Feeding Your Baby
Part I: Starting The Baby on Solid Food
Robert P. Lindeman, MD, PhD
Natick Pediatrics, PC

How is feeding a baby like football?
Woody Hayes, who coached the Ohio State Buckeyes for many years, was famous for running the football; He hated the forward pass. Hayes used to say "three things can happen when you throw the ball, and two of them are bad (i.e., there could be an incompletion or an interception).

I think of Hayes every time I visit with a family for a four-month well-child check. Almost without exception, the parents ask me if it’s okay to start feeding the baby solids. I tell them that there are three common reasons why mothers start babies on solids at 4 months, but unlike the forward pass, all three of the reasons are bad, or at least not particularly good. Briefly, only one of the reasons is purely and unequivocally bad; one is understandable though not ideal, and one is a "Quote-unquote" "good reason", which is to say it is a good bad reason. I’ll explain each reason in full below.

The "Bad" Reason
The number one reason why some four-month olds start eating solids is because they can. By four months most infants have such good mastery of their neck muscles that they can keep their heads upright as long as they like. Prior to this, the baby’s head flops to one side, either because of lack of strength or lack of coordination. Obviously, a baby can’t eat who can’t keep her head up in a high chair! In addition, most four-month olds are coordinated enough to move a bit of solid food to the back of their mouth with their tongue and swallow it in a smooth sequence, without choking. We take this simple movement for granted, but it takes a significant degree of coordination that most very young babies do not acquire until four months.

But when it comes to feeding babies, like a lot of things in life, just because you can do something doesn’t mean you should. This is a bad reason to start feeding solids to a four-month old. Here’s why:

Until six months of age, all a normal baby needs to grow and develop is breast milk or formula. The baby is growing rapidly during these months. The baby’s brain is growing especially rapidly – faster than it will ever grow again! Breast milk and formula provide the perfect blend of nutrients that are necessary for normal brain growth during the first six months.

While the baby’s brain is developing quickly, the baby’s digestive system is developing more slowly. The immature digestive system prior to 6 months is often not ready to handle foods that are more complex than breast milk or formula. There is a growing body of evidence to suggest that babies can develop food allergies as a result of early exposure to solid foods.

The Understandable (though not ideal) Reason
The second most common reason for starting solids has to do with sleep. I can usually tell, at the beginning of the four-month visit, which mothers haven’t slept enough recently. Thanks to the Family and Medical Leave Act, by the time their babies are four months old, these mothers have been back on the job for about four weeks. I can recognize the look of chronic sleep deprivation fairly easily now: the skin complexion is ashen, the eyes are sunken, and the feet drag a little as mom struggles with the stroller through the door.

The importance of sleep cannot be overemphasized. Itell parents that sleep is one of the two hinges on which all of pediatrics swings (the other hinge is fluid intake). This rule applies to parents almost as much as it does for the kids. Depending on mom’s sleep requirements and her particular constitution, sleep is more or less important to her health, mental as well as physical. If sleep deprivation is making the mother physically ill, or damaging her sanity, then she cannot take care of her infant!

It is a fact that starting rice cereal at 4 months can occasionally buy 2 or more extra hours of sleep for the mother. This is an understandable reason to start solids, since mother’s health is critical, but it is not an ideal reason, as I explained above.

The "Good" Bad Reason
Prosperity has its negative consequences. One of them has to do with the relative good health of mothers and babies at the dawn of the 21st century. Unlike our great-great-great-great-great grandmothers, mothers today are mostly healthy, well-nourished women. Hundreds of years ago, the typical young mother was not particularly healthy or well fed, and her babies were small and not often healthy in their own right. By contrast, mothers today most often give birth to healthy, hungry, and large babies. And these babies typically stay healthy and grow as fast as is (literally) humanly possible. Human beings were never meant to be so prosperous or grow so fast.

As a result, a problem occurs. Large babies need more calories than small babies. As our large, healthy babies grow, they need more calories. Since the number of calories in breast milk or formula does not change (it is 20 cal/oz), the babies need to drink increasingly large volumes to keep up with their caloric requirements. The mother notices the feeding interval begin to shrink. For example, say the mother had nursed the baby every 3 hours during the day, and every 6 hours at night. At around 4-6 months of age, the baby started to nurse every 1 1/2 hours during the day, and every three hours through the night.

Now the mother has a choice: she can feed the baby so often that, for all practical purposes, she is feeding the baby 24 hours a day. Or she can start feeding the baby solids, and hope that the baby will go back to nursing every 3 hours. Now mother can do something other than nurse the baby, like eat a meal or use the bathroom.

Managing Prosperity: When to Start Solids
At the four month well-child visit, I ask the mother how she is feeding the baby (breast or bottle) and how often. I ask how many hours the baby is sleeping at night. Based on mother’s answers, I can gauge whether the baby has reached the point where he is starting to "outgrow" 20 calorie per ounce breast milk or formula. If it appears that the baby has crossed that threshold, I recommend starting rice cereal. I usually start with one ounce per day. I recommend mixing the rice cereal in breast milk or formula, to a total of about one ounce (this is about one-half the volume of a typical baby food jar) and I recommend feeding this ounce to the baby with a spoon. The best time to feed the baby is at around 7-8 PM, with the hope that the satisfied baby will then nurse and go to sleep. If, after three or four days of this routine, the baby’s feeding pattern hasn’t improved, I often recommend feeding rice cereal twice per day.

I counsel parents that there will be an "adjustment period" when the baby starts rice cereal. The baby may become constipated or may have looser bowels. The baby may spit up more or become more colicky. And almost universally the baby’s bowel movements will start to smell far worse than they ever did when all baby ate was formula or breast milk!

If, at four months, the baby’s feeding pattern hasn’t changed, I don’t recommend starting solids at all. I recommend that parents look out for a shrinking of the number of hours between feedings, and to start the once-a-day rice cereal when the feeding interval or (especially) the hours of sleep consistently cuts in half. Many babies "make it" all the way to six months without starting solids!

At six months of age, a baby begins to require more complex nutrients than can be provided by breast milk or formula. Part two of this series will address feeding your baby between the ages of six and nine months.

For more information about Natick Pediatrics, or to talk to the doctor, please call the office at (508) 655-9699.