A Short History
Have you ever wondered why it seems like breastfeeding was more successful and came more naturally to women hundreds of years ago compared to our current generation? The answer may boil down to feeding patterns. Historian Jacqueline H. Wolf studied the history of breastfeeding in the US to learn about when breastfeeding stopped being the norm and successful breastfeeding became the exception. She says,

"This goes back to how I ended up looking at the 1880s and the 1890s as a turning point. The U.S. was rapidly urbanizing and industrializing, and that changed everything for American culture. People were starting to work in factories and they had to pay more attention to time. We see the introduction in infant-care manuals of very detailed feeding schedules. The theory was that adults were having a hard time with scheduling, but if you can adapt a baby to scheduling, they wouldn’t have that tough time. The reason that’s really interesting is that anyone who knows anything about breastfeeding works knows that the more a baby sucks, that’s what stimulates milk production. If you put a baby on a strict schedule, mothers’ milk supplies go down. So you see mothers beginning to complain that they didn’t have enough milk and it was then that the medicalization began, because doctors became involved in what seemed to be a very serious problem of lactation failure. No one connected it to the change in culture and the change in infant feeding habits."

Many of our assumptions about feeding patterns for babies originates from 150 years of living clock-bound lives and several decades of bottle-feeding as the norm. What we have come to assume is "normal" for an older baby is not necessarily normal from an evolutionary or biological perspective. Most infant schedules developed in the past 150 years were designed to get babies to accept bigger, less frequent feedings. Prior to this time most people did not even have access to clocks and followed a very flexible rhythm to their day. Not only have our cultural practices led to wide scale lactation failure, but studies have also found the obesity epidemic has roots in a child's first year of life.1 While office buildings may have replaced factories, many of the effects of the industrial revolution are here to stay. None of us are prepared to toss our clocks out the window and live bohemian freestyle lives (though its tempting!). With that in mind, let's take a look at normal feeding patterns from a biological perspective and then consider how we might incorporate this knowledge into our busy lifestyles.
Studies Documenting Average Breastmilk Intake
Studies done on healthy, full term breastfeeding babies show that babies intake peaks within the first month and plateaus at 25-30 oz per day.2, 3, 4 Surprisingly, after the first month babies do not need more milk as they get older. The first 3 months their metabolism is very high (due to rapid growth) and they need a disproportionately high amount of milk for their size.4 Later in the year their metabolism slows (as growth slows) so despite being bigger their milk intake needs are the same until solid foods start to replace milk.4 What tends to change over time is their feeding patterns - how that 25-30 oz gets divided up between feedings. Breastfed babies will only have small changes to their feeding patterns over time.4 They might space out night feedings while continuing to nurse frequently in the daytime. This is partly because mothers have limited breast storage capacity. Breast storage capacity is how much breastmilk a woman can comfortably store in her breasts between feedings before her body interprets the fullness as a signal to decrease milk production. Its determined by the number of milk glands in a mother's breast and can range widely from woman to woman.4 In my experience the average woman can maintain around 3-4 oz combined in her breasts but a few rare women can fit as much as 10 oz combined. Simple math will tell us that 28 oz (daily total) divided by 3.5 oz (average storage capacity) = about 8 feedings per day. If the average mother nurses or pumps less often than this her body will signal to decrease milk production and baby's intake will drop.

Weighing Babies Before & After Breastfeeds 
As a lactation consultant in private practice, I get to work with babies of all ages. I've weighed over a thousand babies young and old before and after feeding to calculate their intake. One of the interesting phenomenons I've observed is that even when mothers have an unusually high milk storage capacity - for example, being able to pump 8 oz at a time - their babies don't take that much directly from breast. The older babies I've weighed before and after feedings whose mothers have a great milk supply usually take 3-4 oz per feeding...only a handful of times have I seen babies take up to 5 oz. They average about 8 feedings per 24 hours with a normal range of 6-10. This same finding has been confirmed in several studies where babies of all ages were weighed before and after feeds for 24 hours.4 One of the most common reasons that women experience late-onset low milk supply or baby's growth slows is due to baby not breastfeeding often enough. People tend to assume that an older baby is taking bigger feeds which leads to offering the breast less often or letting baby sleep through the night prematurely. Its just not how nature works. If you are struggling with late onset low milk supply or a baby who is not growing well, the first thing to check is whether baby's feeding patterns are actually normal from a biological perspective. Other signs that something might be off are a baby who is up very frequently at night (possibly not eating enough in the day) or a pumping mother that can't keep up with her baby's bottle intake.

