Starting Solid Foods: Are We Doing It Right?
http://www.medscape.com/viewarticle/745786_2
Medscape: Dr. Greene, it is clear that
among the myriad health benefits attributed to breast feeding in infancy
is a favorable effect on weight gain. Can you summarize some of these
data?
Dr. Greene: The more we learn about
breastfeeding, the more we learn about how powerful it is for babies in a
variety of different ways. The immune benefits are incomparable, the
nutrition benefits are incomparable, the taste benefits are
incomparable. Breast milk tastes different every single feeding, which
exposes the baby to a variety of flavors, and studies have shown that
what a nursing mother eats can help predispose her child to learn to
like later.
The breastfeeding and obesity question is one that has been highly
controversial. It is biologically plausible that breastfeeding could
have a powerful programming effect in preventing overweight or obesity.
We know that there are significantly higher plasma insulin
concentrations in infants who are bottle-fed compared with those who are
breastfed, which would be expected to change fat deposition and
development of fat cells.
We also know that breast milk contains biologic factors that can
inhibit adipocyte differentiation in vitro. The amount of calories
metabolized and the protein intake of breastfed kids is considerably
lower than in infants who have been formula-raised. In controlled
prospective studies, that lower protein content accumulated in breast
milk has been demonstrated to be associated with lower likelihood of
obesity.
So there are lots of reasons to think that breast milk would, in fact, be protective.
However, around the beginning of the 21st century, there were a
number of observational studies examining breastfeeding and later
obesity or overweight. While some of them showed a protective effect, a
number of them were unable to demonstrate a statistically significant
effect, which has led to a lot of controversy in the area. Most
recently, there was an excellent review article that appeared in the
April 27, 2011 online version of the
American Journal of Clinical Nutrition that looked at breastfeeding vs formula feeding.
The researchers hypothesized that the reasons for the disparate
outcomes in previous studies may have been because the positive effect
of breastfeeding on weight may be confined to only those children at the
higher end of the body mass index (BMI) curve. To examine this
possibility, they looked at data from over 14,000 children ranging in
age from 54 to 88 months who received a school health examination in
Germany between 1999 and 2000. Their analysis controlled for a number of
potential influences of weight including sex, age, television viewing,
maternal BMI, parental education, maternal smoking during pregnancy, and
early weight gain. What they found was that the protective effect of
breastfeeding was indeed confined to children between the 90th and 97th
percentile with a reduction in BMI of -0.23 and -0.26, respectively. So,
not all of the questions have been answered yet. It is not conclusively
proven but it is biologically plausible, with several large
meta-analyses and this most current paper showing an effect. It is yet
another good reason to recommend breastfeeding to families.
Medscape: The Healthy People 2020
target for the proportion of mothers who ever breastfeed their babies
is 81% with specific goals of 60% at 6 months and 34% at 1 year. How are
we doing in meeting those goals? Are there particular women to whom we
should devote increased attention?
Dr. Greene: We are not at those goals
yet by a considerable stretch, but there is good reason to believe that
we can meet those goals by 2020. Right now, about 75% of women are
breastfeeding ever. Back in 2000, only about 70% of women were
breastfeeding ever. A similar increase over the rest of this decade is
certainly achievable.
The goal for percentage of women still breastfeeding at 6 months is
60%. Right now, we are only at about 43%. In 2000, we were only at 34%,
so if we can keep our momentum going, we should be able to get there.
Finally, our goal is to have 34% of women doing at least some
breastfeeding at a year. Right now, only 22% of women are nursing at
their infant's first birthday but only 15% were doing so back in 2000.
So again, reasonably, we can meet those goals.
There are 2 groups of women on whom to particularly focus attention.
The first are working women. About half the American workforce is women.
Returning to work can be a big obstacle to continued nursing. Balancing
that struggle of working and breastfeeding is difficult and only about a
quarter of employers provide onsite support or even just a room for
women who want to nurse. Making the workplace favorable for
breastfeeding is a huge issue that must be dealt with.
