U.S. kids take 3,000 fewer steps per day than the Swedish
As overweight customers threaten lawsuits against fast-food icon McDonald's and the government requires that processed-food manufacturers like Kraft report unhealthy trans fat content, a new study led by a Brigham Young University researcher says that American children are fatter and less active than peers in similarly developed countries.
Susan Vincent, a BYU professor of physical fitness and lead author on the study, says the average American child takes about 1,000 fewer steps per day than an Australian child and about 3,000 fewer than a Swedish child. American children also have a significantly higher body mass index value, a measurement of height relative to weight, than Australian and Swedish children.
"Their culture and communities are set up differently from America's," says Vincent, who reports her findings in the new issue of the journal "Medicine & Science In Sports & Exercise." "We tend to drive everywhere instead of walking or riding bicycles."
That said, the average American child still engages in enough physical activity to merit an award from the President's Council on Physical Fitness and Sports. Vincent estimates the amount of time American children spend at the playground may have decreased over the years, but not by much.
"If you compare children with adolescents and adults, children still constitute our most active group," says Vincent. "Inactivity isn't the reason behind childhood obesity, but it's definitely part of the puzzle. With rising obesity levels, we need to encourage fitness among children."
One such attempt by the PCPFS is the newly created Presidential Active Lifestyle Award. Administered by teachers through schools nationwide, the program recognizes children and youth who participate in daily physical activity of any type five days a week, 60 minutes a day or 11,000 (for girls) to 13,000 (for boys) steps a day for six weeks.
"That's an encouraging fact, to know that most kids are getting at least that much activity," says Vincent. "Individually, however, that may not be the case. It's those kids who are pulling the average down that we're most concerned about."
The study reports data gathered from nearly 2,000 elementary school children in America, Australia and Sweden. Participants wore pedometers, electronic instruments sensitive to body motion, to record the number of steps they took each day. Body mass index was also taken for each child.
For boys, the average number of daily steps taken ranged from about 12,550 to 13,900 for America; 13,900 to 15,000 for Australia and 15,700 to 18,350 for Sweden. For girls, the average step counts ranged from about 10,700 to 11,400 for America; 11,200 to 12,300 for Australia and 12,050 to 14,800 for Sweden.
Charles Corbin, a professor from Arizona State University-East's Department of Exercise and Wellness, says the study is one of the few to provide information for both physical activity and body mass index.
"This well controlled study provides us with very interesting baseline data describing the activity and body mass index patterns of youth in three different countries. Because the study identifies both activity and body mass index patterns, relationships between the two variables can be examined," says Corbin. "While relationships between activity patterns and BMI are not especially high, the fact that the most active groups had low BMI levels is important."
Researchers were surprised to learn that activity levels remained fairly constant from 6 to 12 years of age, a finding that could provide insight into when humans become less active.
"Going into the study, we all knew that there was a point at which people stopped getting as much exercise as they used to get. Current research supports this, but no real cutoff age has been determined," says Vincent. "The data we gathered shows that the slowdown is not happening by age 12."
Future studies by Vincent and her collaborators will look at adolescent activity levels, hopefully providing the age at which children limit playing neighborhood games and start focusing on video games.
"Also, we didn't measure nutrition in this study, and that plays a large role in obesity levels," says Vincent. "The study that targets adolescents will examine the role of nutrition as an obesity indicator."
In the meantime, Vincent suggests parents take steps to encourage greater activity among their kids.
"Television and computer time needs to be monitored," says Vincent. "A little of that isn't harmful. But spending hours in front of a screen instead of out in the neighborhood isn't good for you." Finally, Vincent says, that will help only if parents get involved in their children's playtime.
"Parents should show that they care about the benefits of fitness by setting an example of engaging in regular, physical activity."