Final answer:
It is generally true that exclusive breastfeeding can help mothers lose more weight postpartum due to increased metabolic demands and uterine contractions. The composition of breast milk changes from colostrum to transitional milk, and finally to mature milk to cater to the infant's nutritional needs.
Step-by-step explanation:
The statement that mothers who exclusively breastfeed lose more weight in the first 6 months post-partum is considered to be generally true. Breastfeeding can induce a substantial metabolic increase in the postpartum person, which helps in consuming the fat reserves stored during pregnancy.
Lactation, or the process by which milk is synthesized and secreted from the mammary glands in response to an infant suckling at the nipple, also promotes uterine contractions, aiding the uterus in returning to its pre-pregnancy size. This process, combined with the energy required to produce breast milk, may contribute to weight loss during the postpartum period.
As for the composition of breast milk, it changes considerably during lactation. In the first few days after childbirth, a mother secretes colostrum, a thick and nutrient-rich substance. This is followed by transitional milk after about the third postpartum day, and then by mature milk from approximately postpartum day 10. These shifts in milk composition are designed to meet the evolving nutritional requirements of the growing infant.