Skip to main content Accessibility help
×
Home
Hostname: page-component-684899dbb8-xt4p2 Total loading time: 0.368 Render date: 2022-05-28T00:56:57.726Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true }

Reformulation of pizza crust in restaurants may increase whole-grain intake among children

Published online by Cambridge University Press:  26 August 2014

Aimee Tritt
Affiliation:
Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, St. Paul, MN 55108, USA
Marla Reicks*
Affiliation:
Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, St. Paul, MN 55108, USA
Len Marquart
Affiliation:
Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, St. Paul, MN 55108, USA
*
*Corresponding author: Email mreicks@umn.edu
Rights & Permissions[Opens in a new window]

Abstract

Objective

Whole-grain intake among children is well below recommendations. The purpose of the present study was to test the acceptability and liking of pizza made with whole-grain crust compared with refined-grain crust among children in restaurant and school settings.

Design

Plate waste data were collected via observation from child restaurant patrons consuming pizza made with either whole-grain or refined-grain crust. Waste was estimated by trained observers over eight months (August 2012–March 2013). Percentage waste was calculated and compared by crust type. A taste test was conducted with school children who tasted pizza made with whole-grain crust alongside pizza made with refined-grain crust and rated their liking of each product. Liking ratings were compared by crust type.

Setting

Five Green Mill restaurant (a Midwest US chain) locations and one elementary school in the Minneapolis/St. Paul metropolitan area, Minnesota, USA.

Subjects

Child restaurant patrons (n 394) and school children (n 120, grades 3–5).

Results

Children consumed as much of the pizza made with whole-grain crust (42·1 %) as the pizza made with refined-grain crust (44·6 %; P=0·55), based on an average serving size of 350–400 g. Liking ratings for both types of pizza were high (>4·5 of 5) and did not differ by crust type (P=0·47).

Conclusions

These positive consumption and liking outcomes indicate that whole-grain pizza crust is well accepted among children in a restaurant setting. The impact on whole-grain intake could be substantial if large, national restaurant chains served pizza made with whole-grain crust.

Type
Short Communication
Copyright
Copyright © The Authors 2014 

Studies included in a recent review have shown that a diet rich in whole grains can reduce risk of heart disease, diabetes and weight gain( Reference Ye, Chacko and Chou 1 ). The 2010 Dietary Guidelines for Americans call for a reduction in the number of servings of refined grains and consumption of at least half of total grains as whole grains( 2 ). However, 2009–2010 National Health and Nutrition Examination Survey (NHANES) data show that only 2·9 % of children/adolescents (2–18 years) consume the recommended three daily whole grain ounce-equivalents, while 38·8 % consume no whole grains( Reference Reicks, Jonnalagadda and Albertson 3 ).

Pizza is a popular food commonly consumed by children and adolescents. On any given day, 22 % of US children aged 6–11 years and adolescents aged 12–19 years consume pizza according to NHANES data (2007–2010)( Reference Rhodes, Adler and Clemens 4 ). Pizza is offered in 36 % and 40 % of middle- and high-school menus, respectively, based on a specified target week among schools participating in the US National School Lunch Program( Reference Condon, Crepinsek and Fox 5 ). However, NHANES 2009–2010 data show that the food category of grain mixtures, which includes pizza crust, accounts for only 3 % of the total whole-grain intake among children and adolescents( Reference Reicks, Jonnalagadda and Albertson 3 ). Flour made from white whole wheat can replace refined or red whole-wheat flour in many applications. White whole wheat has the pale hue and mild flavour of refined grain because it lacks a gene for bran colour( 6 ). An earlier study among US elementary-school children showed that consumption of pizza with crust containing white whole-grain flour was the same as pizza with crust containing refined-grain flour( Reference Chan, Vickers and Marquart 7 ).

A large proportion of daily energy intake (33 %) is consumed away from home according to US NHANES 2005–2008 data, and foods consumed away from home are less likely to be whole grain compared with foods consumed at home (0·43 v. 0·09 ounces per 4186·8 kJ)( Reference Lin and Morrison 8 ). Although substituting whole-grain for refined-grain flour is a successful approach for several grain products in schools, including pizza( Reference Chan, Vickers and Marquart 7 , Reference Chu, Warren and Sceets 9 , Reference Toma, Omary and Marquart 10 ), to date no studies have determined if similar results can be achieved in a restaurant setting. Therefore, the purpose of the present study was to test whether plate waste and liking differed for pizza made with whole-grain compared with refined-grain crust among children in restaurant and school settings.

