What is overfeeding?
Overfeeding, also called over-nutrition, refers to a baby receiving more food than his stomach can hold and/or more nutrients than his intestinal tract is able to digest.
A baby could receive excess nutrients from large volume feeds or an accumulative effect of small volume feeds. Overfeeding can occur if baby receives regular strength infant formula or breast milk, or high-energy feeds.
A baby might overfeed due to circumstances that affect his ability to self-regulate his milk intake (decide for himself how much to eat). Or, he could be overfed as a result of being pressured to consume more milk than he needs.
Who is at risk?
Newborn babies (birth to 3 months of age) are vulnerable to overfeeding due to developmental limitations that affect their ability to control their milk intake.
Bottle-fed babies are at increased risk of overfeeding because it’s harder for a baby to control the flow of milk and easier to pressure a baby to feed from a bottle compared to breastfeeding.
Why babies overfeed
Overfeeding typically occurs due to a combination of the following reasons:
- Mistaking hunger cues
Hunger is one of the first things blamed when a baby cries, has broken sleep, and when he indicates he wants to suck. A newborn baby crying or wanting to suck does not provided proof of hunger. Babies cry for many reasons, most of which have nothing to do with hunger. Babies are in an oral stage of development and gain comfort from sucking. Most babies enjoy sucking when they’re hungry, tired, bored, uncomfortable, upset, and for pleasure.
If a baby’s behavioral cues are misread, it means he’s going to be offered feeds at times when he’s not hungry.
- Active sucking reflex
Babies under the age of 3 months have an active sucking reflex. The sucking reflex is triggered by pressure on baby’s tongue and roof of his mouth by the nipple of a feeding bottle, his mother’s nipple, a pacifier, his fist or fingers, or a parent’s finger. A reflex is an automatic, involuntary action. When a baby’s sucking reflex is triggered he will suck because it is an involuntary reaction.
An active sucking reflex means a newborn has limited ability to control the flow of milk from a bottle or stop when he has had enough. He may appear to hungrily guzzle down the milk, but will do so regardless of whether he’s hungry or not.
- Feeding too quickly
It takes time for our brain to register the sensation of satisfaction that occurs after eating a meal in both adults and babies. The faster a newborn feeds the greater the risk he may overfeed.
The nipple speed (determined by the size of the hole) and baby’s sucking ability influence how quickly milk flows from through the nipple. Babies vary considerably in their strength and sucking ability. Just because a nipple is designed for babies of a specific age group doesn’t guarantee that it’s a suitable speed for an individual baby. (See How long should a bottle-feed take.)
- Overlooking or ignoring satiety cues
Satiety means a baby’s hunger is satisfied. When a baby has had enough to eat he will stop sucking. If he’s over the age of 3 months, he might also push the nipple out with his tongue, clamp his lips together, turn his head away, arch back or push the bottle away.
A caregiver might overlook or ignore baby’s cues of satiety in an attempt to encourage him to drink a pre-determined volume of milk. It’s not difficult to make a baby eat more than he wants while his sucking reflex is active.
- Overestimation of milk requirements
Calculations used by health professionals to estimate babies’ milk needs are based on averages. Such figures do not take into account the many reasons why an individual baby might require less milk than average. (See How much milk does baby need for reasons.)
Overestimation of a baby’s milk requirements will not cause overfeeding unless the parent tries to make baby drink the overestimated amount, which is a natural response when a parent has been led to believe their baby needs that amount. Parents are often told or may get the impression that the estimated amount is a ‘should have’ or ‘must have’ target. As a result many parents overlook or ignore their baby’s satiety cues and try to make their baby consume the recommended amount.
Parents of preterm babies are often taught to believe they must control how much their baby eats. Something they may have needed to do when their baby was very young and weak, but not forever. They need to allow baby to decide how much his body needs by the time he is 8 weeks adjusted age or younger. They’re not the only parents who believe they need to make sure their bottle-fed baby eats ‘enough’ (usually an amount decided by others and not baby). This is a flawed belief when you consider that breastfed babies don’t need others to decide how much they ‘should’ or ‘must’ eat.
