Efforts to prevent childhood obesity should begin far
earlier than currently thought — perhaps even before birth — especially for
minority children, according to a new study that tracked 1,826 women from
pregnancy through their children’s first five years of life.
Most obesity prevention programs — including the national
initiative recently launched by first lady Michelle Obama — target kids ages 8
and older. Scientists at the Harvard Pilgrim Health Care Institute’s Department
of Population Medicine, an affiliate of Harvard Medical School(HMS), now say that
factors that place children at higher risk for obesity begin at infancy, and in
some cases, during pregnancy. Their research also suggests that risk factors
such as poor feeding practices, insufficient sleep, and televisions in bedrooms
are more prevalent among minority children than white children.
“This early life period — prenatal, infancy, to age 5 — is a
key period for childhood obesity prevention, especially for minority children,”
says Elsie Taveras, lead author of the study and an assistant professor of
population medicine and of pediatrics at HMS, as well
as the director of the One Step Ahead Program at Children’s Hospital Boston.
“Almost every single risk factor in that period before age 2, including in the
prenatal period, was disproportionately higher among minority children.”
For the study, which appears online today in the journal
Pediatrics, researchers interviewed 1,343 white, 355 black, and 128 Hispanic
pregnant women at the end of the first and second trimesters, in the first few
days following delivery, and when the children were 6 months and 3 years of
age. The women also completed questionnaires when the children were 1, 2, and 4
When compared to Caucasian women, the researchers found that
minority women were more likely to be overweight when they became pregnant and
Hispanic women had a higher rate of gestational diabetes, both risk factors for
childhood obesity. Although the prevalence of two other risk factors — smoking
and depression — during pregnancy was higher among African-American and
Hispanic women, those rates dropped considerably when the researchers adjusted
for socioeconomic status, suggesting that at least those two risk factors may
be impacted by income and education levels.
When researchers looked at other risk factors during
children’s first five years, they found that African-American and Hispanic
infants are more likely than their Caucasian counterparts to be born small,
gain excess weight after birth, begin eating solid foods before 4 months of age,
and sleep less. During their preschool years, the study suggests, minority
children eat more fast food, drink more sugar-sweetened beverages, and are more
likely to have televisions in their rooms than Caucasian children.
One commonly held theory is that the presence of these and
other risk factors is caused by limited access to health care, poverty, and low
educational levels. However, when Taveras and her colleagues adjusted for
socioeconomic status, they found that the prevalence of many of the risk
factors remained the same.
More likely, Taveras says, the risk factors stem from
behaviors and habits passed from generation to generation or that may be
culturally embedded. “For a lot of patients I see in my clinic, it’s
intergenerational—for example, the grandmother in the home is influencing how
her daughter feeds her own child.” That’s especially true when it comes to at
what age mothers begin giving their infants solid food or when the mothers
decide to stop breastfeeding, Taveras says.
“Sometimes trying to tackle those intergenerational
influences can be very difficult, but actually, it’s promising that some of the
areas where we did find disparities are modifiable,” Taveras notes. “Anyone who
works with families of young children, including pediatricians and child-care
providers, can work on these issues.”
The far more difficult task would be to address problems
that are related to socioeconomic status. In this study, that didn’t play as
large a role because participants had access to good prenatal and pediatric
care for their children and were well-educated.
“We found these striking disparities even in this population,
where we had racial and ethnic minority families who were of relatively higher
education and income,” she says. “Imagine what the disparity would be in a
population that’s of lower socioeconomic status.”
That’s a question Taveras plans to tackle next. The goal now
is to look at other novel risk factors that might be more common among minority
populations — including those that will likely be tied to income and education.
“All of the risk factors that we examined in this study were
known factors that have been published in the literature, including some of our
own literatures,” Taveras says. “But there are risk factors that are still
understudied, that we have a sense are more common, and that’s where we plan to
This research was funded by the National Institutes of
Health’s National Center on Minority Health and Health Disparities and the
Robert Wood Johnson Foundation.