The interesting thing is that the baby controls the mother's milk volume
AND the fat content
of the milk - if allowed.
The more the breast is emptied, the more milk is made. That is why the same woman can nurse twins one time and a singleton baby another time without under or over supply issues.
The more empty (this is a relative term as it is never really empty) the breast the faster the new milk is made.
The more empty the breast, the higher the fat content of the milk that is left.
If the baby is fed on its request instead of by a schedule the mother will make the correct volume and fat content of milk.
Some popular parenting "philosophies" praise schedules for babies. This is not physiologic but may "work" for some mothers. This occasional "success" perpetuates the myth that this scheduling can work for most cases.
The storage capacity of the breast varies from mother to mother. If Mother "A" can store 4 hours worth of milk and she puts her baby on a 3 hour schedule the baby may do OK; at least as far as weight gain goes. BUT, if Mother "B" can only store 2 hours worth of milk and she puts her baby on a 3 hour schedule, well....something has to give. Maybe supplementation with formula followed by premature weaning takes place but failure to thrive may also occur if mother persists in scheduled and un supplemented breastfeeding. If Mother "B" would just feed her baby on its request instead of some silly schedule, baby would feed more often and Mum would make enough milk over 24 hours for baby to thrive.
An amazing new fact revealed by the wonderful research of Peter Hartman and friends over the last 5 years or so is that the volume of milk an exclusively breastfed and thriving 6 week old baby takes is very close to the volume of milk the same baby will take as an exclusively breastfed and thriving 5 month old. The older baby is usually twice the weight of the his younger self and still growing well on this lower volume. Why does this work??? We don't know but since BREASTFEEDING IS NORMAL and is the model upon which all infant feeding should be based we can just be interested in this intriguing fact until the rest of the research filters in.
Pity the poor formula fed baby with his unvarying and yucky diet, needed in larger and larger amounts until he finally gets a taste of something different.
The formula industry changes the recipe for the formula constantly. But do they tell the parents of this year's toddlers that last year's formula was so defective that it needed to be redesigned, again?? Of course not.
Breastmilk also changes constantly but in an appropriate way. It varies according to the time of day, the age of the baby, the length of the gestation, the length of the feeding and the time since the last feeding. Flavors even vary according to the foods the mother eats. This is how the infant becomes familiar with his native food instead of the dictates of large commercial interests.