- High-energy milk
High-energy milk means it contains more calories in less volume compared to normal strength infant formula or breast milk, which provides 20 kCal per ounce. Nutrients and calories might be increased as a result of adding extra scoops of formula, a milk fortifier, oils, carbohydrates, rice cereal or oatmeal. Or it could be a commercially produced high-energy formula, which range from 22 to 30 kCal per ounce.
Providing high-energy feeds makes it easier for weak or sick babies to get the calories they need with less effort. However, high-energy feeds also make it easier for a healthy newborn to overfeed or be overfed.
- Parent’s opinion of a ‘healthy’ baby
Many parents and cultures consider chubbiness in infancy to be a sign of good health. A parent might try to pressure their baby to drink more than he’s willing to drink in order to ‘fatten him up’, or make him grow faster or bigger. Small babies and lean babies are at greater risk of being pressured to eat compared to others. However, chubby, overweight babies are at increased risk of having their milk needs overestimated using standard calculations that estimate milk requirements based solely on age and weight.
- Broken sleep
Feeding and sleeping are closely linked. A baby’s sleeping pattern will influence his feeding pattern. Short naps usually mean short intervals between feeds.
Broken sleep means baby wakes before his sleep needs are met. If he wakes too soon, it won’t be long before he becomes irritable due to tiredness. Baby’s tired cues, which involve fussing, crying and desire to suck, are commonly mistaken as hunger.
A major reason for babies to experience broken sleep is because they often learn to rely on negative sleep associations as a way to fall asleep. Because parents in general are unaware of the effects of sleep associations on their baby’s ability to sleep, some assume baby is waking because of hunger. And as a result, they overlook or ignore their baby’s satiety cues while trying to make him drink larger volumes. Others add cereal to their baby’s milk mistakenly believing more nutrients will make him sleep longer.
- Feeding-sleep association
If a baby regularly falls asleep while feeding, feeding can become a sleep association. When a baby has learned to rely on feeding as a way to fall asleep he will appear hungry whenever he’s tired and ready to sleep. He may also want to feed as a way to return to sleep if his sleep is broken.
A feeding-sleep association makes it difficult for a parent to tell the difference between baby’s hunger and tiredness cues.
How a baby’s body responds to overfeeding
While the nutrients consumed as a result of overfeeding exceed the amount a baby needs for normal growth this won’t automatically cause large weight gains.
Our bodies have thousands of homeostatic mechanisms that automatically act to maintain an internal state of balance or harmony. These compensate or minimize the effects of overfeeding in multiple ways. Two examples include:
- When baby drinks too much
A baby’s stomach will expand as he eats and contract as food slowly empties into his intestinal tract. However, there are limits on how far it can stretch. If stretch receptors in the lining of baby’s stomach stretch beyond a normal range, he will regurgitate (reflux) his stomach contents – ranging from small spit ups to large projectile vomits – during or shortly after the feed has ended
If an overfed baby regurgitates large amounts of milk he may be spared from the effects of over-nutrition. If not, excess nutrients will pass into this intestinal tract where other homeostatic mechanisms take action.
- When over-nutrition occurs
A baby’s immature digestive system has a limited ability to produce digestive enzymes within a specific time period. A healthy baby can digest enough nutrients for healthy growth but his intestinal tract might not be able to digest an excessof nutrients. If nutrients are not digested (broken down by digestive enzymes) they cannot be absorbed into his blood stream, and therefore the energy (calories) from undigested nutrients is not stored as body fat. Instead undigested nutrients pass through his intestinal tract and are pooped out.
Symptoms linked to overfeeding
In the case of overfeeding, you might observe your baby display the following signs and symptoms:
- milk regurgition due to hyper-extension of baby’s stomach;
- belching due to swallowing large amounts of air while speed-feeding.
- frequent sloppy, foul smelling bowel motions if baby is formula-fed, or watery, explosive bowel motions if baby receives breast milk;
- extreme flatulence;
- intestinal spasms or cramps (baby often fusses, cries or grunts while bearing down like he’s trying to poop).
These intestinal symptoms occur as a result of fermentation of undigested lactose in baby’s large intestine.
- sleep disturbance.
When a baby’s stomach is stretched beyond a normal range and/or when his intestinal tract is churning in an attempt to deal with an excess consumption of nutrients, is it any wonder that he would be irritable and have trouble sleeping.
