Part
1: The Evidence for Regulation
In earlier columns, I discussed the typical pattern of normal
growth in children. The only way to know if a child is growing
normally is to be able to look at a child’s pattern of
growth over time, instead of one weight value at a check-up.
This can be plotted on the growth charts from the Centers for
Disease Control used in health clinic offices and is best followed
on weight-for-age curves rather than the newer BMI-for-age curves.
Again, children tend to grow in a certain percentile that’s
right for them. Sometimes that child is in the 50th percentile,
sometimes above the 100th percentile, sometimes below the third.
If growth is consistent and there are no big swings up or down,
meaning crossing growth curves, he or she is probably doing
well. Again, this presumes that it’s not a problem for
kids to grow in the higher percentiles when their growth is
stable. (Not all professionals agree on this, but as we talk
more about childhood weight regulation, I believe you’ll
see the sense in this.)
However, some kids are clearly not growing well. There are many
children who are gaining high amounts of weight, over and above
what their genes would dictate. In this column, we’ll begin
to talk about kids who gain too much weight.
Modern Life
It is easy to blame the “toxic food environment” of
America today for the increase in number of kids who are heavy.
We know that people eat out more often, fast food portions have
exploded in size, children seem to be consuming pop and candy
everywhere (including in school), school lunches sometimes seem
straight out of the midway at the county fair.... We also know
that children are much more sedentary than they used to be,
in general. Just take walking to school, for example. In my
small town, a couple of years ago, we did away with K-6 schools
and reconfigured the schools to a K-4 and 5-6 format. The fifth
and sixth graders in town are now bunched together in two schools
and no one goes to one school for seven years anymore. This
means all children in our town will end up being bussed or driven
to school for at least two years of elementary, depending on
where they live. Doing away with neighborhood schools has happened
all over. We know, as well, that kids spend enormous amounts
of time each day passively watching one thing or another in
front of screens, whether viewing television, playing a video
game, or instant messaging with friends. The average child in
America spends about 4.5 hours/day in front of screens and 24%
of preschoolers have a T.V. in their bedrooms! Yikes.
We can hardly think this is good for our kids. There are many,
many reasons to improve dietary quality and activity involvement
for our children (and, of course, the Weighty Wisdom dietitian
will address this!). But does it explain why kids are having
trouble with weight regulation? Well, if it did, why wouldn’t
all kids who eat fast food, watch too much television, and drink
pop be struggling with weight? Are the ones who seem to be growing
well only those kids who are not doing these things? Or are
they the naturally really skinny ones who wouldn’t gain
weight even if you fed them a sack of sugar and a can of shortening
at every meal? Why is it that some kids seem to know how to
regulate and grow the right amount even within very different
environments? Before that question gets addressed, I’ll
discuss regulation of eating in general.
The
Three Internal Regulators
All humans rely on three internal regulators to help them
know how much to eat. We’re all born with them, and if
only we could all grow up hanging on to our ability to listen
to these regulators, there would be a lot fewer adult struggles
with eating and weight. Hunger is the drive for fuel. We feel
hunger in our stomachs and in other parts of the body—blood
sugar gets low, you may get a headache, feel tired, or get
shaky if you’ve gone too long without eating. We all
tend to get crabby when too hungry—and the younger ones
among us may throw full tantrums!
Appetite is the drive for pleasurable food. Humans have an
inborn preference for sweetness, but all other taste preferences
seem to be learned. This is how children all over the world
learn to like what they’re served in their culture (see
below!) Some children seem hardwired to be very adventuresome
in trying and liking new foods. Others are on the opposite
end of the spectrum. New foods are scary and feeling brave
enough to even sample them, never mind eat them often, comes
slowly.
Satiation means reaching our stopping point—we’ve
had enough fuel and enough of the taste of a food. Sometimes
with eating we overdo it or underdo it for a variety of reasons.
