Breast milk / formula question

[Meggie]

I am wondering if anyone knows the comparison between breast milk and formula.  For instance is one ounce of formula the same equivalent as one ounce of breastmilk calorie-wise?  I am formula feeding my LO with one bottle of breast milk a day and she seems to be taking less of the breast milk at a feeding as she does the formula.  I am also counting the ounces thta shes getting in a day and am wondering if my count is wrong due to (possible) a baby's need to take less breast milk to feel full and get her calories than formula.

[Samuel's mum]

Your hunch is spot on.

As a rough guide breastmilk has 22 calories per oz while formula has 20 calories per oz. However this is an average for breastmilk because at certain times of day the fat content could be more or less.
Breastmilk has a average of 1.2 g of fat per oz and formula contains 1.06g.

However what is more significant is that breastmilk is absorbed very efficiently by the body - this is why a healthy breastfed baby can go a week or more without pooing and this isn't considered a problem, there's just very little waste.

All this means that YES you will expect your baby to take less breastmilk in comparison to formula.

The Pocket Guide to Breastfeeding and Human Lactation (Riordan and Averbach) [a guide used by doctors and health professionals] says:

Average infant breastmilk intake:

Birth to 24 hrs: quarter oz
24hrs-2 weeks: 1 - 1.5 oz
2 weeks - 1 month: 1-3 oz
1-2 months: 2-3 oz
2-4 months: 3-4 oz
4-6 months: 4-5 (It stops there).

So less than formula quantities for those ages.

HTH

[Meggie]

Thanks for the info! That is SO helpful.