These signs and symptoms primarily relate to baby’s homeostatic mechanisms doing exactly what they’re designed to do – correct the imbalance between what baby needs and what he receives. While the actions of homeostatic mechanisms can cause a baby varying degrees of physical discomfort, they protect him from greater harm that would occur from an excessive accumulation of body fat.
A baby’s current weight or weekly weight gain is not a good indicator of overfeeding. An overfed baby could be underweight, overweight or within a normal weight range.
Homeostatic mechanisms explain why an overfed baby doesn’t necessarily gain large amounts of weight. A baby could overfeed and his weight gains consistently remain within a normal range.
Some babies are naturally inclined to accumulate body fat more readily than others. Others may gain large amounts of weight because their homeostatic mechanisms are unnaturally prevented from working by certain medications and dietary changes (explained below). As a result some overfed babies lay down large stores of body fat which cause them to become overweight or obese. However, an overweight or obese baby is not necessarily overfeeding or overfed at the present time. He might have gained large stores of fat in the womb or as a result of previous overfeeding. So it can’t be assumed a baby is currently overfed simply because he’s overweight.
An overfed baby could display slow or poor growth as a result of extreme milk regurgitation or vomiting. When an overfed baby throws up, the amount won’t necessarily be limited to the excess. Once reflux or vomiting mechanisms are triggered, he could all but empty his stomach. In some cases where babies overfeed, less is more. Less milk -> less vomiting -> better growth.
A baby could overfeed and yet gain less than expected weight in the case of catch-down growth – a normal variation of growth that is often mistaken as poor growth.
How to prevent overfeeding
The goal is to support your baby to self-regulate his milk intake. You can achieve this in the following ways:
- Check that your expectations of your baby’s milk requirements are realistic. See How much milk does a baby needs.
- Check that your baby is not feeding too quickly. See How long should a bottle-feed take. If necessary slow down feeds by switching to a slower nipple.
- Follow a semi-demand feeding pattern to minimize the risk of misinterpreting his hunger cues. (See feeding patterns for bottle-fed babies.)
- Learn to recognize your baby’s cues that indicate he has had enough. Don’t try to make him drink more than he’s willing to drink. Never pressure your baby to feed.
- Check that your baby is getting enough sleep. See How much sleep do babies need? If he’s not getting close to average sleep for age, then find out if this could be due to a sleep association. See my book ‘Your Sleepless Baby’ for strategies on how to promote healthy sleep habits.
- Discourage a feeding-sleep association by preventing your baby from falling asleep while feeding.
- Satisfy your baby’s desire to suck using means other than feeding. Offer him a pacifier or your finger for him to suck on. If he’s hungry, he will let you know. He won’t be content to suck on a pacifier or your finger.
- Don’t assume he’s hungry every time he fusses, cries or wants to suck. If its too early for a feed try other soothing methods first, but feed if they aren’t working.
Don’t restrict your baby’s milk intake. Dietary restriction is a band-aid solution because it doesn’t address the underlying reasons for overfeeding to occur. It’s not your role to decide how much your baby should drink. That’s his job. Your job as your baby’s caregiver is to remove any barriers (such as those described in ‘Why babies overfeed’ section) which might cause him to overfeed.
Gastro-intestinal symptoms associated with overfeeding are often misdiagnosed as colic, reflux, milk protein allergy or intolerance, lactose intolerance or gastroparesis (delayed gastric emptying).
Reasons for misdiagnosis include:
- The possibility of overfeeding is notconsidered unless baby is overweight or gaining excessive amounts of weight. Even then, overfeeding can be overlooked as a cause of a baby’s gastro-intestinal symptoms.
- Parents are not asked about their baby’s milk intake, feeding and sleeping patterns, or their infant feeding and settling practices. So the common reasons for overfeeding described under ‘Why babies overfeed’ are not assessed and therefore not addressed.
- Medical doctors are nottrained to advise parents on behavioral strategies to prevent overfeeding. They’re trained to diagnose medical conditions based on symptoms; so that’s what they do.
In the absence of knowledge regarding behavioral causes for healthy babies to display gastro-intestinal symptoms (described in this article) assumptions are made and misdiagnoses occur. As a result, parents don’t receive effective advice on how to adjust their infant feeding practices to prevent overfeeding; instead baby receives medical treatment.