Experimental methods

Pizza crust formulations were developed by Executive Chefs at Green Mill (a Midwest US restaurant chain) and ConAgra Foods, Inc. The flour in the whole-grain crust was a blend of hard white winter, whole-wheat flour (55 %; Ultragrain; ConAgra Mills, Omaha, NE, USA) and hard red winter, refined-wheat flour (45 %). The flour in the refined-grain crust was hard red winter, refined wheat flour only (100 %). The pizza was the same serving size as an individual adult pizza served in this chain (approximately 10 inches in diameter and 350–400 g). The whole-grain and refined-grain crusts contained 6·7 g and 2·5 g of dietary fibre per serving, respectively, based on a nutritional analysis of similar products( 11 ). The same crust formulations were used in the restaurant and school settings.

Participants

Participants in the school setting included 3rd–5th graders from one elementary school in the Minneapolis, Minnesota metropolitan area who rated liking for the pizza products in April 2013. This age group (8–11 years) was asked to participate because older children have been more effective at differentiating between product samples( Reference Kroll 12 ). The school had 405 students in kindergarten–6th grade, of whom 45 % were white, 25 % were Asian and 30 % were African American, Hispanic and American Indian. Pizza plate waste data were collected in the restaurant setting from participants consuming pizza at one of five Green Mill restaurant locations in the Minneapolis/St. Paul metropolitan area between August 2012 and March 2013. The study was conducted according to the guidelines laid down in the Declaration of Helsinki and all procedures involving human subjects were approved by the University of Minnesota Institutional Review Board. In the school setting, parents provided written consent and children provided written assent. Consent and assent were not obtained in the restaurant setting, as this part of the study was exempted by the same Institutional Review Board as observations of public behaviour.

School procedures

Children (n 131) were asked to rate their liking of two samples of cheese pizza, one with whole-grain crust and one with refined-grain crust. Children rated their liking of each on a 5-point hedonic scale with descriptors ranging from 1=‘dislike a lot’ to 5=‘like a lot’( Reference Popper and Kroll 13 ). Samples and rating forms were randomized so that some children tasted the whole-grain crust first while others tasted the refined-grain crust first. Eleven forms were eliminated due to incomplete or illegible data, leaving 120 complete responses.

Restaurant procedures

Child restaurant patrons consuming pizza made with whole-grain or refined-grain crust were observed by one of six trained observers. Observers attempted to observe all children who appeared to be 3–13 years of age several evenings per week over an 8-month period in five restaurant locations. Children were accompanied by parents and/or other adults and were unaware they were being observed. No identifying data were collected, although observers recorded the child’s gender and approximate age.

Observers recorded the date, time, restaurant location, pizza crust type, number of children and adults at the table, number and type(s) of children’s pizza(s) ordered, other foods eaten by the child, whether the pizza was shared, the percentage of meal time the child was observed and the overall percentage of pizza crust not eaten by the child (percentage waste). An observation form was developed and tested in simulated and actual restaurant settings to record percentage waste (Fig. 1). To estimate percentage waste, observers shaded the portion of uneaten pizza remaining on children’s plates on a pizza-shaped diagram (Fig. 1). Intra- and inter-observer reliability was assessed in a simulated environment. Agreement was defined as the estimated percentage waste per pizza falling within 10 % for all observers. The number of pizzas with percentage waste agreement was divided by the total number of pizzas observed at each session. Mean inter-observer reliability for three sessions was 0·86. Intra-observer reliability was calculated similarly, with each person observing the same pizza twice within each session. Mean intra-observer reliability was 1·0. Observed estimates were highly correlated (r=0·88) with weighed plate waste.

Fig. 1 The observation form developed to record percentage waste in restaurant settings

Statistical analyses

Data were analysed using the SAS statistical software package version 9·3, with comparisons made at α=0·05. For the taste test, liking ratings were compared across the two types of pizza crust using paired t tests and within grade, age and gender groups using ANOVA or t tests. For observation of pizza consumption, t tests were used for continuous variables and χ 2 tests for categorical variables. PROC GLM was used to assess differences in percentage waste (dependent variable) by crust type (independent variable). Because significant differences were observed in the number of children who consumed whole-grain and refined-grain pizza crust by gender, pizza toppings and ‘shared consumption’ (yes or no), these variables were also included in the model.

