Eating Right: Infant Nutrition

My training is filled with newborn medicine. The first year, I spend one-third of the year taking care of babies, plus I see a lot of babies in my clinic each week (we have at least 2 newborn visits each week). So, naturally, I have learned a lot about infant nutrition. This post, I'm going to primarily talk about formula and transition to table foods, but in another post, I'll talk about the reported benefits of breastfeeding. We'll do this Q&A style today.

What's with all these different formulas? 

There are dozens of different types of formula. For the most part, they are marketed for different groups. There are two main categories: cow's milk based formulas, and soy formulas.

Cow's milk formulas process cow's milk heavily into something resembling human breastmilk. The proteins are broken down and adjusted to look more like human breastmilk, additional lactose (milk sugar) is added, and the milk fat is removed and replaced with different types of fat. Note that all this adjustment actually makes the formula very different from cow's milk, so there is no contraindication when we say that you should not give your child milk until they are 12 months old.

A subset of cow's milk formulas are the hydrolyzed, or hypoallergenic, or sometimes called elemental, formulas. These are based on cow's milk, but are further broken down so that the proteins are short, and thus less likely to cause allergic reactions.

Soy milk formulas are designed primarily for vegetarian/vegan parents who do not want to give their child cow's milk based formulas.

There are also a handful of special formulas for children with very specific metabolic syndromes, which are determined by the newborn screen, and not applicable for most children. They tend to be more expensive, and out of the price range of many parents as well.

So, which formula is best?

There isn't a hard and fast rule for this. For most babies, a general cow's milk formula fortified with iron is sufficient. This also tends to be the one that most people start out with, and as such, makes up a huge portion of the market. So, it also tends to be easier to find and sometimes cheaper.

When should I switch formulas? 

You want to talk this over with your pediatrician. Some reasons your pediatrician may recommend a different formula may include a significant family history of allergies (especially food allergies), a milk protein intolerance, or a metabolic disorder that requires a certain type of formula.

A significant family history of allergies may predispose your baby to getting allergies to foods, so to minimize that risk, a hypoallergenic, or elemental, formula may be recommended. These may help up to 90% of babies in these situations delay the onset of allergies or avoid them all together.

A milk protein intolerance most commonly presents as blood in the baby's stool. It does not represent a true allergy, but rather a minor reaction to the protein in the cow's milk formulas. However, there can be significant cross sensitivity to the proteins in the soy formulas, so again, a hypoallergenic formula may be recommended.

Generally, babies do not have lactose intolerance. This is something that tends to develop in older children and adults due to a deficiency in the chemical in the gut that breaks down the milk sugar. Babies are designed to break down this sugar, as human breastmilk has it in large quantities. However, there are rare cases of lactose intolerance in babies, and in these children, a lactose-free formula may be used.

How long should I give my baby formula?

You should give your baby formula or breastmilk ONLY until they are at least 4 months old, unless otherwise suggested by your pediatrician. They should not be given juices, sodas, or table food. Formula or breastmilk will provide all the nutrition they need up to about 6-7 months of age. After that, they should continue to get formula until 1 year of age, when they can be switched to cow's milk (or soy milk, etc) as their milk requirement.

How should I introduce foods? 

When the child is able to sit up on their own and express interest in the rest of the family eating, you may start introducing 'solid' foods. These should be completely pureed. Most pediatricians will recommend starting with an iron fortified rice cereal or oatmeal or something of that nature, but it's acceptable to start with another iron-rich food, such as finely ground meat.

Following that, you can start introducing different vegetables and fruits. Babies tend to like fruits more than the vegetables, because they are sweeter, but it is important for them to have a balanced diet, so introduce different vegetables early and often. You should feed your baby only single ingredient foods at first--sweet potatoes, peas, carrots, apples, whatever, so long as there is only one thing in the puree. Then, wait three days before introducing a new food. This technique allows you to monitor any allergies or intolerances that may develop in the baby, so you know exactly which food caused it.

If your baby does not like a certain food when you first introduce it, don't give up. Mix it with a food they previously did like and tolerated, and then slowly increase the amount of the new food until there is no more of the former food.

As they get older, you can start introducing new textures, and by 1 year of age, they should be able to eat small finger foods on their own.

Is there any food I can't give my child?

Infants under one year of age should not be given honey. This is because in the processing of honey, there is a change for a bacteria called botulism to get into it, which can then multiple in the infant's intestines and cause a serious illness.

You should also not give your infant under age 1 cow's milk. Yes, I know I just talked about cow's milk formula extensively, but these formulas have been heavily altered and processed to meet the needs of babies. Cow's milk does not have the nutrients babies need and has a high amount of sodium, potassium, and other solutes that may stress the kidneys of an infant. After 12 months, their kidneys have matured enough to allow this. Note that unless your pediatrician says otherwise, you should start with whole milk, because toddlers need the extra fat for brain development.

How's that for a whirlwind tour of nutrition? Any additional questions, let me know at the contact button above or in the comments below.

Eating Right: The Moving Target of Good Nutrition

Between the various 'diets' (which should more accurately be called 'weight loss technique') and trends going around, it can be hard to get a good idea of what you should be eating. There are those who say meat is horrible (for one reason or another), others who say you should eat the way of the cave-man. There's the low-fat, the low-protein, and the low-carb fabs. But, really, what should you eat?

In elementary school, I was taught the food pyramid. You know, the one where sugar and salt were at the top, and meant to be used sparingly, and grains made up the heavy base at the bottom. In fact, in 1990, the US government recommended 2 servings of fruit, 3 servings of vegetables, and 6 servings of grain daily, along with a diet low in fats, and especially saturated fats.

