An Institute of Medicine report out today makes some ambitious recommendations for physical education requirements in schools, including at least 30 minutes a day of movement during school hours.
In the report, the Institute estimates that just half of school-age children get 60 minutes of daily moderate-to-vigorous activity. They suggest that schools make physical education a core subject and add the movement time through physical education classes, recess breaks, classroom exercises and commutes to and from classes.
Since the passage of the No Child Left Behind Act in 2001, 44 percent of school administrators have reported cutting significant time from "phys ed" classes and recess to devote more time to reading and mathematics in the classroom, according to the Institute of Medicine, a nonprofit that provides public policy research and recommendations.
As the report suggests, giving kids more physical activity seems like a no-brainer to help lower the prevalence of obesity rates in elementary school kids, with the percentage of children ages 6 to 11 years old in the United States who were obese to nearly 18 percent in 2010 from 7 percent in 1980.
But there was very little proof until Wednesday that increasing activity has an effect on childhood obesity.
A study published in the most recent issue of the Journal of Health Economics provided the first evidence that increasing physical education in kindergarten through fifth-grade does, indeed, reduce the chance of obesity, at least for boys.
The Cornell University researchers looked at data from a national registry, the Early Childhood Longitudinal Study, and from states that require minutes spent in physical education to determine whether more gym time translates into lower obesity rates. They found that each additional 60 minutes of physical education time lowered the probability of obesity in fifth-grade boys by 4.8 percent and did so without cutting into academics or harming test scores.
The study found the extra gym had almost no effect on girls' obesity rates.
"What could be happening here is that more time in the gym leads boys to become more active outside of school but girls engage in offsetting behavior like increasing TV watching without spending more time outside of school being active," the study's lead researcher, John Cawely, noted.
The Institute of Medicine report also advocates for increased access to intramural and varsity sports. Despite the recommendation, the effect of afterschool sports on weight is far from clear.
In a recent analysis of 19 studies, no solid connection emerged between obesity rates and afterschool sports participation. While a few of the studies noted some small improvements in body weight in some, but not all, kid athletes, other studies found no differences in body weight at all.
One study in the analysis found that fewer than 25 percent of kids who participated in soccer, baseball and softball leagues met recommended levels of activity during their sport team practice. And a few small studies linked sports participation to higher consumption of fast-food that, of course, highlights overconsumption, the other side of the obesity equation.
This last point has not gone unnoticed by parents like Kim Gorman, who say the post-practice junk food ritual is as pervasive in the afterschool sports culture as spiffy uniforms and participation trophies.
Gorman said that when her oldest son Alex, who is now 16, began playing soccer at age 3, she was appalled to find the typical team treat consisted of a juice box and cupcake.