Medical treatments do not cure conditions such as colic, reflux, milk allergy or intolerance, or gastroparesis (or problems such as overfeeding). The purpose of treatment is to relieve the symptoms associated with these conditions, i.e. reduce milk regurgitation; neutralize acid reflux; minimize intestinal gas; relieve discomfort due to intestinal spasms, normalize bowel motions and alleviate discomfort assumed to occur as a result of these conditions.
DIAGNOSIS 1: Colic
Colic is often, but not always, the first problem blamed for an overfed baby’s distress and intestinal symptoms.
Medications to treat colic:-
- Colic remedies containing symethiconecan help a baby burp up swallowed air that occurs while feeding, but has no effect on other symptoms associated with overfeeding. Other over-the-counter colic mixtures have minimal or no effect on overfeeding symptoms.
- Antispasmodic medicationssuch as dicyclomine and hyscyamine can relieve intestinal spasms associated with over-nutrition.
- Antihistamineslike diphenhydramine have a mildly sedative effect that may reduce baby’s irritability.
Antispasmodics or antihistamines require a doctor’s prescription because they can have serious side effects. (See Colic medications for more.)
DIAGNOSIS 2: Reflux
An overfed baby might be diagnosed with reflux (gastro-esophageal reflux disease or GERD) if he regurgitates milk or ‘silent reflux’ if he doesn’t. Either way it’s assumed his distress is due to burning effects of regurgitated acidic stomach contents.
Medications to treat acid reflux:-
- Acid suppressing medications such as ranitidine, omeprazole or lansoprazole, might have a small effect on symptoms associated with overfeeding. Because lack of stomach acid hinders the breakdown of proteins in the stomach, these meds can slow down gastric emptying time (the time it takes for milk to empty from the stomach). This means nutrients empties into the intestinal tract slowly and as a result may reduceintestinal symptoms associated with over-nutrition. (More time enables more nutrients to be digested.) (See Antacid medications for more.)
DIAGNOSIS 3: Milk allergy or intolerance
If medications make no noticeable difference to baby’s symptoms, milk allergy or intolerance might be the next diagnosis he receives.
Dietary change to treat milk protein allergy or intolerance:-
- Lactose-fee formulas, which includes cows’ milk based formula with lactose removed, soy infant formulas and hypoallergenic formulas, can relieve intestinal symptoms because an absence of lactose eliminates the possibility of lactose overload symptoms occurring in baby’s large intestine.
- Lactose-reduced formulas, for example anti-colic and AR formulas, can reduceintestinal symptoms by reducing lactose overload symptoms.
- Food thickenersadded to a baby’s milk or already in AR formulas can reduce milk regurgitation. Because they slow down gastric emptying time and intestinal motility (the speed which food and waste travels through the intestinal tract) they can reduce intestinal symptoms linked to over-nutrition.
- High-energy feeds can reduce milk regurgitation but may increase intestinal symptoms due to over-nutrition.
- Maternal dietary restrictions. Breastfeeding mothers may be advised to eliminate dairy and other specific foods from their diet. This will have no effecton the symptoms caused by overfeeding.
DIAGNOSIS 4: Gastroparesis
If acid suppressing medications and dietary changes fail to make a difference, baby might then be diagnosed with gastroparesis.
Medications to treat gastroparesis:-
- Prokinetics medications,such as domperidone and erythromycin (which is also an antibiotic), speed up gastric and intestinal motility. In the case of overfeeding, these can reduce milk regurgitation but may increase intestinal symptoms.
Medications and dietary change have varying effects on gastro-intestinal symptoms that occur in response to overfeeding and over-nutrition. Some have no effect. Others reduce some symptoms but increase others. The reason these treatments reduce or increase gastro-intestinal symptoms is because they hinder or enhance the actions of a baby’s homeostatic mechanisms.
Even when medications appear to help, symptoms will return once the effect wears off. While a baby receives medications he’s exposed to the potential of unwanted side effects directly linked to the medications or indirectly linked as a result of inhibiting or enhancing the actions of his homeostatic mechanisms. (See Colic medications and Antacid medications for more.)
None of these treatments address the underlying cause of symptoms. Failure to address the cause can result in multiple diagnoses, multiple medications and dietary changes.
Fix the problem and not the symptoms! Prevention of overfeeding trumps medical treatments that mask the symptoms.