|Overweight in Early Childhood Increases Chances
for Obesity at Age 12
Children who are overweight as toddlers or preschoolers are more
likely to be overweight or obese in early adolescence, report researchers
in a collaborative study by the NIH and several academic institutions.
The researchers periodically collected height and weight measurements
of a sample of children, beginning at age 2 and continuing until
age 12. Their analysis, appearing in the September Pediatrics,
provides some of the strongest evidence to date that overweight
in early childhood increase the chances for overweight in later
“These findings underscore the need to maintain a healthy weight
beginning in early childhood,” said Duane Alexander, M.D., the
Director of NIH’s National Institute of Child Health and Human
Development, which funded the study. “Contrary to popular belief,
young children who are overweight or obese typically won’t lose
the extra weight simply as a result of getting older.”
A large number of studies have found that obesity persists from
childhood, through adolescence and into adulthood. Obese adolescents
are likely to become overweight adults and, as such, at risk for
the complications of obesity — cardiovascular disease, high
blood pressure, stroke, and diabetes.
Most previous studies have collected height and weight information
only from a few intervals in childhood and 1 or 2 intervals in
later life. The strength of the current analysis is that it was
conducted on data collected during frequent intervals over an extended
period of time, from age 2 through age 12, explained the study’s
principal investigator, Philip R. Nader, M.D., Professor Emeritus
of Pediatrics at the University of California, San Diego, School
of Medicine. Dr. Nader added that the children who took part in
the study were born in 1991, and so were growing up during the
current trend of overweight and obesity in the general population.
The analysis was conducted on data collected as part of the NICHD
Study of Early Child Care and Youth Development. For the study,
researchers followed the development of more than 1000 children
from across the United States, enrolled in the study at birth.
Although the study sample was not nationally representative of
the United States as a whole, the sample did include children from
ethnically diverse and economically disadvantaged households. More
than 80 percent of the children in the study grew up in two-parent
families. For the most part, the study focused on gathering information
relevant to children’s experience in various child care arrangements.
However, measurements of the children’s height and weight were
collected when the children were ages 2, 3, 4 ½, 7, 9, 11, and
For the current analysis, the researchers calculated body mass
index, or BMI, for children in the study. BMI is a standard measure
calculated from an individual’s height and weight. Children were
classified as overweight if their BMI was at or above the 85th
percentile in comparison to national statistics for children their
The researchers found that children who were overweight at least
once from ages 2 to 4 ½ were 5 times more likely to be overweight
at age 12 when compared to children who were not overweight from
ages 2 to 4 ½. The more times a child was overweight from ages
7 through 11, the greater the chances the child would be overweight
at age 12 in comparison to children who were not overweight from
ages 7 through 11. For example, a child who was overweight once
during the elementary school years was 25 times more likely to
be overweight at age 12 than was a child who was not overweight
during the elementary school period. Similarly, when compared to
children who were not overweight, children who were overweight
twice during the elementary period were 159 times more likely to
be overweight at 12, and children overweight 3 times during elementary
school were 374 times more likely to be overweight at 12.
Dr. Nader said that the study results strongly suggest that parents
concerned about their children’s weight should speak to their children’s
pediatricians about helping their children establish more healthful
diet and exercise patterns. Because pediatricians regularly measure
their patients’ height and weight, Dr. Nader added, they are in
an excellent position to proactively advise parents if they see
signs of unhealthful weight gain.
“Pediatricians can be confident in counseling parents to begin
to address the at-risk child’s eating and activity patterns rather
than delaying in hopes that overweight and the patterns that support
it will resolve themselves in due course,” the study authors wrote. “Identifying
children at risk for adolescent obesity provides physicians with
an opportunity for earlier intervention with the goal of limiting
the progression of abnormal weight gain that results in the development
of obesity-related morbidity.”
The researchers also reported some risk of overweight at age 12
for children who were not overweight during the preschool and elementary
years but had still had relatively higher BMIs at those ages. For
example, 4 ½ year old children with BMIs between the 50th and 75th
percentile were 4 times more likely to be overweight at age 12
than were children below the 50th percentile at age 4 ½.
Children in these percentiles were within the range of normal
weight, Dr. Nader noted, and so do not need a weight management
regimen. Still, given the study findings that preschool and elementary
age children with BMIs between the 50th and 75th percentile are
at risk for overweight at age 12, it would be advisable for parents
and physicians to observe children in this BMI range and to begin
corrective action if the children’s weight edges upward.
The study authors also found that no children in the study who
were below the 50th percentile at preschool or elementary school
age were overweight at age 12.
Information about the NICHD Study of Early Child Care and Youth
Development is available at http://www.nichd.nih.gov/od/secc/index.htm.
The NICHD sponsors research on development, before and after
birth; maternal, child, and family health; reproductive biology
and population issues; and medical rehabilitation. For more information,
visit the Institute’s Web site at http://www.nichd.nih.gov/.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.