Heavy kindergarteners more likely to be obese later in life

A child who is heavy as a 5-year-old is more likely to be overweight or obese in middle school, found a study published Thursday in The New England Journal of Medicine. And propensity toward obesity may be set even earlier in life, according to researchers at Emory University who tracked the weight of 7,700 children from kindergarten through eighth grade.

“This study underscores the fact that being overweight and obese are life-long concerns,” said Dr. Anne McTiernan, a Fred Hutchinson researcher who studies the role of exercise in cancer prevention and was not involved in the study.

When the children in the study entered kindergarten, almost 15 percent were overweight with body mass indices (BMI) above the 85th percentile, and 12 percent had BMIs above the 95th percentile and were obese. But by the time that the kids reached eighth grade, 17 percent of children were overweight and more than 20 percent were obese.  The researchers found that of those children who became obese between the ages of 5 and 14 years, almost 50 percent had been overweight kindergarteners, and three-quarters had been above the 70th percentile for body max index.

The study suggests that factors influencing weight begin exerting their influence even before kindergarten. Children with high birth weights were much more likely than average or underweight babies to become obese.

Researchers speculate that early interventions—even prior to kindergarten—will be critical to preventing childhood obesity. So far, tackling the problem in school-age children has had little effect.

“[The findings] suggest that maybe one reason it didn’t work so well is that by the time kids are 5, the horse is out of the barn,” Leann L. Birch, a professor in the department of foods and nutrition at the University of Georgia, who was not involved with the study, told The New York Times.

Dr. Linda Ko, a public health researcher at Fred Hutch who focuses on childhood obesity, suggests that the answer might be tied to a multi-pronged approach.

“There are many powerful external forces that can influence children’s behavior such as friends and family, types of food choices in schools and lack of opportunities to be active in school or in their community, and on top of that, daily influx of food products by media and advertisements,” observed Ko.

Better access to fresh fruits and vegetables and opportunities to be physically active, such as walking paths, could help address factors promoting obesity in children, Ko speculated. “In addition, health policies are needed to help shift the paradigm from treatment to prevention, so that organizations providing healthcare receive support and funding for obesity prevention programs, and insurance companies are able to reward their clients’ healthy behaviors.”

Bad habits developed early in life like a sedentary lifestyle and poor diet, will have a cumulative effect on weight, especially if established early in life, explained McTiernan. But the news is not dire.

“The good news is that people can change habits and can lose weight even later in life,” McTiernan noted, and her own work has demonstrated that even older adults in their 40s through 70s can make lifestyle changes in exercise and diet that improve their weight, health, and cancer risk.

Reach writer Sabrina Richards at srichar2@fhcrc.org.

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