Infant Formula

Created: December 12, 2014. - Reviewed: April 15, 2015.
Infant Formula
Rowena Bennett

Rowena Bennett

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Specialise in infant sleeping problems, feeding aversion and tube weaning. 


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Why an infant formula?

If you have decided not to breastfeed your baby, then the next best thing is to provide an infant formula. The milk in the majority of infant formulas are based on cows milk, goats milk or soy beans, which has been modified or changed with important nutrients added so that the formula is similar to breast milk in nutrient composition. (It's not a perfect match because the exact chemical make-up of breast milk is unknown.)

Many different types of milk (other than an infant formula) have been given to babies in the past, but we now know that a lot of these are not suitable for babies and can cause serious health problems.

About infant formula

Infant formula comes in 3 different ways:

  • ready-to-use (which is the most expensive)
  • concentrated liquid
  • powder (which is the cheapest) 

When prepared for feeding, according to manufacturer's recommendations, these different forms of infant formula are equivalent in nutritional content.

There are two categories of formula - 'Starter' formulas are designed for babies 0 - 6 months and 'Follow-on' formula can be offered to babies older than 6 months.

Apart from the large variety of different brands of infant formulas, found on your supermarket shelves, these is also a range of specialty formulas available for babies with problems associated with prematurity, lactose intolerance, milk allergy, reflux and other more serious conditions.

With the exception of some of the specialty formulas, all infant formulas are made up to provide the same amount of energy (calories) per ounce. As your baby grows she needs more milk, not stronger milk.

There is very little difference between the different brands. When choosing a formula for your baby, the most expensive is not necessarily the best . Regulations on the manufacture of infant formula are very strict in most countries, which means the different brands of formulas are generally very similar in nutritional content. As prices can vary from store to store it pays to shop around.

Specialty formula

There are a number of different types and brands of specialty formulas on the market, such as those for premature infants or infants with heart disease, malabsorption disorders, an inability to digest fats or other conditions.  Specialty hypo-allergenic formulas are available for babies with Cows Milk Protein Allergy (CMPA) or Milk, Soy Protein Intolerance (MSPI). In most countries these specialty formulas require a doctor's prescription.

Low-lactose or lactose-free formula

Children can sometimes develop a secondary lactose intolerance following a gastro-intestinal infection, when the ability to digest and absorb lactose is lost temporarily. A low-lactose or lactose-free infant formula is often recommended for a few weeks, after which time the child can usually return to his/her regular formula.

Low-iron formula

Infant formulas currently available in the US are either 'iron-fortified' with approximately 12 milligrams of iron per liter or 'low iron' with approximately 2 milligrams of iron per liter.

Iron is essential for growing babies . For the average baby a low-iron formula is a nutritionally inadequate formula. Unfortunately, these formulas are sometimes used for healthy babies experiencing problems with constipation. Infant constipation is rarely due to an excess in iron.

CAUTION: Although low iron formulas can be purchased over-the-counter in many countries it should ONLY be used on medical advice.

AR (Anti Regurgitation) formula

AR formulas are thickened with carob bean gum or starch, such as rice or cornstarch. Each formula manufacturer may use a different substance to thicken the milk. One brand of AR formula may work better than another for some babies.

AR formulas are designed to help to reduce spitting-up and regurgitation associated with gastro-esophageal reflux. However, thickened formulas do NOT always help. Some babies will fuss more with thickened formula or may become constipated or spit-up even more.

AR formulas are modified by removing some of the lactose (sugar in milk) to adjust for the extra calories provided by the thickening agents. As a result, the amount of calories in an AR formula remains the same as regular formula (which is not the case when you use a food thickener to thicken formula).

A certain amount of regurgitation or reflux (spitting-up) is normal for healthy babies. If your baby is not distressed by regurgitation or minor spit-ups, it's not essential to use a thickened formula at all. In a healthy, thriving baby minor spit-ups are more of a laundry problem than a health concern. (For severe vomiting consult your baby's doctor.)

Note: AR or thickened formulas are NOT recommended for healthy infants who DON'T spit-up or regurgitate milk.

Partially hydrolyzed formula

If a formula fed baby is at risk of developing an allergy, e.g. if either parent or a brother or sister have an allergic condition (such as eczema, asthma or a food allergy) using a partially hydrolyzed formula may help to reduce the risk of a milk allergy developing. Although soy formula was recommended for this purpose in the past, studies have shown soy formula does not reduce the risk of allergies to any great extent.

Partially hydrolyzed formulas are based on cows milk, but the protein molecules in these formulas have been partially broken down into smaller molecules that should be less likely to cause allergies.

Where a baby has already developed an allergy to cows milk, partially hydrolyzed formulas should NOT be used. A specialty formula, where the protein is more completely broken down, may then be necessary. (Specialty formulas for milk allergies are only available on a doctor's prescription.)

Cows milk formula

Cows milk based infant formula is developed from modifying and treating regular cows milk. The protein quality is improved and salt levels are reduced. A range of different fats is added and the milk is supplemented with 13 essential vitamins and 11 essential minerals (including iron and calcium).

