Breastfeeding basics: why do babies seem more full on formula?

Despite efforts by the world's leading medical authorities to educate people about the many benefits of breastfeeding, many women tend to doubt the quality of their breast milk, turning to infant formula to provide for the dietary needs of their babies. Infant formula is, in most cases, not necessary and cannot (given medical research findings) be considered an alternative that is in any way preferable to human milk. One reason that mothers often give up breastfeeding or choose to feed their babies with "supplemental" infant formula may be that certain physiological effects that occur in infants as a result of formula feeding are mistakenly viewed as signs that babies are more satisfied or content than they are while feeding on breast milk alone. Specifically, babies who are fed formula tend to sleep for longer periods after feeding, and tend to demonstrate hunger cues less frequently than exclusively breastfed babies do.  

 

While it is very true that babies who are breastfed exclusively need to feed more often (especially in the first few months) than their formula-fed counterparts, this does not mean that formula provides better comfort or nutrition. Breast milk is made of specialized fats, proteins, and carbohydrate complexes that are easy for a baby's digestive system to "break down" and process. As a result of the high digestibility of breast milk, babies are able to digest and absorb nutrients of breast milk more easily than they can infant formula, which does not contain this special complex of nutrients. Because babies digest breast milk quickly and efficiently, they are able to feed more often than babies who are fed formula that is harder to digest. It is because of this vast difference in digestibility between breast milk and formula that such different feeding recommendations apply between the two options. For example, pediatricians suggest that breastfed babies be fed on-demand (whenever they are hungry), whereas babies who are fed formula need to adhere to more regularly scheduled feedings, lest the baby become over-fed and suffer digestive problems. 

 

Babies sleep more soundly after being fed formula for the same reason that adults become sleepy after over-indulging on rich, carbohydrate-filled foods. A part of the autonomic nervous system, the parasympathetic nervous system, activates to aid digestion. The parasympathetic nervous system induces the body into rest to ensure that its available supply of energy is directed toward the process of digestion, which is essential for the body to metabolize nutrients so that it can replenish that energy. This is sometimes referred to in casual, non-medical terms as a "food coma", although it is most certainly not a coma, per se. This effect is most noticeable if a person has ingested foods that are difficult to digest (such as heavy fats, complex carbohydrates, or large proteins).  

 

Babies who sleep more heavily after being fed formula are simply experiencing a reaction to a food source that is suboptimal in its digestibility, which is a direct contradiction to the widely-held belief that they are sleeping because they are "better fed". Just as adults experience indigestion, gas, bloating, or constipation from eating too much (or eating foods that are very rich), so can a baby experience these problems from formula feeding. Breastfed babies can also experience problems with digestion, but are far less likely to have these issues than babies who are fed infant formula. A baby is less likely to seek more milk if they feel full due to slowed digestion, so while babies may seem less hungry on formula than breast milk, it does not mean that they are receiving more thorough nutrition by way of formula. Rather, they may actually be over-fed.  

 

A baby's constant cycle of feeling over-full on formula may be the basis for a lower obesity risk in breastfed infants, based simply on the fact that formula-fed babies are being conditioned to understand that "over-full" equates to "hunger satisfaction". Just as in adults who eat nothing but rich foods in large quantities at less frequent intervals, a baby's metabolism can slow to a less effective rate, potentially leading to excess weight. Breastfed babies are naturally a little bit leaner during their first six months of life than formula fed babies, namely because of fast metabolism and smaller, more frequent meals.

 

When viewing these feeding differences as a matter of healthy metabolic rates, it should become easier for mothers to understand the needs of their breastfeeding infant. Most health-conscious adults are at least aware of the fact that it is healthier for them to eat smaller, more frequent meals than large and less frequent ones. Because of the differences in average weight gain between formula and breast fed babies, it is of the utmost importance that breastfeeding mothers trust their child's care to a breastfeeding-friendly pediatrician, who will be evaluating the baby's growth using charts that are appropriate for breastfeeding babies. 

 

Very recent research indicates that breastfed babies who seem harder to soothe and who cry more frequently are not, in fact, showing signs of stress. An article in Medical News Today's pediatric category suggests that these signs of irritability are a natural part of communication between mothers and babies, and that it should not discourage mothers from breastfeeding. The article goes on to suggest what many lactation consultants and breastfeeding proponents have argued for years, which is that parents tend to have less-than-realistic expectations of normal newborn behavior. While babies are simply small people, they are also undeveloped human beings that require care and bonding to grow into well-developed people. It is a learning process that must begin with simple elements of socialization, such as physical contact, eye contact, and closeness to mothers. Breastfeeding provides babies a closeness and exclusivity of contact with their mothers that cannot be entirely replicated by any artificial means. 

 

Although breastfeeding can be a challenge at times for new mothers, it may be helpful to remember that infancy and toddlerhood (should a woman choose to extend breastfeeding beyond a year) are very brief periods in a child's life. During this short amount of time, breastfeeding can provide health and developmental benefits to mothers and to their babies that extend beyond childhood and into adulthood. Choosing to breastfeed may indeed be one of the best investments a mother can make into their child's lifelong wellbeing.