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Emoticon use Increases Plain Milk and Vegetable Purchase in a School Cafeteria without Adversely Affecting Total Milk Purchase

      Abstract

      Purpose

      Choosing poor-quality foods in school cafeterias is a risk factor for childhood obesity. Given the option, children often select chocolate milk over plain white milk. Efforts to increase plain white milk selection, such as banning chocolate milk in school cafeterias, increases plain white fat-free milk (PWFFM) purchase but decreases the overall milk purchase. The purpose of this study was to determine whether emoticon placement next to healthful foods would increase healthful purchases, particularly PWFFM.

      Methods

      In an inner city elementary school with 297 children, “Green Smiley Face” emoticons were placed to encourage the purchase of healthful foods including an entrée with whole grains, fruits, vegetables, and PWFFM. Purchase data were obtained from cash register receipts. Differences were analyzed by χ2 Care and Statistical Process Control (SPC) and Graphical Methods.

      Results

      Only 7.4% of students selected white milk at baseline compared with 17.9% after the emoticons were placed (P < 0.0001). There was a decrease in chocolate milk purchase from 86.5% to 77.1% with the addition of the emoticons (P < 0.001). There was no significant difference in total milk purchase: 93.4% before the emoticons compared with 94.9% after. There was no significant change in the purchase of entrée or fruits. However, there was, a significant increase in vegetable purchase from 0.70 vegetables purchased per student per day to 0.90 by SPC (>8 points above the mean).

      Implications

      The addition of emoticons increases the purchase of PWFFM and vegetables in a school cafeteria setting without adversely affecting total milk sales. Emoticons offer a practical, low-cost means to improve food selection by children.

      Key words

      Introduction

      Childhood obesity is a major pediatric health issue with more than one third of American children overweight or obese.
      • Ogden C.L.
      • Carrol M.D.
      • Kit B.D.
      • Flegal K.M.
      Prevalence of Obesity and Trends in Body Mass Index Among US Children and Adolescents, 1999-2010.
      Risk factors for childhood obesity include inadequate fruit, vegetable, and milk consumption and excess consumption of sugary drinks. This has led the American Academy of Pediatrics to recommend lifestyle changes to correct these factors.
      • Spear B.A.
      • Barlow S.E.
      • et al.
      Recommendations for Treatment of Child and Adolescent Overweight and Obesity.
      Poor choices in the school cafeteria are a risk factor for obesity as well.
      • Finkelstein D.M.
      • Hill E.L.
      • Whitaker R.C.
      School food environments and policies in US public schools.
      Although there is variability in quality of what children choose with the school lunch program, such as selecting flavored milk over plain low-fat milk, packed lunches from home are often significantly poorer in nutritional quality overall. Therefore, efforts to increase school lunch program participation and selection of more healthful components would improve the quality of students’ diets.
      • Farris A.R.
      • Misyak S.
      • Duffey K.J.
      • et al.
      Nutritional comparison of packed and school lunches in pre-kindergarten and kindergarten children following the implementation of the 2012–2013 national school lunch program standards.
      Additionally, the school setting is an attractive place to intervene with obesity prevention programs because a larger number of children can be reached in a relatively uniform and consistent manner.
      • Katz D.L.
      • O’Connell M.
      • Njike1 V.Y.
      • et al.
      Strategies for the prevention and control of obesity in the school setting: systematic review and meta-analysis.
      Given the option, children often select chocolate milk over plain milk in school cafeterias. Efforts to increase plain white milk selection, such as banning chocolate milk in school cafeterias, increases plain white fat-free milk (PWFFM) purchase , but decreases overall milk purchase.
      • Hanks A.S.
      • Just D.R.
      • Wansink B.
      Chocolate milk consequences: a pilot study evaluating the consequences of banning chocolate milk in school cafeterias.
      In experimental settings, emoticons have been used to help school-age children make better food choices.
      • Privitera G.J.
      • Phillips T.E.
      • Misenheimer M.
      • Paque R.
      “The effectiveness of “emolabeling” to promote healthy food choices in children preschool through 5th grade”.
      The purpose of this study was to determine whether emoticon placement next to healthful foods would increase healthful purchase, particularly PWFFM.

      Methods

      In October 2013, an Emoticon intervention was implemented at the Frederick Douglass Elementary School (FD) of Cincinnati Public Schools. FD is an inner city elementary school of 297 children, grades kindergarten through 6, with a demographic breakdown of 92.7% African American, 49.2% male, 50.85% female, and 98.1% free lunch–eligible children.

      Startclass. Frederick Douglass School, Cincinnati, Ohio. http://public-schools.startclass.com/l/69107/Frederick-Douglass-Elementary-School. Accessed 7 March 2015.

      The school participates in the U.S. Department of Agriculture National School Lunch Program for free or reduced-cost lunches, where students may select an entrée with whole grains, low-fat plain or chocolate milk, and up to 2 fruit or vegetable servings. Competitive foods such as whole-grain cupcakes and cookies are sold as well. Children self-serve and are required to take 3 meal components and may select as many as 5.
      Signs with “Green Smiley Face” emoticons (Figure 1) were placed next to PWFFM, fruits, vegetables (including a salad bar), and the main entrée to encourage the purchase of healthful foods. A cafeteria staff worker explained the intervention to students on the first day of the intervention and intermittently throughout the study period. Purchase data were obtained from cash register receipts supplied by the Food Services Department of Cincinnati Public Schools. Differences were analyzed by a χ2 test using SAS version 9.3 (SAS Institute, Cary, North Carolina) when children were limited to the purchase of 1 item (entrée, PWFFM, chocolate milk). For fruits and vegetables, students could purchase more than 1 item in that category and Statistical Process Control (SPC) and Graphical Methods were used. Run charts were constructed for food items, and 8 consecutive data points above an established mean were considered statistically significant. This project was reviewed by the Cincinnati Children’s Hospital Medical Center Review Board and determined not to be a Human Subjects Research project and thus exempt.

