How to buy baby formula?

I'm bottle-feeding my baby. Which formula is best?

It's easy to feel overwhelmed in the formula aisle. Choosing the right nourishment for your baby is a pretty weighty decision, and there are lots of options.

When buying a formula, consider the form it comes in, the type of protein and carbohydrate it uses, and what other ingredients are included. In the end, you'll choose the formula that is best for your baby and your family's lifestyle.

What are the different forms of formula?

Formulas come in three basic forms: Ready-to-use, liquid concentrate, and powdered.

Ready-to-use formula is undoubtedly the most convenient – no mixing or measuring required, just open and serve. It's the kind of formula that hospitals often give to newborns. It's hygienic and especially helpful when you don't know whether you'll have access to safe water.

The convenience of ready-to-use formula comes at a price – ready-to-use formula costs about 20 percent more per ounce than powdered formula. The containers also take up more storage space in your cupboard and more space in the landfill, unless you can recycle the containers.

Once opened, ready-to-use formula has a short lifespan – it must be used within 48 hours. Also, because it often has a darker color than powdered formula, many moms complain that it's more likely to stain clothes.

Liquid concentrate formula requires mixing equal parts of water and formula (though always read specific instructions on the container carefully). Compared to ready-to-use formula, concentrate is less expensive and takes up less storage space. Compared to powdered formula, it's a little easier to prepare but more expensive.

Powdered formula is the most economical and the most environmentally friendly formula option. It takes up the least amount of space in transport, in your pantry, and in your trash can.

Powdered formula takes more time to prepare than other types of formula, and you must follow the directions exactly, but it has a one-month shelf life after the container has been opened. As with liquid concentrate formula, you can mix up just the right amount whenever you need it – as much or as little as you want – which is especially helpful if you're a breastfeeding mom who may only need an occasional supplemental bottle for your baby.

Note: You may be concerned about the chemical bisphenol A (BPA) that is present in the lining of cans of formula. Canned liquid formula does contain small amounts of BPA. Canned powdered formula is considered a safer choice because it usually contains far less BPA.

What are the different types of formula?

There's a formula to suit every baby's needs. But it's best to stick with one type and resist the urge to switch, even if your baby seems like he's not digesting the formula well at first.

Common problems like spitting up, gas, and colic are usually unrelated to your baby's diet. Most of the time, these problems have to do with your baby's still-maturing gastrointestinal tract – not what he's eating.

So try out a particular type of formula for at least a couple of weeks. After that, if your baby's still having trouble, talk to his doctor about switching.

Cow's-milk-based formula: Most formula available today has cow's milk as its main ingredient. The protein of the milk is significantly altered to make it easier to digest. (Your baby won't be able to digest regular cow's milk until after his first birthday.) The overwhelming majority of formula-fed and formula-supplemented babies do best with this type of formula because it has just the right balance of protein, carbohydrate, and fat and that's all that's needed.

Lactose-free formula: A case of lactose intolence or an inability to digest lactose – the sugar naturally found in milk – is rare. If your baby is lactose intolerant, his doctor will recommend a formula in which the lactose is replaced with a different sugar, such as corn syrup.

Soy-based formula: These formulas are made with a plant protein that, like the protein in cow's milk, is modified for easy digestion by babies. If you're a vegan, or if your baby has trouble digesting the altered cow's milk protein found in cow's-milk-based formula, the doctor may suggest a soy-based formula. Also, doctors usually recommend these formulas for babies with mild rectal bleeding, which may signal an allergic reaction to cow's milk protein.

If your baby is lactose intolerant, a soy-based formula may be a good alternative to a milk-based formula since the carbohydrate in soy is sucrose or glucose, not lactose.

You may want to talk with your baby's doctor about giving soy-based formula a try if your baby has colic. The evidence is far from conclusive, and most children with colic improve without to change in their diets, but some research suggests it's worth a try.

Keep in mind that about half of babies with a milk allergy are also allergic to soy – so if that's the reason you're considering switching to a soy-based formula, there's still a good chance your baby might not do well on it either.

Extensively hydrolyzed formula: In these formulas, the protein is broken down into smaller parts that are easier for your baby to digest than larger protein molecules. Your baby may need a hydrolyzed formula if he has multiple allergies or trouble absorbing nutrients (a common problem for preemies). The doctor may also suggest trying a hydrolyzed formula if your baby has a skin condition, such as eczema.

Formula for premature and low-birth-weight babies: These formulas often contain more calories and protein, as well as a more easily absorbed type of fat called medium-chain triglycerides (MCT). How much MCT is in these formulas varies by brand. Your baby's doctor will help you select the one that will help your baby gain just the right amount of weight.

Human milk fortifier: This product is used to enrich the nutrition of breastfed babies who have special needs. Some are designed to be mixed with breast milk, and some are meant to be fed alternately with breast milk.

Metabolic formula: If your baby has a disease that requires very specialized nutrition, he may need one of these specially developed formulas.

Other formula: New formulas come out all the time and are marketed to moms to help babies with digestion to relieve problems such as colic or acid reflux. These formulas have a protein ratio similar to breast milk and vary slightly in composition from regular formula – but some experts say they may not be any better.

"More often than not, specialty formulas are substantially more expensive and not significantly different in key nutritional value,” says KT Park, a pediatric gastroenterologist at Stanford’s Lucille Packard Children’s Hospital. “Babies undergo tremendous adaptation of their gastrointestinal tract during the first six months of life, which is normal. There are very limited scenarios in which infants would require the more expensive formulas.”

If you think your child might benefit from a specialty formula, ask your child's doctor about it before you stock up.