The other group that should receive attention is brand new mothers in
the immediate postpartum period. Right now, about 4% of babies in the
United States are born in hospitals that are designated
baby-friendly
and encourage exclusive breastfeeding at the beginning of life. Almost a
quarter of breastfed babies receive formula within the first 2 days of
life. If we can teach new mothers what to expect and how breastfeeding
works in the first critical days after delivery, I think we can go a
long way towards meeting those goals.
Medscape: A number of other factors are
recognized to be important in the development of feeding preferences and
practices in infants and toddlers, including timing of first solids,
types of solids, and even the rapidity with which a child ingests these
foods. Can you describe some of the most important of these studies and
their implications for parent education?
Dr. Greene: A very important study
from the Division of Gastroenterology and Nutrition at Children's
Hospital Boston was published in February 2011.The researchers examined the timing of solid food introduction and the
risk for obesity in preschoolers by following 847 children
prospectively. The formula-fed, though not the breast-fed, children who
were introduced to solids before 4 months of age were 6 times more
likely to end up obese at 3 years old. The researchers speculated that
these children actually increased their energy intake as a result of the
inclusion of solid foods. It appeared to change the amount that they
ate and the way their body dealt with calories later on, an example of
metabolic and possibly flavor programming.
Another interesting area of research has examined the impact of early
taste exposures on lasting taste preferences. We are all familiar with
the baby food window, the time that they are putting everything they can
find into their mouth. It appears that children who sample a vegetable
or a fruit on average 6-10 times have a high likelihood of developing a
preference for that food.
Unfortunately, the
Feeding of Infants and Toddlers Study (FITS),
which was an examination of feeding habits, found that in the 21st
century 94% of parents give up on feeding a new vegetable by 5 times or
fewer.
Parents appear to decide the baby is not going to learn to like it.
Only 1 or 2 parents in 100 will try it a full 10 times. So one of the
things that we can do to teach good nutrition habits is to encourage
parents to provide a variety of flavors and do it multiple times in a
relaxed positive environment. In a study published in 2007, researchers
asked parents what was their child's least favorite vegetable and then
asked them to give their baby just a bite of that food as the first bite
of solids in a particular meal, without forcing the child to consume
it, and to do that every day for a week.
At the end of the week, 85% of those kids who hated that vegetable had
come to really enjoy it. Some 70% of them still liked it a year later
when they were in the picky meal phobia stage where toddlers have a
built-in fear of new foods and new sources of foods.
In the last year, there have been a couple of interesting studies
looking at the pace of feeding in older children. One of these was a
study that looked at the feeding behaviors of 4-year-olds. The
researchers placed a big buffet in front of these children and observed
them eating at length.
They looked at which foods they chose, whether it was high calorie,
junk food, or dessert. The researchers also looked at the messages the
parents provided to the children to "eat more of this" or "don’t eat
more of that." The study also examined how quickly the children ate. In
short, every different aspect of the child's eating behavior over the
course of this buffet was examined and recorded.
The children returned a couple of years later to see which ones had
become obese. The original data were re-examined to see if there was
something about these children's eating habits at age 4 years that might
have been predictive. What the authors found, surprisingly, was it was
not the total number of calories consumed, whether a child went straight
for the dessert, or if the child chose the junk food that predicted
obesity. There were 2 things that did correlate with later obesity. The
first was the amount of time the child spent at the table. Those who
were there for 39 minutes or more and kept eating were
less
likely to become obese than the children who were at the table for 29
minutes or fewer.
Taking longer for a meal appeared to be protective. An
even stronger correlation, however, was found between the number of
bites per minute and obesity. Those children who had eaten 3.1 bites per
minute or more were much more likely to become obese than those who ate
2.2 bites per minute or fewer. That was a difference between about a
bite every 20 seconds and a bite every 27 seconds. A 7-second difference
in bites was enough to make a dramatic difference in weight.
A study of older children published in 2010 confirmed this association between speed of eating and weight loss.
In this study, obese children participating in a hospital-based
intervention were randomly assigned to 1 of 2 groups that received
identical lifestyle modification education. The intervention group was
also given a computerized device that provided real-time feedback that
taught them to slow down their pace of eating. The intervention lasted a
year for both groups. At the conclusion, both groups of children did
lose weight; both groups had healthier BMIs and better cholesterol
levels as well as other blood markers. However, the group that had
received the feedback had a significantly better outcome in every
category. Six months later with no intervening intervention, that group
that had learned to slow down their eating had continued to make
improvements. Slowing down the pace of eating to 1 bite every 30 seconds
made a difference
Looking at infants, I wonder if this may be one of the reasons that
breastfeeding is protective; breastfed babies have to work to eat.
