Obesity prevention in children and adolescents.

Childhood and adolescent obesity has been increasing in most middle- and high-income countries, and, as with adult obesity, this has been driven by increasingly obesogenic environments, especially the food environment. This constitutes a "market failure," signaling the need for government interventions with policies, programs, and social marketing. Population prevention strategies are critical, and children and adolescents should be the priority populations. Food marketing to children is a central policy issue for governments to address, and comprehensive regulations are needed to provide substantive protection for children. Community-based intervention programs show some real promise in reducing childhood obesity, but the 2 big challenges ahead are to ensure that there is substantial ongoing funding so that the community capacity to promote healthy weights can be scaled up to a national level and to ensure that policies are in place to support these efforts. The social and cultural shifts that support healthy eating and physical activity occur differentially, and special efforts are needed to reduce the socioeconomic gradients associated with childhood obesity. A positive public health approach encompassing environmental, regulatory, sociocultural, and educational strategies offer the best chance of reducing obesity without increasing disordered eating patterns.