With Young Children, Overweight Should Be Nipped in the Bud

ROCKVILLE, Md., Sept. 7 -- Watchful waiting when faced with overweight preschoolers and elementary school children is poor pediatric practice.

So concluded a longitudinal study of more than 1,000 U.S. children by the National Institute of Child Health and Human Development Early Child Care Research Network.

Instead, pediatricians and others should immediately prescribe exercise and improved diet, rather than waiting in the hope that the children's weight will normalize as they grow older, said the investigators.

The longer young children remained overweight, the more likely they were to still be overweight in early adolescence, found the researchers, headed by Philip. R. Nader, M.D., of the University of California San Diego.

"Pediatricians and other health care providers seeing children are currently faced with a dilemma," Dr. Nader and colleagues wrote in the September issue of Pediatrics. "Although the short- and long-range detrimental outcomes of overweight in children and adolescents are evident, no clear criteria exist for identifying who or when a child may be at risk for later obesity."

Physicians have no firm guidelines about when to intervene or clear evidence that successfully reducing excess weight in young children will reduce risk for overweight later in life, the investigators said.

"As a result, pediatricians may be inclined not to pursue growth indicators of obesity or overweight status, at least in part because anecdotal experience and uncertainty regarding effectiveness may suggest that watchful waiting is a more prudent course of action," they said.

The longitudinal study, however, suggests otherwise, they said. It included 1,042 healthy children from 10 U.S. locations who were born in 1991. The researchers measured these children's height and weight at seven points, including three times in preschool at ages two, three, and four-and-a-half; three times in elementary school at ages seven, nine, and 11; and once at age 12.

Compared with those who were never overweight (below the 85^th percentile for BMI at all 3 of the preschool ages), children who were overweight (BMI in the 85^th percentile or higher) at one or more points during their preschool years were nearly six times more likely to be overweight at age 12 (odds ratio=5.9; 95% confidence interval=3.9 to 8.8), the study found.

The effect was much more pronounced in elementary school children. Kids who were overweight once during elementary school were nearly 26 times more likely to be overweight at age 12 (OR=25.9; 95% CI=12.0 to 55.9). Those overweight at two elementary school time points were nearly 160 times more likely (OR=159.9; 95% CI=57 to 445).

Those overweight at all three time points in elementary school were 374 times more likely to be overweight at age 12 (OR=374; 95% CI=145 to 963).

Sixty percent of children overweight at any time during preschool were still overweight at age 12, as were 80% of those overweight at any time during elementary school, the study found.

Follow-up calculations showed that two in five children whose BMIs were greater than the 50th percentile by age three years were overweight at age 12. No children who were less than the 50th percentile for BMI at all points during elementary school were overweight at age 12 years.

Children who have higher range BMIs earlier, but not at the 85th percentile, are also more likely to be overweight at age 12 years. Even at points before and including age nine, children whose BMIs are between the 75th and 85th percentile have a 40% to 50% chance of being overweight at age 12.

"These results suggest that any time a child reaches the 85^th percentile for BMI may be an appropriate time for intervention," the authors said.

"A minimal intervention approach that promotes healthful eating and activity behaviors, both on an individual and population basis, seems logical," they added.

"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," they said.

Irrespective of whether early weight gain leads to immediate or long-term morbidity is still a matter of debate among pediatricians, as are the potential benefits and costs of routinely screening young children for overweight, the authors said.

"Nevertheless, there is good evidence that absence of overweight is a positive health goal for most individuals and that efforts to reduce overweight need to begin in childhood," they concluded.

Because the study population was largely white and economically well-off, it is not certain that these results would apply to the general population of U.S. children, the authors said.

Another limitation of the study is that it did not take into account the parent's height and weight, which has been linked to overweight and obesity risk in children, the authors said.