Childhood Obesity and School Exercise Programs: Not So Fast

I hate to pour cold water on what seems like a surefire way to combat childhood obesity—namely, school-based health and exercise programs—so I’ll blame the Cochrane Collaboration for doing so. This non-profit group of scientists and physicians, based in England, regularly assesses the weight of the evidence on health and medical questions from whether St. John’s wort can alleviate depression (yes, sort of) to whether mouthwash can reduce bad breath (in some cases). Now the Cochrane team has weighed in on whether school programs can help kids lose weight.

That’s a little discouraging, given the renewed emphasis on using schools to combat the growing incidence of childhood obesity and its attendant diabetes. Studies from Greece to England to Australia and beyond have looked for correlations between physical inactivity and obesity, or school-based exercise programs and health benefits, calling almost unanimously for (to pick just one) “necessary school interventions in order to encourage healthier behaviours and habits.” To be sure, school-based programs here and there have reported success in reducing obesity and fostering healthy habits, but the results tend to be equivocal, especially when it comes to getting kids to stick with the program.

Taken together, the 26 studies of school-based programs aimed at promoting physical activity in Australia, South America, Europe and North America which the Cochrane team examined increased how long children spend exercising and cut their TV-watching time. So far, so good. The programs also reduced blood cholesterol levels and improved lung capacity, a measure of fitness. But—now the bad news—the programs had little effect on weight or blood pressure or on what kids choose to do in their free time, the last being a crucial indication of whether the programs are likely to change lifestyle habits for the better.

“Given that there are at least some beneficial effects, we would recommend that schools continue their health promotion programs,” said Maureen Dobbins of the School of Nursing at McMaster University in Ontario, who led the review.

But why didn’t the programs do what public health officials hope, namely take off pounds and instill lifelong healthy habits? “Physical activity classes may be too closely associated with school work, so for some students this makes them feel like they are being made to do more work,” says Dobbins. In that case, the last thing kids want to do is more such “work” on their own time, when a teacher isn’t making them. Kind of like if you make reading a chore for kids, they think of it that way—and never want to pick up another book unless they have to.