I can comment on that a little bit.
If you look at the interventions that were included or examined by the Cochrane review, it could be that the interventions weren't sufficiently intense for the changes in behaviour to lead to the changes in body composition that we would hope to achieve. If you look at the number of dollars that are invested in a lot of school-based interventions in the community, health promotion doesn't get a lot of money. If you look at the billions and billions of dollars that marketing companies have to market these foods to little children and parents, I think that's something we need to look at, because the local-level interventions need to be supported by broader-level policies that are supported by the government.
Also, we did see some changes in the Kahnawake schools diabetes prevention project, in increased physical activity around 1999. In 2004 we lost that effect, and it could be because the number of physical activity minutes in the schools dropped. So there are changes that could be made. While teachers and school administrators are trying to uphold academic standards, at the same time they have to address physical activity and health education. Changes could be made within the school system by mandating a minimum number of physical activity minutes.