Perhaps passive feeding bottles are problematic because large amounts of
formula can come in without the baby being able to regulate how much
they are getting, resulting in feeding too quickly and too easily.
Medscape: The American Academy of Pediatrics' Baby Center
guidelines for parents of infants 4-6 months of age recommends pureed
food and iron-fortified cereal. What more specific recommendations do
you make for infants in your practice?
Dr. Greene: The current
recommendations for feeding babies are not working. There was a 2011
study that looked at the obesity epidemic, which is no longer news, but
this was news.At 9 months of age, 32% of the American babies in the study were
already overweight or obese. This is dramatic and very different from
earlier decades. This was not just healthy, chubby babies -- these were
children who were really overweight or obese by 9 months old.
At 2 years old, that percentage of obese children was 34%, a small
increase. These figures illustrate that the bulk of the obesity epidemic
is already starting in early childhood. So the thing that we need to be
doing if we want to solve the obesity epidemic is to look at what is
happening at 8 months old.
A lot of our focus has been on reducing
screen time, increasing exercise, providing healthier meals in schools,
reducing fast food and drive-through windows, and getting rid of soda,
and those are really good interventions. I support every one of them.
But at 8 months old, soda is not a big problem for most babies,
certainly not for a third of babies. Lack of exercise is not a big issue
for most babies, certainly not a third of babies. Drive-through windows
even are not a big issue at 8 months old. What is it? If we want to
find out what the big issue is, I would suggest we look at where kids
are getting their calories. There must be some modifiable risk factor
that is causing this obesity increase. I say modifiable because it did
not used to be this way.
What many people do not realize is that the number one source of
solid food calories for most babies in the United States, the number one
calorie source from all solid foods, is refined white flour, refined
grains, what we call white rice cereal. It is no wonder, I think, that
we are ending up with a crop of obese children; we are priming them both
metabolically and from a flavor perspective to like exactly the wrong
thing. So I take strong issue with the idea of starting with white rice
cereal.
Medscape: You have initiated a campaign called WhiteOut
with a goal of introducing whole grains during the first year of life.
Can you describe this program? What was the impetus for its development?
Can you discuss the scientific foundation?
Dr. Greene: The specific goal of the
WhiteOut Campaign is to eliminate white rice cereal for babies by
Thanksgiving of 2011 -- to whiteout or erase this, what I would term,
mistake of the late 20th century. This is a grassroots campaign of
patients, physicians, parents, everybody that we can get involved. There
is no funding or commercial interest in this whatsoever. It is a public
health effort to change the way babies are fed.
The taglines are very simple: let every child's first grain be a
whole grain. They won't mind; they will thank us for it. And let every
child's first food be a real food, something that we want them to learn
to like later.
This is not specifically saying that the first food should be a grain
or shouldn't be a grain. That is not the issue. Rather, our point is to
just skip the white rice cereal. When parents do introduce grains, they
should be whole grains.
Think about the reasons for choosing a first food for babies. One
reason may be because the food is nutritionally dense and gives them
what they need right now. That should not be a major reason because
infants are getting most of their nutrients from breast milk or formula,
but it is a legitimate reason. By that parameter, white rice flour
offers no benefit; it is a food we would call a junk food at any other
time. It does have a few added vitamins and minerals but you can get
those in a whole grain just as easily.
Another reason that we might choose a first food is that it is
hypoallergenic. However, the American Academy of Pediatrics has said
that there is no food that we need to delay beyond 4-6 months of age
because of concerns that it might increase allergies. That, therefore,
is not a good reason for white rice cereal.
Another reason to choose a food might be because it is
iron-fortified. There are healthy alternatives, whole grain oatmeal and
whole grain brown rice cereals, that provide iron fortification similar
to that found in white rice cereal. Or you could choose foods that are
naturally iron-dense, such as meat.
