March 10, 2005 -- Kids whose weight is on the high side of normal may need a little extra help to avoid obesity later in life.
Research has already shown that overweight and obese kids are more likely to have weight problems as adults. Now, a new study suggests that kids who are in the upper end of the normal weight range could also be at risk.
"It's important to not just wait [until kids become overweight or obese]," says Alison Field, ScD, assistant professor of pediatrics at Harvard Medical School and Children's Hospital Boston. "Think about it at an earlier stage," she tells WebMD.
"The message really is for clinicians and parents," she continues. Doctors and parents may want to "think more broadly" about a child's weight, even when it's still in the normal range, she says.
For instance, "if a child is in the 50th percentile, then the 65th the next year, then the 75th, that should be a message to the clinician and the parent to think, 'What can we do to stop the excessive weight gain?'" says Field. "Think about prevention at younger ages."
Overweight kids and teens are more than twice as common as they were 20 years ago, says Field's study. About 30% of teens are overweight or at risk for overweight, says the study, citing government figures from 1999-2000.
Fields offers this advice:
- See a doctor. Get expert advice to make sure kids' special dietary needs are met. Encourage activity. "It will help burn more calories and hopefully make kids more body confident, as well," says Field.
- Limit portion sizes. For instance, order a medium or small size when eating out.
- Eat at home more often. It's easier to control portions (and ingredients) when you're dishing out the food.
- Don't single children out. Instead, make healthy eating and activity a family project.
Along those lines, parents may not want to emphasize weight when helping kids build a healthy lifestyle, says Field. Making the changes fun, seamless, and lasting might work better than presenting them as a chore required by numbers on a scale.
Field and colleagues studied 314 Boston-area children. The kids' weight, height, and blood pressure were noted when they were about 11 years old, on average. A follow-up screening was done eight to 12 years later, when the kids were young adults.
Nearly half of the boys (48%) and a quarter of the girls (about 24%) became overweight or obese between the two visits. Those with a higher -- but still normal -- childhood BMI (body mass index) were more likely to become overweight adults. BMI is a measure of weight based on height. Doctors have charts they use to determine if a child falls in the normal range.
"Being in the upper one-half of the normal weight range (i.e. BMI between the 50th and 84th percentiles for age and sex in childhood) was a good predictor of becoming overweight as a young adult," write the researchers.
For instance, girls and boys between the 50th and 74th percentile for BMI were about five times more likely to become overweight compared with their peers below the 50th BMI percentile.
Those who were heavier -- between the 75th and 84th percentiles -- were up to 20 times more likely to become overweight young adults. That's in comparison with kids at the bottom half of normal BMI range.
When it came to blood pressure, more young men than women had problems. High blood pressure occurred in 12% of the young men compared with about 2% of women.
High blood pressure was more common among young men who had been on the heavier side of normal as children.
High blood pressure was four times more likely for boys between the 75th and 85th percentiles for childhood BMI compared to those with childhood BMI below the 75th percentile.
By the same comparison, boys above the 85th BMI percentile were five times more likely to have high blood pressure as young adults.
Few young women in the study had high blood pressure, so there weren't enough data to show a similar trend for girls.
"We did find a large gender difference," says Field. "I think that's a function of how much more weight the boys gained. It's not as though girls are immune [to high blood pressure]."
The study appears in the January issue of Obesity Research.