process of replacing breastmilk with solid foods in infants

Weaning means changing the diet of a baby from its mother's milk to the food it will eat as an adult. Since only female mammals make milk, weaning is only needed by mammals. When a baby does not drink any more breast milk (or milk substitute), the baby has been weaned.

Human weaning


Babies are able to eat small amounts of solid food, along with breast milk or formula, when they are about six months old. Before this time, a child's digestive system and kidneys are still forming, so the child is not ready for solid food.

Babies do not have teeth and cannot chew their food, so they are usually fed soft, runny food such as cooked mashed fruit or vegetables. Babies cannot digest some foods which adults can eat, including food with nuts or with large amounts of gluten, salt or sugar. Also, babies' digestive systems are very sensitive to bacteria, so they should not eat any foods with honey, eggs or shellfish in them because these foods may contain harmful bacteria.[1]

Weaning conflict


Weaning conflict happens when the mother wants to wean her baby, but the baby wants to keep breastfeeding.[2] The mother tries to force the baby to stop breastfeeding, and the baby tries to force the mother to continue. Some evolutionary scientists think mammal mothers need to wean their babies as soon as possible, so they have a greater chance of having more babies and spreading their genes. But mammal babies want to breastfeed as long as they can so they will have a chance to grow strong, and also to enjoy the full care of their mothers.[2][3] Weaning conflict happens in several mammal species, including primates and canines.[4][5][6]

Indeed, weaning conflict probably always happens, but it does not usually endanger the survival of mother and child. Most mammals have a cut-off system whereby milk cannot be digested after a certain point. Modern humans are very unusual in this respect. They inherit a capacity for permanent digestion of milk.



  1. "Solids: the first steps," NHS Choices website, 29 July 2009.
  2. 2.0 2.1 Salmon, C. & Shackelford, T.K. (2008). Family Relationships: An Evolutionary Perspective. Oxford University Press. pp. 148–149. ISBN 9780195320510.
  3. "Parent-Offspring Conflict in Primates," Archived 2009-04-02 at the Wayback Machine Anthropology 368 course, University of Michigan, April 1997.
  4. Trivers, Robert (2002). Natural selection and social theory. Oxford University Press. pp. 124–126. ISBN 9780195130621.
  5. Cawthon Lang KA. Primate Factsheets: Gorilla Behavior. National Primate Research Center, University of Wisconsin - Madison, 4 October 2005. Accessed 2010 November 16.
  6. Packard, J.M., Mech, L.D. & Ream, R.R. "Weaning in an arctic wolf pack: behavior mechanisms", Archived 2009-10-01 at the Wayback Machine pp. 1269–1275. Retrieved 23 September 2009.