Studies Documenting Risks of Large Volume Feeds 
As the evidence accumulates for older breastfed babies sticking with 3-5oz feedings at breast, we start to realize this is the biological norm. Its not surprising then that studies have found there are health risks when babies develop feeding habits that are not biologically normal. One such study found that when babies are given bottles over 5 oz they are at higher risk of obesity.5 This is true whether it is breastmilk or formula in the bottle.6 The theory is that babies don't regulate their intake on bottles the same way they do at the breast, making it easier to stretch baby's stomach capacity.7 At the breast, only a hungry, strong suck transfers milk. On a bottle, any suck - even a light comfort suck - will cause milk to flow. As a result, bottle-fed babies tend to continue eating even after they reach satiety. This is even more so the case if caregivers are encouraging a baby to take bigger, less frequent feedings.7 We end up with a culture that expects older babies to drink 8 oz bottles, babies stomachs stretch...and then we wonder why our older children overeat.
Responsive Feeding for Modern Lifestyles 
In non-industrialized cultures, mothers often carry babies in a wrap all day and offer frequent - even hourly - breastfeeds.8,9 At night, these cultures co-sleep and have the breast available to baby throughout the night. In our fast paced, clock-bound society this often isn't possible or appealing. Instead, I recommend a balanced approach that combines responsive feeding with a biologically informed routine. This means that mothers offer the breast (or caregivers offer a bottle) at specific times in a baby's daily routine in addition to feeding responsively anytime baby "asks." Older babies might request breastfeeding by bobbing against or pushing on mother's chest or by fussing. However, I find that when mothers are offering frequently baby is very content and doesn't have much need to ask for the breast other than occasionally for comfort. It gives you the chance to confidently plan activities in your day's routine and gives baby prediciability that often leads to improved sleep

Below is a daily schedule that includes mother-led feedings when baby wakes up in the morning, before and after naps, and at bedtime. Most babies also wake once or twice a night to nurse until they are skilled at eating from all food groups. (Early night weaning leads to low milk supply unless mother pumps at night.) If you are looking for structure to your day, my suggestion is to build a routine that centers around nursing upon waking, before and after naps, and at bedtime. As an added benefit, breastfeeding before naps helps baby sleep better thanks to the sleep inducing hormones in breastmilk such as melatonin. This feeding routine also keeps baby from waking up early due to hunger. (If you need help troubleshooting sleep issues, see my article series on infant sleep.) The exact times are less important and can be adjusted based on you and your baby's needs. 


If your baby is bottle-fed, you can still use the schedule above. Or you can build your own schedule using one of the two sample feeding patterns below.  The guidelines below are typically more helpful for bottle-fed babies. You'll notice that the quantity of breastmilk decreases with age as solid foods play an increasing role in baby's diet.  Keep in mind if you are breastfeeding its not possible to nurse "too often" or "too much." Babies won't overfeed at the breast. All you are doing is offering and responding, not forcing. So don't be afraid to nurse often. For more tips on healthy bottlefeeding, see Bottlefeeding the Breastfed Baby.


The Best of Both Worlds
Combining responsive feeding (nursing anytime your baby wants) with offering scheduled feedings (a routine based on biological norms) is possible and may be the solution modern families need to make breastfeeding successful in the midst of a structured lifestyle. If you need help figuring out the best routine for your milk production, your lifestyle, or your baby's needs please feel free to make an appointment. I am happy to help!






References
Breast milk volume and composition during late lactationJ Pediatr Gastroenterol Nutr., 1984
Why African Babies Don't Cry, accessed 08/2018