When baby fat is no longer cute
"Look at those chubby cheeks!" For centuries, mothers have rejoiced over pudgy babies and fretted over those who failed to plump up. Those fears are justified. Babies who don't gain weight often have significant health problems, and the condition even has a medical diagnosis: "failure to thrive." Now, with childhood obesity a growing health concern–17 percent of American kids are obese, compared with 7 percent in 1980–researchers are trying to figure out when healthy chubbiness becomes unhealthy fat. Fat kids, the scientists say, are far more likely to become fat adults, with a far greater risk of heart disease, diabetes, and other major diseases. But how fat is too fat?
Not all that fat, it turns out. An average-size 3-year-old would have to weigh just 4 pounds more, or 36 pounds instead of 32, to be five times more likely to be overweight at age 12. That startling fact was gleaned from a survey that followed 1,042 healthy children born in 1991 through childhood. Researchers funded by the National Institute of Child and Health Development compared data on the kids' weight at key developmental stages, from 2 to 12 years. It's the best look to date at the origins of childhood obesity.
The kids who were fat early on in life were far more likely to be fat 12-year-olds than those who were not overweight as preschoolers. Sixty percent of the children who were overweight at any time during the preschool years, and 80 percent of those overweight at any time in elementary school, were overweight at age 12. Overweight was defined as a body-mass index (BMI) in at least the 85th percentile compared with national statistics for children that age.
"The good news is that there's time to prevent this snowball effect of gathering weight slowly over time," says Philip Nader, an emeritus professor of pediatrics at the University of California–San Diego, who led the study, published in September's Pediatrics. "If I were a parent of a 3- or 4-year-old at risk, I wouldn't panic and put the kid on a diet." Rather, Nader says, look at the child's environment. Are there healthy snacks available, like apples and carrots? "One mother told me, 'If you cut it, they will eat it.' And they do."
Another simple fat-fighting act: Turn off the TV and the computer, and send the kids outside. "There's a lot of evidence suggesting that more than a couple of hours of screen time a day is associated with overweight," Nader says.
Nader's advice is backed by the Institute of Medicine, which this week reported that the nation is starting to make progress on programs to reduce childhood obesity–but just barely. "Americans have begun to recognize that childhood obesity is a serious public health problem," says Jeffrey Koplan, a former director of the Centers for Disease Control and Prevention who led the IOM investigation. Some federal policies have been changed to encourage healthier school lunches and physical activity in schools, the report noted. And some communities are installing sidewalks and bike paths so kids can walk to school.
But in too many communities, the IOM report says, children don't have a safe place to play outside, either because their suburban streets lack sidewalks or because the neighborhood park is too dangerous.
For the past thousand years, the human life span has grown steadily longer. If progress doesn't speed up, that rise in longevity may end, researchers say, within the next 50 years. And children growing up now may have shorter lives than their parents.
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