"A lot of parents and pediatricians still tend to say, 'Oh, it's just baby fat.' This study shows that really isn't necessarily the case," says Dr. Jim Griffin of the U.S. National Institute of Child Health and Human Development. "It's not predestination, but the odds are that the child who is overweight -- and significantly overweight -- in that period will continue to be overweight."
The report was based on a day care study of over 1,000 healthy U.S. children in 10 locations across the nation, most of whom were from financially "well-off" families and born in 1991, when experts say the current obesity epidemic started gathering steam.
The body mass index (BMI) of each child was measured periodically, and they were classified as overweight if the BMI reached or exceeded the 85th percentile, or within the top 15 percent of their age group.
That classification means a 7-year-old weighing as little as 4 pounds more than their average peer was classified as overweight. Even though 4 pounds isn't much, lead author Dr. Philip Nader, professor emeritus at the University of California, San Diego, says it's part of the cumulative effect of continuous weight gain.
"The closer you get to adolescence, the less likely it is to be able to shed that extra weight," he said.
According to the study, 60 percent of the participants who were overweight at any time during preschool years were overweight by age 12, and 80 percent of kids who were overweight even once during their elementary years were also overweight by age 12. Preschoolers whose BMI was above the 50th percentile were six times more likely to be overweight when they reached adolescence.
"These findings suggest that parents and health care providers may want to be even more vigilant than currently recommended in recognizing early signs of being on the path to overweight," the researchers reported.