Prenatal, infancy, early childhood — factors in all may affect a
person’s future weight and health.
Pam Levin's daughter weighed less than 5 pounds at birth. But by the
time the child turned 3, Levin and her husband had begun to bristle at
some of the comments about her. "People would say, ‘She's chunky' or
‘She's a big girl,'" Levin says.
The comments may not have been tactful, but the Los Angeles mom caught
herself wondering if they were true. Was the adorable, easygoing
preschooler overweight? During the child's first year of life, she had
been smaller than 95% of children her age, according to pediatric growth
charts, weighing about 17 pounds on her first birthday. But her weight
had increased, and kept increasing, until she was 43 pounds at age 3
1/2.
"All of a sudden she's was on the 50th percentile, then the 75th, then
99th," Levin recalls. "You say, ‘Wait a minute. Something's not right.'"
Today, one of every three U.S. children is overweight — but it's much
easier to prevent obesity than to treat it. That's why pediatric obesity
experts now say intervention should begin early — very early. The risk
of becoming overweight or obese, it increasingly seems, begins before a
child is born, establishes roots in infancy and may be entrenched by the
time a tot starts kindergarten.
In recent studies, researchers concluded that some risk factors for
childhood obesity exist even before birth. Further, they've found, obese
3-year-olds already show the signs of inflammation that is linked to
heart disease in adults.
The notion that a person's lifelong weight trajectory might be
programmed early in life is startling — and potentially revolutionary,
says Dr. Nicolas Stettler, an associate professor of pediatrics and
epidemiology at the University of Pennsylvania.
"If we can identify a short period of time where an intervention can
have a long-lasting effect, that could be very promising," he says.
So far, most of the evidence that the early years affect weight into
adulthood comes from observational or epidemiological studies. There are
few randomized, controlled trials — the most scientifically rigorous
kind that prove cause and effect, says Dr. Elsie M. Taveras, an
assistant professor of population medicine and pediatrics at Harvard
Medical School. But she points out, "We have pretty strong observational
studies for a good number of risk factors in the prenatal, infancy and
early childhood period."
In her paper, published March 1 in the journal Pediatrics, Taveras and
her colleagues summarized more than one dozen factors in the prenatal
period through age 5 that can increase the likelihood of later obesity.
The research was based on a study of 1,826 mother-child pairs from
pregnancy through the child's first five years of life.
Many were behaviors that are often passed down through generations and
are more likely to be found in black and Latino families than in white
families, possibly accounting for the high rates of obesity in those
communities. For example, black and Latino infants are more likely to be
fed solid food before 4 months of age and to sleep less as infants.
Each of the three early-life stages — prenatal, infancy and early
childhood — comes with its own risk factors. But each also comes with
the chance to intervene, breaking a lifetime cycle of obesity and
dieting before it starts.
Prenatal
Several risk factors likely begin with the mother — even before she's a
mother.
Almost half of U.S. women today begin pregnancy overweight or obese,
automatically increasing the likelihood that their babies will be born
either too small or too large, both of which increase the risk of
obesity for the child later in life.
Further, studies show that how much weight a pregnant woman gains and
whether she develops gestational diabetes both can influence her child's
weight in adulthood.
The odds of being overweight at age 7 were 48% higher for children of
women who gained more weight than recommended during pregnancy compared
with women who met weight guidelines, according to a study by Stettler
and colleagues published in 2008 in the American Journal of Clinical
Nutrition.
"What we find is that these things set up children for a lifelong risk
of obesity," says Asheley Cockrell Skinner, an assistant professor of
pediatrics at the University of North Carolina School of Medicine.
"These factors don't just make them overweight; they become barriers to
helping them change when they get older. It becomes the story that never
ends."
Infancy
A newborn's weight is noted on birth announcements, memorialized on the
first page of the baby book and never forgotten by his or her mother.
But perhaps it's a baby's weight at age 1 that matters more, experts
say. Weight that is too high for the child's height — for example, being
at the 75th percentile for weight but the 30th percentile for height —
can spell trouble. Another study from Taveras' research group, published
last year in Pediatrics, found that rapid increases in
weight-for-length measurements during the first six months of life were
associated with a greatly increased risk of obesity at age 3.
No one is sure why rapid weight gain in the first year is important. It
could be that when a baby is fed more than it needs, the brain's
development is affected so that it signals the need for excessive
amounts of food, Stettler says. Likewise, too much food might program an
infant's pancreas, and the body's response to insulin, in a manner that
leads to obesity.