The final major reason for choosing a food early on is to teach a child to like that taste. White flour is something we don't
want
to teach children to like. Earlier, we talked about the need to expose a
child to a particular food 6-10 times on average to allow the baby to
learn to like it and continue to like it. However, 94% of parents won't
do this. The one food the parents feed again and again is white rice
cereal. Most babies in the United States will receive that food 10 or 15
times, often before they have any other bite of food, solidly
programming them to like it.
It is no wonder that kids' meals across the United States include
foods like mac-'n-cheese, white flour buns on hamburgers and hotdogs,
chicken parts dipped in white flour in order to make them appealing for
kids.
White flour and refined sweets are the number 1 source of calories
throughout childhood. We are setting children up for that.
The new US Departments of Agriculture and Health and Human Services
dietary guidelines recommend reductions in the following 5 foods in the American diet:
- Sodium, which is not a big issue for babies;
- Alcohol, which hopefully is not an issue for any babies;
- Solid fats, some of which are needed in
the rapid growth first year of life, which is a time where fatty profile
is not the big obesity issue;
- Added sugars, which babies should not be getting and is not a major part of their diet; and
- Refined grains, which are the number one source of solid food calories -- something that should be reduced. This is our culprit.
On the flipside, the dietary guidelines encourage the inclusion of
whole grains in diets because of evidence that indicates that whole
grains can reduce the risk for cardiovascular disease, are associated
with lower body weight, and, as an additional benefit, are high in
fiber. There is also some evidence demonstrating that diets higher in
whole grains may reduce the incidence of type 2 diabetes. American
actually fall farther short in encouraging the use of whole grains as a
replacement for refined grains than we do in getting kids to like
vegetables. Yet, many parents get the recommendation to start their
child on a refined grain and that message is repeated again and again. I
think it is the worst choice we could make for a first food.
Medscape: What about availability of, for
example, brown rice cereals? Are whole grain choices for infants
readily available and, if so, are there cost implications?
Dr. Greene: The same manufacturers
that make the refined white flour cereals also make whole grain versions
and often at a very similar price. So for families who are buying
cereal, there is not much of a cost implication. However, we have to
keep in mind that about half of the babies in the United States are fed
by the Women, Infants and Children (WIC) program, and white rice cereal
is the dominant calorie source for foods provided to these families for
use in the first year of life. For families on WIC who wish to provide
their infant with whole grain cereal, there is a cost implication.
Availability is the other issue. While whole grain cereals are
available in some store chains, they are not found in all of them yet. I
have looked in a number of stores and found only white rice cereal on
the shelves. That is one of the goals of WhiteOut: to change the store
shelves this year to make whole grain cereals easy and available for
families.
Another initiative of the WhiteOut program is to talk to decision
makers within the WIC program about providing a whole grain cereal
option for families. I can't think of any reason not to do that. Long
term, we would like to actually replace the white flour option for
babies and not even have those covered under WIC.
Medscape: Can you discuss the parent education provided by the WhiteOut campaign?
Dr. Greene: For babies to see and
taste the same foods that the family is eating is a very powerful thing.
It is the way that babies were fed through most of human history. The
whole idea of baby food is a pretty modern invention. When my father was
born, it was not that way. By the time I was born, it was a rite of
passage to eat processed baby food. Our campaign aims to change that.
My book
Feeding Baby Green is a simple program to teach
children to recognize and truly enjoy healthy amounts of great food --
something I call Nutritional Intelligence. There are many supporting
materials on my
Website and on the
WhiteOut page.
One of the options I recommend for families who want to start with
grains is to include brown rice in the family diet and to make their own
brown rice cereal themselves. I think that is one excellent way to go.
My preference for the first bite is to give a baby a bite of
something they've seen the parent eat, something they've seen come from
the produce aisle, a community supported agricultural farm, a garden, or
a farmers' market. I love avocados, sweet potatoes (cooked until soft),
or bananas as a first bite -- mashed with a fork with some of the
breast milk or formula they've already been getting.
Parents have a strong inner drive to feed their babies well. The
simple tip to let the first grain be a whole grain often makes sense to
them when they hear it. How much better when they hear it from their
child's own provider!
