehistoric Native American communities in Central California began introducing solid foods around age 2 and completed weaning between ages 3 and 5. Ancient Mayan communities in some cases continued breastfeeding until children were 6 to 9 years old. In ancient Rome, children were commonly weaned around age 2 to 3, roughly when they began learning the alphabet.
Across cultures and time periods, supplementing with solid food by 6 months and fully weaning around age 3 appears to be the broad human pattern. Modern recommendations for breastfeeding until at least age 2 sit comfortably within this biological norm.
How Weaning Works in Practice
There’s no single correct age to stop breastfeeding. The decision depends on the child’s needs, the parent’s circumstances, and what feels right for both. Some babies lose interest on their own. Others would happily continue well into toddlerhood if given the choice.
When you’re ready to wean, a gradual approach over several weeks works best for both your body and your child. Start by dropping one nursing session per day and replacing it with a bottle of formula (for babies under 12 months) or a cup of whole cow’s milk or fortified dairy alternative (for children over 12 months). Continue replacing additional sessions over time. Gradual weaning gives your milk supply a chance to adjust and helps your child adapt without abrupt disruption.
Children under 12 months who stop breastfeeding need infant formula as a replacement. Plain cow’s milk is not appropriate before a baby’s first birthday. After 12 months, whole cow’s milk or fortified unsweetened plant-based alternatives can take the place of breast milk as part of a balanced diet that includes a variety of solid foods.