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The Out of School Nutrition and Physical Activity (OSNAP) Initiative is a PSE change intervention designed to increase healthy nutrition and physical activity and reduce screen time for children, including the frequency with which water is served during snack at afterschool programs. By promoting water, the OSNAP Initiative decreases the caloric impact of beverages served in afterschool programs. OSNAP, through its interactive website,, provides afterschool program staff and organizational leaders with resources to improve their program practices and policies related to healthy foods, drinks, and physical activity.  One component of the OSNAP initiative focuses on providing access to free drinking water at snack time for children in afterschool programs.

Intervention Target Behavior: Healthy Eating, Physical Activity and Reducing Screen Time 

SNAP-Ed Strategies:  PSE Change

Intervention Reach and Adoption

OSNAP targets elementary school-aged children in schools and community programs operating afterschool programs. The OSNAP study was conducted in afterschool programs in urban Boston. The population served by the afterschool programs was racially, linguistically, and economically diverse. Schools at which the programs were located had student populations that were 37.7% black, 10.6% white, and 37.9% Hispanic. On average, 81.2% of children qualified for free/reduced-price lunch. The mean enrollment across afterschool programs was 72.0 children and the mean child age was 7.8 years.

Settings: Pre-K & Childcare, Community-wide, Schools 

Age/Population Group: Elementary School

Race: All

Ethnicity: All

Intervention Components

OSNAP includes the following main components:

  1. Complete assessment of current afterschool program practices. Programs assessed their policies and practices related to healthy eating, beverages, and physical activity. This included collecting data on beverages currently being served to children at afterschool snack.
  2. Hold learning communities, including training of afterschool program coordinators and writing afterschool wellness policies. Afterschool program directors and staff were invited to participate in a series of three learning community sessions. The meetings were hosted at participating sites and held at various times of the day to ensure participation. As part of the sessions, staff set actionable goals to improve program practices, wrote relevant policies, and communicated changes to parents, students, the school nutrition service, and school administrators.
  3. Review and revise district snack menus and beverage serving plans.  The OSNAP team partnered with the Boston Public Schools Food and Nutrition Service to review snack menus and provide nutritional and price analyses to support modifications to menus and beverage serving plans. Modified menus promoted water as the primary beverage.
  4. Establish water-delivery systems to ensure children are served water during snack time. Water-serving plans were determined based on infrastructure issues, program size, and applicable costs. Each plan had to be tailored to the needs of the school or organization operating the afterschool program. Options for providing water ranged from tap water in pitchers or jugs to bottled water in coolers.
  5. Engage stakeholders through parent newsletters, and get buy-in from food and nutrition services and school administrators. Understanding and acceptance of the program by parents and school staff were essential to its success. To achieve the goal of providing water at snack every day, the learning communities decided on action steps that included:  creating policies in family handbooks, announcing new practices at staff meetings and assemblies, and communicating with families via newsletters and during program events. OSNAP provides sample language and templates for parent communications (
  6. Implement hydration units from Food & Fun Afterschool Curriculum in afterschool programs. Afterschool staff received the Food & Fun curriculum during learning communities and had the option to receive training on implementation of the curriculum. Part of the curriculum includes involving children in art activities and weekly water-helper duties.
Intervention Materials

A variety of intervention and training materials are provided on the OSNAP website. The OSNAP training resources have been evaluated and proven to be effective. OSNAP provides not only materials that you can use immediately with children and families, but also training templates and action planning guides to get afterschool program staff on board, organized, and excited to promote healthy practices and policies.

The intervention has been developed into a CEU-eligible on-demand module via Better Kid Care.  

Evidence Summary

The OSNAP intervention was tested in a randomized controlled trial. Twenty afterschool programs in Boston were randomly assigned to the intervention group or a delayed intervention control group (10 sites in each group).  Sponsoring agencies responsible for the afterschool programs included the Boston Public Schools, YMCA, Boys & Girls Club, and Boston Center for Youth and Families. Prior to randomization, sites were matched on the type of agency overseeing the afterschool program, snack provider, physical activity facilities, and school-level race/ethnicity, and socio-demographic composition. Sites assigned to the control group were given the opportunity to participate in the intervention the following school year.

Primary and secondary outcomes of the OSNAP intervention related to drinking water access included average changes in: 1) ounces of water served at snack per day (primary); 2) beverage calories served at snack per day (secondary); 3) ounces of juice and milk served at snack per day (secondary); and 4), number of times each beverage was served at snack per day (secondary).  Trained observers (blinded to the study group assignment) observed snack serving on 5 consecutive days at both baseline and follow-up. All sites completed the study.