Results

In the school setting, 27·5 %, 34·2 % and 38·3 % were in the 3rd, 4th and 5th grades, respectively. Slightly less than half were girls (49·2 %). The mean liking ratings for pizza made with whole-grain and refined-grain crust were 4·5 (sd 0·9) and 4·6 (sd 0·8), respectively, and were not significantly different (P=0·47). No significant differences were observed in liking ratings when children were grouped by age, grade or gender.

In the restaurant setting (Table 1), 194 and 200 children were observed eating pizza with refined-grain and whole-grain crust, respectively, with a mean estimated age of 6·9 years and 7·0 years. No differences were observed in the mean number of children or adults at the table by crust type (2·2 v. 2·3 children and 2·5 v. 2.6 adults) or the mean number of children’s pizzas ordered (1·5 v. 1·7 pizzas). Most pizzas had cheese (n 209) or pepperoni (n 95) as the only topping. Observers watched tables during approximately 63 % or 67 % of the meal time for refined- and whole-grain crust type, respectively. This was dependent upon the location of the table within the restaurant and the number of other tables being observed.

Table 1 Observation data by pizza crust type among child restaurant patrons in five Green Mill restaurant (a Midwest US chain) locations in the Minneapolis/St. Paul metropolitan area, Minnesota over an 8-month period, August 2012–March 2013

*P values are based on t tests (significance level: P<0·05).

†Where percentage does not sum to 100, data are missing.

P values are based on χ 2 tests (significance level: P<0·05).

§According to PROC GLM (significance level: P<0·05), adjusted for child gender, pizza type and whether the pizza was shared.

Child gender, type of pizza toppings and whether the pizza was shared were significantly different between the two groups (Table 1). More boys and fewer girls consumed the pizza made with whole-grain crust than the refined-grain crust. Pizzas with refined-grain crusts were more likely to be topped with pepperoni than pizzas with whole-grain crust. Children were less likely to share pizza made with whole-grain compared with the refined-grain crust. After adjusting for gender, whether the pizza was shared and differences in pizza toppings, the mean percentage waste did not differ significantly for children consuming the pizza made with refined-grain crust (55·4 %) v. the whole-grain crust (57·9 %). Children ate slightly less than half of the pizzas made with either type of crust. The adjusted model also showed that the type of topping affected the amount of waste, but only for sausage pizzas (P=0·02).

Discussion

Both liking and plate waste data showed that children consumed pizza made with refined-grain or whole-grain crust in equal amounts. These results support previous work in schools with pizza crust made with white whole-wheat flour( Reference Chan, Vickers and Marquart 7 ) and other whole-grain products made with white whole-wheat and barley flours( Reference Toma, Omary and Marquart 10 ). Similar findings were also observed by Chu et al. testing whole-grain tortillas and pancakes from the US Department of Agriculture Commodity Food Program in schools in two states( Reference Chu, Warren and Sceets 9 ). The foods other than pizza crust tested in these studies are also frequently served in restaurants to children and present opportunities for future research on acceptance.

Acceptance of the pizza crust made with whole-grain flour in restaurants in the current study and in schools in a previous study( Reference Chan, Vickers and Marquart 7 ) has implications for food-service personnel planning meals to meet school meal regulations for including whole-grain foods( 14 ). The new guidance for US schools requires that foods meeting the whole grain-rich criteria may contain a blend of whole-grain flour and enriched flour where at least 50 % is whole grain. Therefore the formulation of the whole-grain pizza crust tested in the current study conforms with the school meal regulations; however, the size was larger than recommended for use in schools. The pale colour and mild flavour of the white whole-wheat flour used in the current study may have contributed to the lack of difference in acceptance of the two types of pizza crust. Use of white whole-wheat flour represents a solution for food-service personnel concerned that the dark colour and bitter flavour of whole-grain foods will cause these foods to be rejected by students.

Introducing whole grains through a familiar and well-liked product was apparently successful in overcoming children’s barriers to consumption. However, the portion size of the children’s pizzas in the present study was extremely large (350–400 g) because the restaurant chain uses the same size dough ball for its children’s pizzas and individual adult pizzas. Although children consumed less than half of the pizza on average (44·5 %), the large serving size could have predisposed them to consume more of the pizza than they normally would have, as seen in a previous study( Reference Ramsay, Safaii and Croschere 15 ). Children in the current study would have consumed a full serving of whole grains and 3 g of dietary fibre by eating 44·5 % of the pizza with the whole-grain crust. The study should be repeated with a smaller serving size to verify that consumption of whole grains remains similar even if the serving size is reduced.

