America’s babies are chubbier than they used to be, according to a new study.

The study found a 74 percent jump in babies newborn to 6 months who are overweight, and a 59 percent rise in babies at risk of becoming overweight.

The estimates are based on information about 120,000 kids up to 6 years old at a Massachusetts health maintenance organization (HMO) between 1980 and 2001.

“The obesity epidemic has spared no age group, even our youngest children,” researcher Matthew Gilman, MD, says in a Harvard news release.

Gilman is an associate professor at Harvard Medical School’s ambulatory care and prevention department. He also works at Harvard Pilgrim Health Care.

The study appears in the July issue of Obesity.

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The children’s height and weight were recorded at doctor’s visits.

Babies and kids typically see doctors fairly often for routine checkups. The researchers noted only one set of measurements for each child per year, to avoid skewing the data.

Here are the results for kids younger than 6 years, including babies:

--Overweight prevalence rose from 6.3 percent to 10 percent

--Prevalence of being at-risk-of-overweight increased from about 11 percent to 14 percent.

--Looking specifically at infants up to 6 months of age, in 1980-1981, 3.4 percent were overweight, and about 7 percent were at risk of becoming overweight.

Twenty years later, 5.9 percent of the babies were overweight, and 11.1 percent were at risk of becoming overweight.

“Our data demonstrate that overweight is increasing in very young children, including infants,” the researchers write.

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Lasting Effects?

The study doesn’t indicate whether overweight babies became overweight teens and adults, or if they were healthy – just a little hefty.

But other studies have shown that extra pounds often stick around from childhood into adulthood, the researchers note.

Gilman says “efforts to prevent obesity must start at the earliest stages of human development, even before birth.”

His recommendations:

Don’t smoke or gain too much weight during pregnancy Take steps to prevent gestational diabetes Breastfeed your baby

Those steps have been shown to give kids a head start to healthy weight, Gilman notes.

A certain amount of “baby fat” is normal. If you’re concerned about your child’s weight, ask your child’s pediatrician for advice.

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By Miranda Hitti, reviewed by Louise Chang, MD

SOURCES: Kim, J. Obesity, July 2006; vol 14. News release, Harvard Medical School.