Recently, the food pyramid has changed. The new pyramid, referred to as My Pyramid, changed the recommendations some. It placed a heavier emphasis on whole grains (at least 3 servings per day), oils for fats, and fewer meat and more of other sources of protein. It also placed heavier emphasis on physical activity with the stairs on the side of the pyramid.

Even more recently, the pyramid has been done away with completely, in favor of the My Plate method. Personally, this is my favorite way of showing portion sizes during meals, because it can be easily demonstrated with hands. You place your hands together. Your left palm represents the amount of meat or protein you should eat. For smaller kids, it's a smaller amount, and for adults, it's a larger amount. Your right palm represents the amount of grains, such as rice, bread, etc, you should have with each meal. Your fingers, then, represent the vegetables you should eat. You can spread your fingers to get more vegetables, but cannot expand your palms to get more protein or grains. Since most kids don't get enough vegetables on a day-to-day basis, this is a great way of encouraging them to eat more if they are still hungry.

For general child health, we make a few other recommendations. For instance, the dietary guidelines put out by the government only apply to those over age 2. Under that, we recommend whole milk because the children need the extra fat for brain development. Things like soda and koolaid are not recommended, because they provide no vitamins, minerals, or any other nutrients besides sugar. Even fruit juice, which provides some of the benefits of fruits and vegetables, aren't recommended in lieu of the actual vegetables, because you get the fiber and feel fuller when you actually eat the vegetables.

Milk is both good and bad. Kids all need calcium in order to develop strong bones, especially in adolescence. However, too much calcium can also work against you, and decrease the ability of the blood to carry oxygen, resulting in a very tired and potentially sickly kid. So, we recommend a total of 2-3 cups (or 16-24 oz) per day of milk or other dairy products. Another issue we see a lot is that kids who drink a lot of milk will get full, so won't eat as much solid foods, and it is still important once they are past 6 months to a year for them to get other nutrients. And please, no milk at bedtime--it does have sugar that can rot the teeth.

Fiber is also super important. Why? Because all kids are constipated. I've seen so many kids come in with abdominal pain, we get an x-ray, and see their intestines just filled to the brim with stool. I've seen one kid who was so constipated, that he had to get surgery to fix the problem. Fiber comes in all fruits and vegetables, but also whole grains. And when in doubt, Miralax is an amazing medicine.

So, a summary of our recommendations:
- A generally balanced diet, with sufficient protein, fat, and carbohydrates for growth. If they're gaining weight, they're getting enough calories.
- Lots of vegetables, and some fruits. In whole form.
- Limit juices, even fruit juices
- Lots of fiber
- Milk, but in limited amounts and not at bedtime

Growing Big: The Issue of Childhood Obesity

Yes, it's time we talk about that sticky topic: obesity. It's a concern across all of American society, but we as pediatricians are specifically looking to curb childhood obesity, as it increases your chance of being obese as an adult and has its own health risks. Obese children are more likely to have early heart disease than those who are not obese. They are at risk of having bone and joint problems (due both to being obese and due to lack of exercise), and are much more likely to develop type 2 diabetes, a disease that used to be considered an adult-only disease. Obesity can also affect school performance, not only because of the psychological impacts of being obese (teasing, bullying, etc), but also because it can result in sleep apnea, a condition where you stop breathing periodically throughout the night, which can impact the ability to concentrate in school.

Clearly, there are many effects of obesity on health, which is why we care so much about it. But how bad of a problem is obesity, really?

First, let's start by defining obesity.

In adults, it's pretty straight-forward. We take a ratio of your height and your weight, a number referred to as your BMI, and compare it to what we've established as normals. Essentially, under 20 is considered 'underweight', between 20 and 25 is a healthy weight, between 25 and 30 is overweight, and greater than 30 is obese (with greater than 35 being considered morbidly obese). This tool is used because it allows a better comparison between a thin, short woman, to a heavy-set, tall man. However, it's not perfect. Muscle weighs more than fat, so someone could have a favorable body fat percentage, but have an elevated BMI. Still, it is one of the easiest measures we have of body fat, so it is the one used most frequently.

In children, though, the normals are understandably different. A baby is going to have a higher amount of body fat than a teenager should, because they use it for warmth. Also, when kids go through puberty, a lot of things about their body changes, often including their BMI. Kids also often grow taller faster than they grow fatter, so often have BMIs in what we would consider underweight in adults.

So, we use growth charts to help us out. If you've ever seen a pediatrician, you've probably seen these at least once. We have a chart for length (height in standing kids), one for weight, and one for length-vs-weight or BMI, depending on the age (BMI is used for children older than 2). There are growth charts available for children with different disorders, such as Turner's syndrome, Down Syndrome, PKU, etc, that allows us to track a child's growth compared to other children his age.

Thus, when we say a child is obese, we are using a slightly different set of criteria. We use these growth charts and define obesity as anything over the 95th percentile, meaning children who have a higher BMI than 95% of their peers are considered obese. Overweight is defined as a BMI between the 85th and 95th percentiles.

Back to how bad of a problem this really is. In 2011, approximately 8.1% of kids aged 0 to 2 are obese; the rate is higher among girls (11.4% vs 5%). We are, thankfully, seeing a decrease in obesity rates in children under age 2 compared to 2003, but that doesn't mean we are out of the woods yet. Approximately 31.8% of kids aged 2 to 19 were either overweight or obese. That means that 1 in 3 kids is bigger than they should be.

This is better than the adult numbers, where upwards of 60% of adults are overweight or obese, but realistically, I see it as only a matter of time before kids enter that trend, which is why it's so important to establish good habits early in life.