Washington State Institute for Public Policy

School-based programs to create a healthy food environment
Public Health & Prevention: School-based
Literature review updated November 2015.

These programs improve the food environment in schools through changes such as removing soda and energy dense food from cafeterias and vending machines, improving the nutrition of school meals, promoting water consumption, and encouraging students to bring healthier food from home. Twelve of the 14 programs included in this review also included increased opportunities for physical activity during the school day.

META-ANALYSIS	CITATIONS

**Meta-analysis** is a statistical method to combine the results from separate studies on a program, policy, or topic in order to estimate its effect on an outcome. WSIPP systematically evaluates all credible evaluations we can locate on each topic. The **outcomes** measured are the types of program impacts that were measured in the research literature (for example, crime or educational attainment). **Treatment N** represents the total number of individuals or units in the treatment group across the included studies.

An **effect size** (ES) is a standard metric that summarizes the degree to which a program or policy affects a measured outcome. If the effect size is positive, the outcome increases. If the effect size is negative, the outcome decreases.

**Adjusted effect sizes** are used to calculate the benefits from our benefit cost model. WSIPP may adjust effect sizes based on methodological characteristics of the study. For example, we may adjust effect sizes when a study has a weak research design or when the program developer is involved in the research. The magnitude of these adjustments varies depending on the topic area.

WSIPP may also adjust the second ES measurement. Research shows the magnitude of some effect sizes decrease over time. For those effect sizes, we estimate outcome-based adjustments which we apply between the **first time ES is estimated** and the **second time ES is estimated**. We also report the **unadjusted effect size** to show the effect sizes before any adjustments have been made. More details about these adjustments can be found in our Technical Documentation.
Meta-Analysis of Program Effects
Outcomes measured	Primary or secondary participant	No. of effect sizes	Treatment N	Adjusted effect sizes (ES) and standard errors (SE) used in the benefit-cost analysis						Unadjusted effect size (random effects model)
				First time ES is estimated			Second time ES is estimated
				ES	SE	Age	ES	SE	Age	ES	p-value
Obesity	Primary	14	12400	-0.106	0.039	10	0.000	0.101	12	-0.106	0.007

Citations Used in the Meta-Analysis

Angelopoulos, P.D., Milionis, H.J., Grammatikaki, E., Moschonis, G., & Manios, Y. (2009). Changes in BMI and blood pressure after a school based intervention: The CHILDREN study. European Journal of Public Health, 19(3), 319-325.

Coleman, K.J., Tiller, C.L., Sanchez, J., Heath, E.M., Sy, O., Milliken, G., & Dzewaltowski, D.A. (2005). Prevention of the epidemic increase in child risk of overweight in low-income schools: the El Paso coordinated approach to child health. Archives of Pediatrics & Adolescent Medicine, 159(3), 217-24.

Foster, G.D., Sherman, S., Borradaile, K.E., Grundy, K.M., Vander Veur, S.S., Nachmani, J., . . . Shults, J. (2008). A policy-based school intervention to prevent overweight and obesity. Pediatrics, 121(4), e794-e802.

Haerens, L., Deforche, B., Maes, L., Stevens, V., Cardon, G., & Bourdeaudhuij, I. (2006). Body mass effects of a physical activity and healthy food intervention in middle schools. Obesity, 14(5), 847-854.

Hollar, D., Messiah, S. E., Lopez-Mitnik, G., Hollar, T. L., Almon, M., & Agatston, A. S. (2010). Healthier Options for Public School Children program improves weight and blood pressure in 6- to 13-year-olds. Journal of the American Dietetic Association, 110(2), 261-267.

Luepker, R.V., Perry, C.L., McKinlay, S.M., Nader, P.R., Parcel, G.S., Stone, E.J., . . . Wu, M. (1996). Outcomes of a field trial to improve children's dietary patterns and physical activity: The child and adolescent trial for cardiovascular health (CATCH). Journal of the American Medical Association, 275(10), 768-776.

Marcus, C., Nyberg, G., Nordenfelt, A., Karpmyr, M., Kowalski, J., & Ekelund, U. (2009). A 4-year, cluster-randomized, controlled childhood obesity prevention study: STOPP. International Journal of Obesity, 33(4), 408-417.

Muckelbauer, R., Libuda, L., Clausen, K., Reinehr, T., & Kersting, M. (2009). A simple dietary intervention in the school setting decreased incidence of overweight in children. Obesity Facts, 2(5), 282-285.

Sahota, P., Rudolf, M., Dixey, R., Hill, A., Barth, J., & Cade, J. (2001). Randomised controlled trial of primary school based intervention to reduce risk factors for obesity. British Medical Journal, 323(7320), 1029-1032.

Sallis, J.F., Mckenzie, T.L., Conway, T.L., Elder, J.P., Prochaska, J.J., Brown, M., . . . Alcaraz, J.E. (2003). Environmental interventions for eating and physical activity - A randomized controlled trial in middle schools. American Journal of Preventive Medicine, 24(3), 209-217.

Singh, A.S., Chin A Paw, M.J.M., Brug, J., & van Mechelen, W. (2009). Dutch obesity intervention in teenagers: Effectiveness of a school-based program on body composition and behavior. Archives of Pediatrics and Adolescent Medicine, 163(4), 309-317.

Taylor, R.W., McAuley, K.A., Barbezat, W., Farmer, V.L., Williams, S.M., & Mann, J.I. (2008). Two-year follow-up of an obesity prevention initiative in children: The APPLE project. American Journal of Clinical Nutrition, 88(5), 1371-1377.

Williamson, D.A., Copeland, A.L., Anton, S.D., Champagne, C., Han, H., Lewis, L., . . . Ryan, D. (2007). Wise Mind Project: A school-based environmental approach for preventing weight gain in children. Obesity, 15(4), 906-917.