Obesity: Supporting Healthier Snack Foods and Beverages Sold or Offered as Rewards in Schools
Findings and Recommendations
The Community Preventive Services Task Force (CPSTF) finds insufficient evidence to determine the effectiveness of interventions supporting healthier snack foods and beverages sold or rewarded in schools. Evidence is considered insufficient based on inconsistent findings for sugar-sweetened beverage consumption outcomes and too few studies for weight and other dietary outcomes.
The CPSTF recommends the following related interventions in school settings:
Healthy Eating Interventions Combined with Physical Activity Interventions
Healthy Eating Interventions Alone
- Meal or Fruit and Vegetable Snack Interventions to Increase Healthier Foods and Beverages Provided by Schools
- Multicomponent Interventions (Meal or Fruit and Vegetable Snack Interventions + Healthier Snack Foods and Beverages) to Increase Availability of Healthier Foods and Beverages in Schools
Physical Activity Interventions
The CPSTF finds insufficient evidence for two other intervention approaches that focus on healthy eating in schools alone and two other intervention approaches that focus on healthy eating combined with physical activity in schools. Read a summary of the findings from all eight reviews of school-based interventions to prevent obesity.
The full CPSTF Finding and Rationale Statement and supporting documents for Obesity Prevention and Control: Interventions to Support Healthier Foods and Beverages in Schools are available in The Community Guide Collection on CDC Stacks.
Intervention
Interventions supporting healthier snack foods and beverages sold or offered as a reward in school aim to provide healthier foods and beverages that will be consumed by students, limit access to less healthy foods and beverages, or both.
- Policies that require foods and beverages sold during the school day, outside of school meal programs, meet established nutritional standards or guidelines
- These are often referred to a “competitive foods and beverages” as they are sold in competition with school meal programs. They may include in-school fundraisers, a la carte foods, vending machines, school stores, and snack bars.
- Celebration rules or policies that encourage healthy foods and beverages be served during classroom celebrations, parties, and special events
- Reward rules or policies that encourage rewards of nonfood items for academic achievement
Interventions may also include one or more of the following:
- Healthy food and beverage marketing strategies: placing healthier foods and beverages where they are easy to select, pricing healthier foods at lower cost, attractive displays, taste tests, or signs promoting healthier options
- Healthy eating learning opportunities, such as nutrition education and other strategies that give children knowledge and skills to choose and consume healthier foods and beverages
About The Systematic Review
In 2013, the Agency for Healthcare Research and Quality (AHRQ) conducted a meta-analysis on the effectiveness of childhood obesity prevention programs. The CPSTF finding is based on a subset of studies from the review that focused on dietary-only approaches in schools (Wang et al., 2013; 15 studies, search period through August 2012) combined with more recent evidence (36 additional studies, search period August 2012 to January 2017).
The 2016 findings about school interventions to prevent obesity update and replace the 2003 CPSTF findings on “School-Based Programs Promoting Nutrition and Physical Activity” and “School-Based Programs to Prevent Obesity.”
Study Characteristics
- Study designs included before/after design with concurrent comparison group (2 studies), prospective cohort (1 study), repeat cross-sectional with comparison (1 study), repeat cross-sectional (3 studies), or post-test only with comparison (6 studies)
- All studies were conducted in the United States
- All studies evaluated interventions conducted in schools alone
- Studies were implemented in elementary schools (1 study), middle schools (4 studies), high schools (5 studies), or a combination of elementary, middle, or high schools (3 studies)
- Studies were set in urban (1 study) or a combination of urban, suburban, or rural (11 studies) settings
- About half of each study population was female (10 studies; 3 studies did not provide information)
Summary of Results
The systematic review included 13 studies with 15 study arms.
Weight-Related Outcomes
- Prevalence of overweight/obesity: one study reported no change (1 study arm) and a significant increase in overweight/obesity prevalence (1 study arm)
- BMI z-score: decreased (1 study with 2 study arms; results were significant in 1 arm)
Diet-Related Outcomes
- Sugar-sweetened beverage intake: mixed outcomes (9 studies)
- Low-nutrient food intake: favorable findings (2 studies)
Summary of Economic Evidence
An economic review of this intervention was not conducted because the CPSTF did not have enough information to determine if the intervention works.
Applicability
Applicability of this intervention across different settings and populations was not assessed because the CPSTF did not have enough information to determine if the intervention works.
Evidence Gaps
- Which intervention activities, competitive foods and beverages, classroom celebrations, parties or special events, nonfood items as rewards, or combinations of these activities are most effective? Which activities are critical to success?
- What are the cumulative effects of adding intervention components? Is a single component equally effective?
- In order to increase comparability what are the “best measures” for dietary intake outcomes?
- Do children act as agents of change by discussing changes in the school environment with parents? Do parents incorporate healthier dietary habits at home?
- How often do schools implement interventions with fidelity? What amount of training is needed for faculty?
- Does effectiveness vary by age group?
- Are national, state, or local policies most effective?
- Approximately half of the studies reported on weight outcomes; future studies should report weight-related outcomes to increase understanding of intervention effectiveness.
- For studies reporting on milk products and alternatives to dairy, what is the fat content of these foods and beverages?
- Do interventions lead to other health benefits such as improvements in cholesterol or blood pressure?
Implementation Considerations and Resources
The CPSTF did not have enough evidence to determine whether the intervention is or is not effective. This does not mean that the intervention does not work, but rather that additional research is needed to determine whether or not the intervention is effective.