Exercise, food choices impact childhood obesity

Q. I am concerned because the youngest of my two children is overweight. He just turned 12 and slowly started gaining weight a number of months ago. My husband and I are in shape, we remain active and still play and go for family walks with our dogs. We don't want to act like something is wrong, but at what point do we say something, or, even more important, when is it time to act? His habits are normal, but he is not athletic, choosing to focus on schoolwork, his computer and the television. His older brother was more or less the same way but did not experience this type of gain.

We want to limit television and videogame time, but we're unsure whether time spent on the computer is to be considered the same as time spent in front of the television, seeing as there are no food advertisements.

Name withheld by request

A. Every child is different, and it is normal for children to go through periods where they carry a little extra weight. These tend to precede a growth spurt and are not indicative of a long-term problem. The act of growing takes considerable energy, and the body tends to amass energy resources (body fat) prior to its construction projects. A discussion with your family physician to discuss how your child has been growing in relation to his entire peer group (not only your other son) may assuage your concerns.

I understand your concerns. Childhood obesity has reached near-epidemic proportions in this country. We know that it is only when extra weight stays on for several months or years that the odds increase of an individual remaining obese. Only 14 percent of obese infants remain obese as adults, but this number rises to 40 percent for obese 7 year olds, and 70 percent for obese preteens. Remember, these are only odds, not certainties.

Although the tendency toward obesity (being at least 20 percent over ideal body weight) is inherited, genetics is not the sole cause. Activity patterns and food choices are also a part of the picture. Your comments about television and computer time are on point, and there are two recent studies of note.

The Journal of Pediatrics, in its April 2008 issue, reported on children between 7 and 12, examining the relative influences of physical activity and screen time (television/computer/videogames). Physical activity was assessed using a pedometer, and screen time was tallied using a survey. A total of 709 children participated, and their activity and screen time were compared with the standards of the American Academy of Pediatrics.

The AAP has recommended that boys should take at least 13,000 steps a day and girls should take at least 11,000 steps a day. These activity levels are coupled with the advisory that children should limit total screen time to two hours per day. Almost 20 percent of the children surveyed in the study were found to be overweight, with less than half meeting both recommendations of the AAP.

As expected, the study reported that those not meeting the guidelines were three to four times more likely to be overweight.

The March 2008 issue of Archives of Pediatric & Adolescent Medicine looked at overweight children between the ages of 4 and 7 who logged at least 14 hours per week watching television and playing computer games. The study subjected half to an intervention that reduced television/computer time by 50 percent using a special device (TV Allowance), while giving the children control over how they spent their time. At the end of the two-year study, BMI went down in the intervention group. The effect was particularly significant in children of lower socioeconomic class -- an important finding, as this a group that is at higher risk for obesity.

Let me state again that every child has his or her own unique growth timetable. Healthful habits, which includes diet and activity, are the key. A good parental example is priceless. Children can transition in and out of being overweight and still be healthy, so it pays to encourage them to maintain the right stuff in their young lives. These habits will help maximize their health potential and become part of their lifestyle as they transition into adulthood.