This randomized controlled trial compared changes in Mexican-American, adolescent standardized body mass index (zBMI) from a school-based obesity intervention given zero, one, three, or five days a week.

Efficacious school-based interventions have been intensive making it difficult for interventions to be scaled. The more components there are to an intervention, typically the better the results. Instead of decreasing intensity via the removal of intervention components, this randomized controlled trial aimed to compare changes in Mexican-American adolescent standardized body mass index (zBMI) based on the number of days per week they received a multi-component intervention. Mexican-American middle school students (n=203) with overweight or obesity were recruited from an independent school district in Houston. Students were randomized to receive an obesity intervention with established efficacy zero (control), one, three, or five days/week. In each condition, 80% of intervention time was allocated to physical activity and 20% to nutrition. Directly measured height and weight were used to calculate zBMI.

Inclusion Criteria:

1. BMI-for-age (Body Mass Index) percentile ≥ 85
2. Male or female between ages 10 - 17 years
3. Self-identified as Mexican-American

Exclusion Criteria:

1. Student who is pregnant, planning to become pregnant, or becomes pregnant
2. School report of cognitive impairment significantly below average age and/or grade level
3. Use of any weight-loss medication (prescription or nonprescription) for at least 6 months prior to screening
4. Type 1 or 2 diabetes medical diagnosis

There is no plan to make IPD available to other researchers