The number of calories burned by breastfeeding varies depending on the duration of lactation and milk production, but generally:
- During the first 6 months of exclusive breastfeeding, a woman burns approximately 330 to 500 calories extra per day to produce breast milk. Some sources estimate this closer to 500-670 calories daily, roughly equivalent to the calories burned during a 45-minute run
- After 6 months, when infants are partially breastfed and start complementary foods, the extra calories burned drop slightly to about 400 calories per day
- The energy cost is related to the amount of milk produced (around 725 ml/day for exclusive breastfeeding) and the energy content of breast milk (about 65-70 kcal per 100 ml or roughly 20-22 calories per ounce)
- Pumping breast milk burns about the same number of calories as breastfeeding directly, since milk production requires the same energy regardless of feeding method
- If breastfeeding is partial rather than exclusive, calories burned can range from about 250 to 400 calories per day depending on milk volume
In summary, breastfeeding typically burns an extra 330 to 700 calories daily , with exclusive breastfeeding at the higher end of that range, supporting the mother's increased energy needs during lactation
