Effectiveness of a School-based Obesity Prevention Program on Body Fat At 6 Months of Mexican Children

Effectiveness of a School-based Obesity Prevention Program on Body Fat At 6 Months of Mexican Children: a Cluster Randomized Controlled Trial

School-based programs are an essential strategy for preventing obesity, yet the most effective way to implement them remains unclear. This study aims to evaluate the effectiveness of a school-based obesity prevention program, delivered by different implementers, in comparison to a control group, focusing on body fat reduction in Mexican children. This is a cluster randomized controlled trial. Approximately six public elementary schools (240 children) in Hermosillo, Mexico, will be invited to participate. Schools will be randomly assigned to one of three groups: a program implemented by advanced undergraduate students in Nutrition and Physical Activity (NUT-PA), a program implemented by Physical Education teachers and Physical Activity students (PEST-PA), or a control group. The intervention will consist of a 6-month obesity prevention program that includes nutrition education, physical activity sessions, and parent participation. The control group will continue with their regular school activities. The primary outcome will be the difference in body fat percentage at 6 months between the NUT-PA group and the control group, as well as between the PEST-PA group and the control group. Secondary outcomes will include BMI Z-score, waist circumference, and various lifestyle parameters. A mixed-effects linear analysis will be conducted using an intention-to-treat approach.

This is a cluster randomized controlled trial with three parallel groups and a 1:1:1 allocation ratio. The current protocol represents the definitive phase of the study, which was previously registered and approved in clinical trials (NCT05461703). The project has been approved by the Research Ethics Committee of the Nursing Department at the Universidad de Sonora (EPD-007-2022).

Schools

Inclusion Criteria:

• School principals, 4th- and 5th- grade teachers willing to participate, availability of space for physical activity classes, and groups with a minimum of 20 students.

Exclusion Criteria:

• Participating in a similar study.

Children

Inclusion Criteria:

• To be a 4th or 5th grade student (9 to 12 years) in one of the participating schools. To be eligible for this study, parents and children will be required to sign an informed consent and assent form, respectively, and had to complete anthropometric measurements (children) and lifestyle questionnaires (parents).

Exclusion Criteria:

• A personal condition that prevents conducting physical activity or a condition that parents consider should exclude their child from participating.

Implementers

Inclusion Criteria:

-Received 80% of the program training. Satisfactory response to a questionnaire that assessed their knowledge of the program following the training.