The aims is to evaluate the effects of an multidimensional intervention on the physical-built and social environment around schools and the nutritional status of the school population, through a randomized community trial, in schools in 3 states of the Mexican Republic, using anthropometric indicators, biological, psychological, behavioral and environmental.

The main questions it aims to answer are:

1. What are the main risk and protective factors for overweight and obesity in the school environment and in the environments around schools in primary education schools in three states of the Mexican Republic?
2. Is there a relationship between risky eating behaviors and the body mass index of schoolchildren?
3. Are the strategies that are being implemented effective in reducing the presence of risk factors and increasing the presence of protective factors for overweight and obesity in the school environment and in the environments around schools?
4. Are the strategies that are being implemented effective in reducing the presence of risk factors and increasing the protective factors for overweight and obesity in the family environment?

This is a project designed and approved to be carried out in 4 stages. The project has financing from the health sector fund and also an extension to end on January 11, 2025. The objective is to evaluate the effects of a multidimensional intervention (MI) on the physical-built and social environment around schools, as well as, on the nutritional status of the school population, through a community trial in schools in 3 states of the Mexican Republic (Campeche, Mexico City and Morelos). The impact will be measured through anthropometric, biological, psychological, behavioral and environmental indicators. The target population of the intervention will be students between 9-12 years old who are in the 4th grade of primary school.

Stage 1. Situational diagnosis. Duration: 12 months. In the design of health promotion interventions, situational diagnostic assessment is necessary to be able to design an intervention adapted to the context and real needs of the target population. This stage of the project also allows us to identify previous experiences and derive from them available evidence on interventions that have been implemented in other populations. Likewise, it is necessary to identify the health problems of the population to which the intervention to be designed is directed, as well as the existing policies and programs and the participation of the target population to which the intervention to be designed is aimed.

Stage 2. Design and development of the multidimensional intervention and evaluation instruments. Duration: 12 months. The information generated from the situational diagnosis will serve to design the multidimensional intervention of this proposal, which will include different levels of intervention such as school, around school, home and community. The components of this stage are the following: 1) Final design of the multidimensional intervention; and 2) Definition of the components of the multidimensional intervention, which include: a) Actions to ensure a healthy food environment; b) Comprehensive Physical Activity Program; c) Teacher training; d) Motivation of teachers; e) Educational materials with a social marketing focus, short or simple message service (SMS), printed or audiovisual material; f) Implementation logistics; g) Development of instruments necessary for intervention; h) Validation or pilot testing of the intervention materials.

Stage 3. Implementation, monitoring and evaluation of the multidimensional intervention. Duration: 10 months. The final design of the multidimensional intervention that will be implemented during this stage will depend on the modifications made in the stages described above. This stage consists of the following phases: 1) Randomization, 2) Initial evaluation, 3) Beginning of the intervention, 4) Monitoring and evaluation of the process and 5) Final evaluation.

Stage 4. Institutionalization of the intervention. Duration: 12 months. In the final stage, an analysis and formulation of recommendations will be carried out for the escalation and incorporation of the intervention to the Ministry of Public Education (SEP, for its acronym in Spanish).

The study consists of a community trial in 24 schools in 3 states of the Mexican Republic (Campeche, Morelos and Mexico City) and a parallel randomized clinical trial in 4 of the schools in Cuernavaca, Morelos. Both studies together will address the questions raised in the previous section.

Inclusion Criteria:

• Fourth grade elementary schools children from schools that belong to Federal entities: Campeche, Morelos and Mexico City, with morning schedule, from 8:00 to 12:30 or extended schedule, from 8:00 to 14:00hrs.
• For Morelos State, elementary schools will be sought to be private, with at least 1000 enrollement students, with morning schedule, from 8:00 to 12:30 or extended schedule, from 8:00 to 14:00hrs.

Exclusion Criteria:

• Children that don´t correspond to the selected shifts.

girls and boys have similiar proportion

Confidential information

The children who participate are not aware of being a control or intervention group, as well as their parents, teachers and school cooperative staff.