Frequency Needed for School-based Obesity Intervention

Frequency of Intervention Needed to Improve Weight Outcomes of Mexican-American Adolescents With Overweight or Obesity

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.

The intervention consisted of nutrition lessons based on the traffic light diet, circuit-based physical activity, behavior modification techniques (token economy system, goal setting, self-monitoring), and parental involvement (materials sent home and monthly parent meetings). 80% of time was spent on physical activity and 20% was spent on nutrition. Behavior modification was incorporated into both physical activity and nutrition time. Specifically, instruction and activity time during PE class lasted approximately 40 minutes.

Inclusion Criteria: BMI-for-age (Body Mass Index) percentile ≥ 85 Male or female between ages 10 - 17 years Self-identified as Mexican-American Exclusion Criteria: Student who is pregnant, planning to become pregnant, or becomes pregnant School report of cognitive impairment significantly below average age and/or grade level Use of any weight-loss medication (prescription or nonprescription) for at least 6 months prior to screening Type 1 or 2 diabetes medical diagnosis