Whatever the cause, Taveras says, "excessive weight gain in those first
six months of life is not baby fat that is going to go away. We're going
to have to change perceptions about what's healthy and what's not
healthy."
Whether a baby is breast-fed (and for how long) or bottle-fed, when it
begins eating solid food and how much it sleeps have also been linked to
obesity risk. A 2008 study in the Archives of Pediatrics &
Adolescent Medicine found that babies in child-care centers or cared for
by relatives tended to have lower rates of being breast-fed and had
solid foods introduced earlier, both factors tied to weight gain.
But studies on breast-feeding are an example of a weakness in the
argument that the early years influence future weight, Stettler says.
For example, one study randomly assigned the mothers of infants to a
program that encouraged breast-feeding and compared them with women who
did not receive the breast-feeding promotion program. More babies were
indeed breast-fed in the first group. But when the children in both
groups reached age 6, there were no differences in their weight. The
paper was published in 2007 in the American Journal of Clinical
Nutrition.
"We know that families that choose to breast-feed are very different
from families that do not," Stettler said. They may have higher incomes
or feed their children more healthful food. Thus, it's hard to say
whether breast-feeding or other family characteristics affect a child's
future risk of obesity.
That's why, Stettler says, "these associations are not ready for prime
time or to be converted into public health recommendations."
Early childhood
Other experts say the soaring rates of child obesity warrant changes
even without solid evidence.
In a study published recently in Pediatrics, Skinner's team found that
obese children as young as age 3 had higher levels of C-reactive
protein, a marker for inflammation that is linked to heart disease in
adults. C-reactive protein levels can rise for a number of reasons, and
about 15% to 20% of children have above-normal levels. But among obese
3-year-olds, 45% had elevated levels. It's not clear yet whether this
inflammation remains high in obese children or causes any long-lasting
harm.
"That indicates to me that when we see what appears to be a chubby kid
on the outside, there may be something different on the inside, compared
with healthy kids," she says. "It's a red flag that something is not
quite right."
Levin didn't wait for someone to test her daughter's C-reactive protein.
The first-time mom recently consulted a doctor who specializes in weight
and nutrition issues, and she learned that the family needed to make
immediate changes. A toddler doesn't need a whole bagel with cream
cheese and salmon for lunch, she learned. One-quarter of that bagel
sandwich would suffice. Low-fat milk is more healthful than whole milk.
Snacks need not include juice.
That doesn't mean she put her child on a diet; most doctors discourage
such restrictions. "It's not about losing weight," says Levin. "It's
about her growing into her weight. We're not focused on numbers and the
scale and all of that. We just need to focus on healthy choices."
More parents of young children are asking for advice on weight and
nutrition, says Dr. Elaine L. Rosen, director of the California Center
for Healthy Living in Encino, where Levin took her daughter. A
pediatrician, Rosen opened her center, which addresses weight or
nutritional problems in babies through young adults, because of high
rates of child obesity and because worried parents didn't know how to
help their kids.
Too much concern on the part of parents can backfire, Rosen says,
leading to eating disorders in children or contributing to children
being overweight or underweight.
"There is a lot of misinformation out there," she says. "A lot of adults
rely on diet-mentality notions, which is not appropriate for kids."
Families are taught what, when and where to feed their children, while
leaving the questions of whether to eat and how much to eat to the
child, Rosen says.
"Sometimes parents cross the line into the domain of control," she says.
"The child does not learn to trust themselves to feed themselves
properly. Some kids resort to under-eating and picky eating. Some
overeat, learn to sneak food and defy their parents."
The emphasis on the early years just makes good sense, Taveras says.
"Almost all of the risk factors we found we can change. We can counsel
families about these issues."
Levin and her daughter began to see Rosen a few months ago. But already,
Levin says, her daughter's preschool teacher has remarked that the
child seems to have had a growth spurt — in height.
A late start
So far, the early years have been ignored when it comes to obesity
practices and policies. First Lady Michelle Obama recently launched a
campaign to address child obesity. But like many other programs, it
focuses on school-age children. There is no organized public-health
effort on obesity prevention from gestation to age 5. The Institute of
Medicine, however, recently convened a task force to study that time
period.
Because child obesity is linked to both maternal and child health,
obstetricians and pediatricians must be enlisted to address obesity
prevention in their patients, Taveras says.
But, she adds, "during pregnancy and the first two years of life,
mothers and their infants are seen by physicians more often than any
other time of life. It's kind of a golden opportunity. We have systems
in place to reach mothers and children."
Source: Los Angeles Times - http://tinyurl.com/yfyonmd