      Results

      Cafeteria sales receipts were obtained for the 4-month study period from October 1, 2013 through January 31, 2014. From October 1, 2013 through December 3, 2013, no signs were placed to collect baseline data. The emoticon signs were placed from December 4, 2013 through January 31, 2014 adjacent to the preferred healthful foods of PWFFM, vegetables including the salad bar, fruits, and entrées with whole grains. Figure 2 shows PWFFM sales versus time. Only 7.4% of students selected white milk at baseline compared with 17.9% after the emoticons were placed (P < 0.0001). This represents a 141% increase in PWFFM purchase. Figure 3 shows low-fat chocolate milk sales with time. There was a decrease in chocolate milk purchase from 86.5% at baseline to 77.1% with the addition of the emoticons (P < 0.001), an 11% decrease. There was no significant difference in total milk purchase, with 93.4% selecting either plain or chocolate milk before the emoticons compared with 94.8% after the emoticons were placed. There was also no significant change in fruit purchase (Figure 4). However, there was a significant increase in vegetable purchase from 0.70 vegetables purchased per student per day to 0.90 (Figure 5) by SPC methods (>8 data points above the mean). Ninety-six percent of students purchased an entrée per day during the intervention period with no significant variation before and after emoticon placement by SPC methods.
      Figure thumbnail gr2
      Figure 2Plain white fat-free milk purchase with time. Annotation is when emoticon signs were placed. n is the number of children making school lunch purchases on that day. The control limits represent points that fall within 3 SDs of the mean.
      Figure thumbnail gr3
      Figure 3Chocolate milk purchase with time. Annotation is when emoticon signs were placed. n is the number of children making school lunch purchases on that day. The control limits represent points that fall within 3 SDs of the mean.
      Figure thumbnail gr4
      Figure 4Fruit purchase with time. Annotation is when emoticon signs were placed. The control limits represent points that fall within 3 SDs of the mean.
      Figure thumbnail gr5
      Figure 5Vegetable purchase with time. Annotation is when emoticon signs were placed. The control limits represent points that fall within 3 SDs of the mean.

      Discussion

      With our intervention of using signs with emoticons to encourage healthful food purchase, we were able to increase the purchase of PWFFM and lower the purchase of chocolate milk. This low-cost and simple strategy compares favorably in impact with other school cafeteria interventions.

      List JA, Samek AS. The behavioralist as nutritionist: leveraging behavioral economics to improve child food choice and consumption. Journal of health economics. 2015;39:135–146.

      School-based cafeteria interventions are an attractive option for improving nutrition because a large number of children can be reached. Low-income children who are at greatest risk of poor nutrition and obesity are also most likely to benefit by better food selection efforts because their participation in the National School Lunch Program for free and reduced-cost lunch is high.
      • Wang Y.
      “Cross-national comparison of childhood obesity: the epidemic and the relationship between obesity and socioeconomic status”.
      Historically, approximately two thirds of children choose flavored milk, most often chocolate, over plain milk when given the option in school cafeteria settings.

      Prime Consulting Group (2012) ‘‘2011–2012 Annual School Channel Survey.Project administered by Milk Processor Education Program, National Dairy Council, and the School Nutrition Association. http://www.nationaldairycouncil.org/sitecollectiondocuments/education_materials/flavored_milk/dcd11-4w.pdf. Accessed 8 April 2015.

      Although milk is thought to have beneficial effects because of its high vitamin D and calcium content, flavored milk has considerably more sugar than plain milk.
      • Drewnowski A.
      “The contribution of milk and milk products to micronutrient density and affordability of the US diet”.
      By offering equal access to flavored milk and plain milk, children may interpret an equal endorsement of both foods by a teaching institution and view flavored milk as a healthful food. Thus, it is important for schools to consider how they are presenting foods to children who are impressionable and developing eating habits that may be carried into adulthood.
      • Puhl R.M.
      • Schwartz M.B.
      “If you are good you can have a cookie: How memories of childhood food rules link to adult eating behaviors”.
      Eliminating chocolate milk was explored in the Oregon school district where only plain skim milk was offered to children in grades kindergarten to 5. Although plain milk purchase increased 152%, overall milk purchase decreased by 9.9%. In our intervention, we were able to successfully encourage the more healthful selection of plain milk without decreasing overall milk purchase. Although we did maintain children’s ability to choose, our overall impact on reducing chocolate milk selection was more modest than the Oregon banning intervention. Our intervention, however, was low cost and easy to implement.
      There are several limitations to our study. We did not have a control group and relied only on a before-and-after picture using SPC Graphical methods for evaluation. Our study was only 3 months of active intervention, and it is not known whether the effect of the emoticons will diminish with time. Finally, we do not have consumption data and cannot address whether the students who chose the preferred plain milk actually drank it. Still, we show that signs with “Green Smiley Face” emoticons can be an effective and low-cost intervention in improving healthful food selection by elementary school students. The emoticon intervention presents a reasonable alternative in schools that hope to increase plain milk purchase without eliminating student food choice.

      Conflicts of Interest

      The authors have no conflicts of interest to disclose. The study was not supported by a grant.

      Acknowledgments

      We gratefully acknowledge of the Frederick Douglass cafeteria staff, the children of the Frederick Douglass Elementary School, and the Cincinnati Children’s Hospital Medical Center Population Health Team for their efforts with this project.

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