Chilean youth have serious problems with overweight and obesity (World Health Organization, 2014). It is estimated that 41% of students in Chile who entered secondary education in 2015 were overweight or obese (La Nación, 2015). Isolated effects have been obtained in Chilean governmental initiatives. This project constitutes a first theoretical framework that captures teachers' and schools' roles in the institutionalization of anti-obesity messages in Chilean education. At the school level, institutional theory (IT: DiMaggio & Powell, 1983) guided the analysis of the process by which mandatory (law) and nonmandatory (health campaign) anti-obesity messages were taken up in three types of Chilean schools: public schools, state-subsidized private schools, and tuition-supported schools. At the personal level, teachers' intentions to include anti-obesity messages in their teaching activities were studied using the theory of planned behavior (TPB: Ajzen, 1985). Teachers’ intentions were examined through attitudes, subjective norms, and perceived behavioral control at the TPB level; institutional pressures over messages were also analyzed from the influence of coercive, normative, and mimetic isomorphic pressures from the IT perspective. In this exploratory study, research questions and hypotheses related to the adoption of these types of messages were studied using a sample of 10 Chilean schools via interviews of 17 members of the teachers’ management teams and the application of a questionnaire to 245 school teachers. Findings of content analysis and descriptive data found that norms at the school level do not include healthy eating messages and were not considered at school-level decisions. In addition, survey findings reported that regression results from the percentage of behavioral intention (BI) explained variances considering IT isomorphic pressures and TPB constructs were very high. For the legal message, the best predictors were normative isomorphic forces and attitudes (ATTs) instrumental. Instead, for the campaign message, isomorphic forces had little influence, whereas ATTs experiential and instrumental were better predictors. Projections of these preliminary results have great potential for addressing obesity problems in Chile as well as throughout the world
