STUDY: Assessing the Effectiveness of OSNAP Scaled-Up Nationally

A new study from the Harvard T. H. Chan School of Public Health looked at the effects and costs of two training models to scale-up the Out-of-School Nutrition and Physical Activity (OSNAP) Initiative at a national level, and noted some promising findings.

In this group-randomized trial, authors studied implementation of the Out-of-School Nutrition and Physical Activity (OSNAP) initiative, an intervention that already has strong evidence that it can effectively increase vigorous physical activity and improve the diets of young children.

Nutrition and physical activity standards have been established for out-of-school time, but no best practices exist for professional development needed for implementation and developing the skills of this largely part-time, low-wage workforce. This study tested different forms of trainings for out-of-school time staff. Specifically, the authors tested a train-the-trainer approach as well as an online approach to OSNAP among YMCA sites.

The authors designed a group-randomized trial with three groups. A total of 70 YMCA sites that represented the southern, midwestern, and northeastern United States were recruited to participate. The sites were randomly assigned in thirds to either receive an in-person train-the-trainer training session, an online training with self-paced learning modules, and a control group that did not receive any OSNAP training. Fifty-three afterschool sites from three YMCAs across various regions of the country completed baseline and follow-up observations. The authors also collected cost data to determine what resources would be needed to implement each training model.

Key findings from the trial included:

  • On average, YMCA sites that received in-person trainings achieved more of the OSNAP goals when compared to those in the control group
    • Those that received online trainings did not see significantly greater increases in goals when compared to the control group
  • The in-person training model cost $678 per person, while the online training model cost $336 per person

In conclusion, this trial shares some promising findings for scaling-up the OSNAP initiative on a national level. While the in-person approach appears to be the most effective based on these findings, an online training model might be important to consider from a feasibility and cost-saving perspective, especially in those places where in-person training might be challenging. The study highlights the importance of identifying strategies for translating evidence-based interventions in the field of public health prevention into practice.

Suggested Citation:
Lee RM, Barrett JL, Daly JG, Mozaffarian RS, Giles CM, Cradock AL, Gortmaker SL. Assessing the effectiveness of training models for national scale-up of an evidence-based nutrition and physical activity intervention: a group randomized trial. BMC Public Health. 2019;19(1587). doi:

Address correspondence to Rebekka Lee, ScD,