But then our internal signals will just let us know to eat
a bit less or more the next time. If this didn’t happen,
how could kids grow in a stable manner or adults stay at a
stable weight? These regulators are managed in pretty complex
ways by our bodies, with chemical hormones and physical sensors.
But thank goodness we don’t have to know too much about
how our bodies do this and we don’t have to try to manage
it—we just need to pay attention to our body signals.
You may be an adult who has spent as long as you can remember
trying to regulate your own weight by counting calories, perhaps
fat grams, or now, of course, carbohydrates. But remember
that food has been labeled with this information only very,
very recently in human history (in my lifetime as a dietitian,
in fact)—so our bodies must have known how to regulate
from the inside since humans have been humans.
Kids Know How to Regulate
Children are born knowing how to regulate their food intake—to
listen to those three internal regulators—even with different
types of food. Studies have shown that a baby fed watered-down
formula will drink more of it to get the right amount of calories
to grow the way he was intended to grow. Babies will also
consume different amounts on different days and grow very
evenly. Babies seem to know how to eat exactly what they need
for the type of body they’re supposed to have. Studies
have also shown that the thinnest, most active babies typically
eat much more food than the fattest babies (sometimes twice
as much!) and that body size cannot predict calorie requirement
for infants. Think about breastfed babies you’ve known.
Would you agree that it’s pretty hard to overfeed a breastfed
baby? (A little more about this later.) Yet they seem to come
in all sizes—some are very chubby, some are slimmer.
Again, it’s not necessarily the amount they’re eating
that determines what size children end up—rather, the
size they’re supposed to end up being seems to determine
how much they eat and what their bodies do with the food.
Maybe you’re thinking, sure babies can regulate with
milk or formula—the taste doesn’t change so it’s
not very challenging...but we’ll see that kids regulate
with food, too.
From The Milk Feeding To Solid Food
As kids move beyond the baby stage, they begin to eat a variety
of foods. Do they hang on to this ability to eat what their
bodies tell them they need to grow in their own unique pattern?
The answer is yes: if children are fed in the right manner,
they can continue to regulate eating a whole variety of foods.
More studies have shown the same thing we see with infants:
children who weigh more are not necessarily eating more than
their thinner peers. Often they’re eating less. In the
next column we’ll talk about the one type of food that
truly appears to interfere with a child’s ability to
regulate intake. But in general, the types of foods children
eat and regulate with just fine vary tremendously. Kids in
the United States regulate with fast food burgers or homemade
meatloaf, tuna noodle casserole and salmon filet, french fries
and potatoes. If they’re vegetarian—like many children
all over the world—they’ll probably regulate and
grow just fine with beans, grains, and usually some sort of
dairy foods. Kids in Mongolia grow up eating their native
foods (mutton and mare’s milk), as do kids from Peru—whether
Peru, South America (potato cheese casserole or fish cooked
with lime) or Peru, Indiana (mac-n-cheese?). Kids can regulate
with seal meat and whale blubber (eaten by Inuits in the far
north) and kangaroo meat (a staple food for aboriginal people
from Australia). Kids might regulate with pasta in Italy or
rice in Japan and India or millet (a staple grain) in Africa
or cassava (a potato-like starchy vegetable) in Brazil. All
over the world, children eat their native foods and grow well,
if they have enough food. What I’m saying is that for
kids to begin to grow poorly, something has to disrupt their
natural ability to regulate with all different types of food.
Many believe that kids can’t regulate with the types
of “junk” foods around today in America—but
is it the food itself or something else that’s getting
them off course?
Again, kids are born equipped with regulators. It’s the
adult’s job to create an eating environment that provides
not only nutritious food but also the calmness and predictability
for children to be able to pay attention to their body signals.
If we are to figure out why more kids these days seem to be
gaining excess weight, we have to pay more attention to HOW
children are being fed rather than WHAT they are eating. Stay
tuned!
In the next Weighty Wisdom column, coming soon:
Part Two: Interfering with Eating Regulators: What Goes Wrong
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