Cows milk formulas are classified as 'whey dominant' or 'casein dominant', which describes the main protein type in the formula. Whey dominant formula is easier to digest and is more suitable for babies under 6 months of age.

Although providing the same amount of calories per ounce, casein dominant formula is digested more slowly than whey dominant formula. Many 'follow-on' formulas and so called 'hungry baby' formulas are casein dominant.

Soy based formula

Strictly speaking soy is not milk as it is produced from whole soy beans or soy protein isolates. When soy based infant formula is made it is supplemented with essential fatty acids, vegetable oils, and carbohydrate in the form of maltodextrins, corn syrup solids or sucrose (sugar). Essential vitamins and minerals, including calcium and iron are added.

Soy infant formulas don't contain cows milk protein or lactose (sugar found in milk) and are intended for babies with particular health problems such as lactose intolerance or cows milk allergy. Approximately 50% of babies who are allergic to cows milk protein will also react to soy protein. These babies may need a special low-allergy infant formula (only available on a doctor's prescription).

Soy products contain chemicals which act like hormones. They are called phyto-estrogens . Although babies have been given soy formula from birth for many years with no known ill effects, it is not known if these chemicals have any long-term adverse effects on children. (Read more about recent concerns regarding soy infant formula.)

According to the American Academy of Pediatrics, "Healthy full-term infants should be given soy formula only when medically necessary".

Goats milk formula

Goats milk has a nutritional content similar to cows milk. In the production of goats milk infant formula the protein quality and salt levels have been improved and a range of different fats, essential vitamins and minerals have been added in the same way as it is for a cows milk formula.

Some babies with a sensitivity to cows milk protein tolerate goats milk formula but babies with a true cows milk allergy are frequently unable to tolerate goats milk formula as well.

Toddler formula

A number of toddler formulas are now available for children from 12 months to 2 years. Provided your child is eating a variety of nutritious foods there is NO significant benefit in using a toddler formula.

Thickening formula

Food thickeners can be added to thicken your baby's regular formula. There are a number of commercially produced powdered food thickeners available you can choose from, for example Instant Carobel® and Karicare Food Thickener®. Either of these can be used as a gel given before, during or after formula feeds or simply added to your baby's regular formula.

Cornstarch (corn flour) can be used to thicken the water BEFORE making up infant formula. For infants over 6 weeks of age, add 1 teaspoons to 3 oz of water. Water must be thickened and cooled prior to making up the formula. This is done by cooking the corn flour in the water.

Note:  It is important to be a aware that thickening formula increases the amount of calories per ounce by up to 18%. This can affect the nutritional balance of the formula and may also result in your baby drinking less formula.

If thickening of breast milk is required , food thickeners can be given as a gel or paste before, after or during a breastfeed.

In the past it was recommended to thicken infant formula by adding rice cereal . However, this practice is no longer recommended because adding cereal to infant formula changes the important nutritional balance of protein, fat and carbohydrates. Also it's inconvenient and can clog the feeding nipple.

There is NO evidence that thickened formula helps a baby to sleep through the night.

Changing infant formula

Some reasons it may be necessary to change the kind of formula that your baby drinks include...

If your baby has any of these conditions she will show definite symptoms. Without symptoms it's wise NOT to change the type of formula she's on, unless advised by her doctor to do so.

If your baby is fussy and irritable, it's tempting to change from one formula to another. However, this doesn't help. There are many reasons why your baby could be irritable or fuss with feeding, the type (or brand) of formula is rarely the reason or the solution.

You may wish to change from one brand to another because of cost or because a particular formula is easier to purchase. It's OK to do this, but make sure to check the instructions on the can, as preparation can differ between brands.

If you do change infant formula your baby's stools (poop) may change in color, thickness and/or smell.

Follow-on formula

A range of different 'follow-on' formulas are available for babies over 6 months. They contain a little more protein than 'starter' formulas (which are recommended for babies from birth to 6 months). Babies don't really need the extra protein at this age and there is no need to change your baby onto a follow-on formula unless you want to. It is fine to continue with a 'starter' formula until 12 months.

Although 'follow-on' formulas have the same number of calories as 'starter' formulas, hungry babies may find them more satisfying because of the extra protein. The main protein type in 'follow-on' formulas is casein (which is digested more slowly than whey dominant formulas). Some babies can become constipated for a few days when starting on a 'follow-on' formula.

Note: 'Follow-on' formulas are NOT recommended for babies under 6 months because of the higher level of protein.

How we can help!

Parents often blame infant formula for their baby's irritability, wakefulness and feeding difficulties, when only RARELY is it ever the cause of such behaviors. 

Through a consultation at we can assist you to explore the many possible reasons for your baby's distress until the exact cause in identified. We can also help by provide idividually tailored advice about how you can encourage your baby's contentment and sleep.

If you would like more information about our consultation service click here.

Written by Rowena Bennett

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