Preventing childhood obesity in Latin America: linking evidence to policy and practice

Objectives: Childhood obesity is an epidemic of major proportions in Latin America, its causes are multifactorial that are the result of complex interactions across and within systems operating at different levels of the social-ecological model. Thus, an important step needed to effectively address this epidemic is to develop a web of evidence-based policies capable of changing the environmental defaults needed for families to implement the recommended healthy lifestyles including diet and physical activity. The objective of this presentation is to illustrate the process of translation of research into key obesity prevention policies based on a case study methodology. b) Development Three case studies directly relevant to childhood obesity were developed to illustrate the process of development of the soda and junk food tax policy in Mexico (Rivera), food label legislation in Chile (Corvalan), and the use of open public spaces for physical activity in the Americas (Jacoby). Mexico passed its national tax legislation in 2013 and started implementing it in 2014. This policy targets all sweetened water-based (non-alcoholic) beverages and junk food (per a high energy density criteria) sold to the general public. This policy was strongly backed up by the latest scientific evidence and its passing involved strong engagement and legislative evidence-based advocacy from civil society against a backdrop of negative loops created by the food industry with the media playing a strong role presenting the arguments from both sides. Its feasibility was assessed by the ministry of finance who concluded that this approach could indeed generate revenue that could be invested to advance public health (i.e., a highly popular win-win proposition). The implementation of this policy has not been without challenges including a highly iterative process to operationalize the definition of “junk food”. This taxation policy has generated hundreds of millions of dollars in 2014 alone. However, its impact in obesity rates remains to be determined. In 2012, Chile passed the National Law of Food Labeling and Advertising to promote healthy diets and address the obesity and related chronic diseases epidemics. The law focuses on point-of-food purchase labeling and specific messaging around sugar, saturated fats, sodium, and energy. It also includes restrictions on marketing and selling unhealthy foods to children. The successful passing of the final modified law has been explained, at least in part, by the evidence based advocacy upon which it was built, the strong academic-policy maker partnership with highly respected political champions, strong negotiations among a diverse group of key stakeholders including political parties, the Chilean Ministry of Health, and the food industry. Reaching consensus on the regulatory code needed to guide labeling has been a major challenge also characterized by a complex interplay among stakeholders requiring overcoming negative feedback loops that have had strong input from the food industry. The impact of this policy remains to be determined. The use of ciclovias (CVs) or motorized vehicle-free open public spaces where physical activities such as walking, jogging, and biking can be safely performed started in Bogotá, Colombia in the 70s and by 2013 there were more than 350 cities with CVs in Latin America. This spectacular growth has been attributed to the reaction from civil society to life in car-centered highly congested urban areas coupled with strong political will driven in part by how popular CVs are in the population at large and also based on cost-effectiveness research findings driven by the burden of disease prevented through higher levels of physical activity. Successful implementation of CVs requires establishing complex government-private-sector-civil society alliance capable of overcoming the strong negative feedback loops generated by stakeholders who perceive their interests will be affected by the CVs. Conclusions: An integration of results from the 3 case studies analyzed integrating findings form successful implementation of policies that are likely to impact childhood obesity shows that each example operates as complex adaptive system where evidence based advocacy from civil society (with strong involvement from champions in the academic sector), political will, and skillful negotiations across key sectors including government and the private sector to overcome strong negative feedback loops. These findings are highly consistent with what has been observed in other nutrition-related policy case studies including breastfeeding promotion, protection, and support (Pérez-Escamilla) and the removal of trans-fats from processed foods in Argentina, the result of a complex evidence-based driven multisectoral process involving food product reformulation legislation (Rubinstein). Being successful at passing and launching national policies to address the childhood obesity epidemic is a necessary but not sufficient condition to enact change. As the soda/junk food tax in Mexico and the food label legislation in Chile highlight articulating the policies into concrete actions represents another sets of challenges that need to be overcome for their successful implementation. Key words Evidence-based policies, obesity, public nutrition, systems thinking, implementation science.