Intervention Effects:

Of the planned observation days (100 total), 97 were completed (3 sites were observed for 4 days instead of 5 because of holiday schedules). After 6 months, the comparison of afterschool programs in the study intervention vs. control sites showed:

  • increased volume of water served by a mean of 3.6 oz. per day per child;
  • decreased calories from beverages served by a mean of 60.9 kcal per day; and
  • increased frequency of water being served to children by a mean of 0.6 times (or 3 additional times over a 5-day school week)

All of these outcomes were statistically significant.  Milk servings decreased by a mean of 0.3 servings per day, but this change achieved only borderline statistical significance.  Servings of juice were not significantly reduced with a mean change of 0.2 servings per day.

In a 3-arm group-randomized trial conducted to compare effectiveness of in-person and online training models for scaling up the intervention compared to controls, on average, sites in the in-person arm achieved 0.44 additional OSNAP goals compared to controls (95%CI 0.02, 0.86, p = 0.04). Increases in the number of additional goals achieved in sites in the online arm were not significantly greater than control sites (+ 0.28, 95% CI -0.18, 0.73, p = 0.24). Goal-specific improvements were observed for increasing water offered in the in-person arm and fruits and vegetables offered in the online arm.  

This pilot trial presents promising findings on implementation strategies for scale-up. It validated the in-person training model as an effective approach. The less expensive online training may be a useful option for geographically disbursed sites where in-person training is challenging.  

Evidence Base: Research-tested

Evaluation Indicators

Based on the SNAP-Ed Evaluation Framework, the following outcome indicators can be used to evaluate intervention progress and success.

 Readiness and Capacity - Short Term (ST)Changes - Medium Term (MT)Effectiveness and Maintenance - Long Term (LT)Population Results (R)
IndividualST1, ST3MT1, MT3LT1LT3 
Environmental SettingsST5MT5, MT6LT5, LT6
Sectors of Influence MT9 
Evaluation Materials

The team that created and evaluated OSNAP at the Harvard Prevention Research Center on Nutrition and Physical Activity created several materials for its evaluation that are available for your use. Some of these tools have been incorporated into the evaluation plan that Center TRT developed. Please provide credit to the Out of School Nutrition and Physical Activity (OSNAP) Initiative or to Food & Fun Afterschool (as relevant) by the Harvard Prevention Research Center on Nutrition and Physical Activity when reproducing materials in the original form:

  • Action Planning Tool Document- Designed to help practitioners set goals and identify action steps for creating healthier nutrition, physical activity and screen time practices at an afterschool program. Available as a PDF.
  • Policy Assessment Tool- Tool for assessing an afterschool program's policies. Available as a PDF.
  • Daily Practice Assessment Tool- Observation tool for assessing afterschool practices: Available as a  PDF.
  • Food & Fun Afterschool Planning Tool- A tool designed to help plan the use of the Food & Fun afterschool curriculum. Staff can make note of which activities children enjoy the most and how they communicate each unit's healthy goal to families. On website here.
  • Food & Fun Afterschool Family Engagement Planning Tool- A tool designed to record and plan the strategies that programs will use to promote nutrition and physical activity with families. On website here.

Center TRT developed an evaluation logic model and evaluation plan for the Out of School Nutrition and Physical Activity (OSNAP) Strategies to Increase Drinking Water Access, an intervention to increase access to drinking water for children in afterschool programs. The logic model is intended to guide the evaluation process (as opposed to the planning process); the evaluation plan focuses on the implementation and effectiveness of an approach like the OSNAP program in increasing access to drinking water. The evaluation plan addresses the reach, adoption, extent of implementation and effectiveness of the OSNAP program in changing policies and practices related to drinking water in afterschool programs.  The evaluation is a pre-post design with no comparison group. This evaluation plan provides guidance on evaluation questions and types and sources of data for both process and outcome evaluation. If you are interested in answering evaluation questions not listed in the evaluation plan, please refer to the list of additional evaluation questions here.

  • Logic Model
  • Evaluation Plan


Additional Information

Website: The OSNAP website ( includes OSNAP's goals for creating healthier out-of-school environments for children, the ability to create an account to assess your program and create a customized action plan, access to training curricula and other resources to help make healthy changes in your program, and additional resources to learn more about the OSNAP initiative.

Contact Person:

Rebekka Lee

Lecturer, Harvard T.H. Chan School of Public Health



*Updated as of August 4, 2023

Resource Type
Age/Population Group
SNAP-Ed Strategies
Evidence Base