Kohl called on countries -- low, middle and high-income -- to work across disciplines to fix this problem.

"Physical inactivity is an issue that crosses many sectors and will require collaboration, coordination and communication with multiple partners," he wrote, citing specifically city and community planners, transportation engineers, schools, parks and recreation officials and the media.

He says that almost 75 percent of World Health Organization member countries have some sort of plan to improve physical activity, but only 55 percent of the plans have been put into effect and only 42 percent of the plans in effect are well-funded.

"Substantial improvements in the infrastructure of planning and policy, leadership and advocacy, workforce training and surveillance must be realized," he said.