Obesity: Meal or Fruit and Vegetable Snack Interventions to Increase Healthier Foods and Beverages Provided by Schools

Related Pages

Findings and Recommendations

The Community Preventive Services Task Force (CPSTF) recommends meal interventions and fruit and vegetable snack interventions to increase the availability of healthier foods and beverages provided by schools. This finding is based on evidence that they increase fruit and vegetable consumption and reduce or maintain the rate of obesity or overweight. Economic evidence shows that meal interventions and fruit and vegetable snack interventions are cost-effective.

The CPSTF recommends the following related interventions in school settings:

Healthy Eating Interventions Combined with Physical Activity Interventions

Healthy Eating Interventions Alone

Physical Activity Interventions

The CPSTF finds insufficient evidence for two other intervention approaches that focus on healthy eating in schools alone and three 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

Meal interventions or fruit and vegetable snack interventions aim to provide healthier foods and beverages that will be consumed by students, limit access to less healthy foods and beverages, or both.

Interventions must include one of the following components:

  • School meal policies that ensure school breakfasts or lunches meet specific nutrition requirements (e.g., School Breakfast Program, National School Lunch Program)
  • Fresh fruit and vegetable programs that provide fresh fruits and vegetables to students during lunch or snack

Each intervention may also include one or more of the following:

  • Healthy food and beverage marketing strategies
    • Placing healthier foods and beverages where they are easy for students to select
    • Pricing healthier foods and beverages at a lower cost
    • Setting up attractive displays of fruits and vegetables
    • Offering taste tests of new menu items
    • Posting signs or verbal prompts to promote healthier foods and beverages and new menu items
  • Healthy eating learning opportunities such as nutrition education and other strategies that give children knowledge and skills to help choose and consume healthier foods and beverages.

Healthier foods and beverages include fruits, vegetables, whole grains, low-fat or fat-free dairy, lean meats, beans, eggs, nuts, and items that are low in saturated fats, salt, and added sugars, and have no trans fats. Less-healthy foods and beverages include those with more added sugars, fats, and sodium.

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 implemented in 6 intervention settings. 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).

This review was conducted on behalf of the CPSTF by a team of specialists in systematic review methods, and in research, practice and policy related to obesity prevention and control. 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 group randomized controlled trials (7 studies), group non-randomized (2 studies), repeat cross-sectional with comparison (1 study), time series (1 study), single group before-after (4 studies), repeat cross-sectional (3 studies), or post-test only with comparison (7 studies).
  • Studies were conducted in the United States (12 studies), Canada (3 studies), Norway (3 studies), the United Kingdom (1 study), the Netherlands (1 study), Spain (1 study), Australia (1 study), Denmark (1 study), Greece (1 study), and one study collected data from 3 countries (Norway, the Netherlands, and Spain).
  • Studies were conducted in schools alone (23 studies) or in schools plus one or more additional settings (2 studies).
  • Studies were conducted in elementary schools (11studies), middle schools (6 studies), high school (2 studies), or a combination of elementary, middle, or high schools (6 studies).
  • Studies were set in urban (3 studies), rural (2 studies), or a combination of urban, suburban or rural (9 studies) settings.
  • About half of each study population was female (22 studies; 3 studies did not provide information).
  • Twelve studies reported race/ethnicity with study populations identifying as white (median: 58.9%; 9 studies), black (median: 15.4%; 8 studies), Hispanic (median: 18.5%; 8 studies), First Nation (100.0%; 2 studies), and other (100%; 1 study).

Summary of Results

The systematic review included 25 studies with 26 study arms.

Weight-Related Outcomes

  • Overweight/obesity prevalence median decrease of 9.6 percentage points (5 studies)
  • BMI z-score median increase of 0.01 (not significant; 3 studies)

Diet-Related Outcomes

  • Fruit or vegetable intake 20.0% increase (9 study arms)

Summary of Economic Evidence

A systematic review of economic evidence indicates that meal interventions and fruit and vegetable snack interventions are cost-effective. All monetary values are reported in 2016 U.S. dollars.

The economic review included 7 studies (4 from the United States, 1 from Norway, 1 from the Netherlands, and 1 from Taiwan).

  • Median intervention cost per student per year for fruit and vegetable snack interventions: $50 (3 studies)
  • Incremental intervention cost per student per year to provide school meals that meet nutrition guidelines: $198 and $624 (2 studies)
  • Lifetime savings per student in healthcare costs due to two fruit and vegetable snack interventions: $28 and $17 (1 study)
  • Annual savings per student in healthcare cost due to improved nutritional content of school meals: $17 (1 study)
  • Cost per quality adjusted life year (QALY) gained was $10,800 (1 study). This estimate is less than $50,000 a benchmark for cost-effectiveness.
  • Costs per disability adjusted life year (DALY) averted were $8,014 and $14,934 (2 studies). Both estimates are considered cost-effective based on a per capita annual income of $49,390 in the Netherlands.

Applicability

Based on results for interventions in different settings and populations, findings should be applicable to the following:

  • Elementary and middle school-aged children
  • Girls and boys
  • Students from different racial and ethnic backgrounds
  • Students from different income levels
  • Urban, suburban, and rural environments

Evidence Gaps

  • Which intervention activities, school breakfast or lunch, fresh fruit and vegetable programs, or combinations of 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 students’ age group?
  • Are national, state, or local policies most effective?
  • 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?
  • What does the intervention cost to implement and what are the major drivers of cost?
  • What are long term benefits of averted healthcare cost and improved productivity in adulthood associated with interventions shown to improve nutrition and prevent obesity in childhood?

Implementation Considerations and Resources

  • Different possible combinations of components, the levels at which changes are made (i.e., federal, state or provincial, district, or school), and the school capacity for implementing the intervention(s) may impact intervention effectiveness.
  • Some intervention components (e.g., implementing National School Lunch Program guidelines) may be required if a school is participating in the National School Lunch program.
  • Intervention success may vary based on school characteristics and intervention components. Schools with greater resources will likely be better able to implement interventions with high fidelity compared with schools that have higher needs.
  • Some school communities may be resistant to change due to time or monetary constraints.
  • Interventions that include an educational component must compete with other educational demands in the school.

Crosswalks