A nursing mother produces about 800-850 ml of milk per day. Human milk gives about 65 kcals per 100ml. this is approximately 500 kcals in 800ml of milk. The metabolic cost of producing milk is about 400kcal. However if she has laid down sufficient stores of fat during pregnancy, she can use them for energy. Thus an extra intake of 550kcals per day would meet her requirements for the first six months and 400 kcal during next six months i.e. 7-12 months more than the usual adult requirements.
Additional calories are required for
Average milk production for a lactating woman is 650ml – 1000ml
Calorie value of human milk is 65 cal / 100 ml.
Calorie value of 650ml is 420 calories Efficiency of conversion of diet calories to milk calories is 60%, 700 calories are required
Metabolic work involved in producing this amount of milk requires around 400 kcal.
The additional energy needed for lactation is drawn from maternal adipose tissue stores laid down during pregnancy. Depending on the adequacy of these stores, additional energy input may be needed in the lactating woman’s daily diet. The output of milk gets reduced after 6 months therefore an additional allowance of 400 cal/ day is recommended.