The strengths of the present study are in its novelty and potential application. Little information is available about restaurants as a potential site for increasing whole-grain intake among children. Further, the observations were conducted in a manner that preserved the integrity of the restaurant environment, ensuring authenticity in the eating behaviours observed. The tool developed in conjunction with the observation protocol was effective in allowing observers to quickly and easily record waste data. Limitations were related to conducting research in a restaurant environment. Observations were used to record plate waste v. actual weight of waste. However, observers were well-trained according to intra- and inter-observer reliability within a simulated setting. Observers were unable to observe children 100 % of the time and therefore may have occasionally missed or misreported pizza that was shared, dropped or discarded; however, observers were able to note that 36 % of refined-grain and 20 % of whole-grain pizzas were shared. Lastly, the study was conducted in the Midwestern USA within a chain of several sit-down pizza restaurants, which may limit its generalizability to other locations and other types of restaurant.

The outcomes of the present study could serve as the foundation for future work with large, national restaurant chains. Pizza is an ideal example of a food that benefits substantially from reformulation, but others exist. Hamburger buns, tortillas, pastas, rice and even breading on chicken tenders/nuggets could be redesigned in restaurants to include whole grains. These products are currently available for use in schools and could easily be adapted for use in restaurants. Future studies could focus on large organizations or small, independent businesses; each type of restaurant will present unique challenges and opportunities for intervention.

Acknowledgements

Acknowledgements: The authors would like to acknowledge Jon Schmig for his assistance in designing the observation tool used for data collection. Financial support: ConAgra Mills, Inc. assisted in the formulation of the pizza crust and provided the flour for the whole-grain crust, but had no role in the design, analysis or writing of this article. Conflict of interest: None. Authorship: All authors were involved in the conception and design, data collection and interpretation. A.T. and M.R. conducted the statistical analysis. A.T. drafted the manuscript. M.R. and L.M. provided critical revision of the manuscript. L.M. obtained funding and provided administrative and technical support. M.R. and L.M. provided supervision. Ethics of human subject participation: The study conducted in the school setting was approved by the University of Minnesota Institutional Review Board and the study conducted in restaurant settings was considered exempt from committee review by the same Institutional Review Board.

References

1. Ye, EQ, Chacko, SA, Chou, EL et al. (2012) Greater whole-grain intake is associated with lower risk of type 2 diabetes, cardiovascular disease, and weight gain. J Nutr 142, 13041313.CrossRefGoogle ScholarPubMed
2. US Department of Agriculture & US Department of Health and Human Services (2010) Dietary Guidelines for Americans, 2010. Washington, DC: US Government Printing Office.Google ScholarPubMed
3. Reicks, M, Jonnalagadda, S, Albertson, A et al. (2014) Total dietary fiber intakes in the US population are related to whole grain consumption: results from the National Health and Nutrition Examination Survey 2009 and 2010. Nutr Res 34, 226234.CrossRefGoogle ScholarPubMed
4. Rhodes, DG, Adler, ME, Clemens, JC et al. (2014) Consumption of Pizza: What We Eat in America, NHANES 2007–2010. Food Surveys Research Group Dietary Data Brief no. 11. Beltsville, MD: USDA/ARS.Google Scholar
5. Condon, EM, Crepinsek, MK & Fox, MK (2009) Types of foods offered to and consumed by children at lunch and breakfast. J Am Diet Assoc 109, 2 Suppl, S67–S78.CrossRefGoogle Scholar
6. The Whole Grains Council (2013) Whole White Wheat FAQ. http://wholegrainscouncil.org/whole-grains-101/whole-white-wheat-faq (accessed March 2013).Google Scholar
7. Chan, HW, Vickers, Z, Marquart, L et al. (2008) White whole-wheat flour can be partially substituted for refined-wheat flour in pizza crust in school meals without affecting consumption. J Child Nutr Manag 32, issue 1; available at http://docs.schoolnutrition.org/newsroom/jcnm/08spring/chan/index.asp Google Scholar
8. Lin, B & Morrison, R (2012) Food and Nutrient Intake Data: Taking a Look at the Nutritional Quality of Foods Eaten at Home and Away From Home. Amber Waves, 5 June. Washington, DC: USDA/ERS; available at http://www.ers.usda.gov/amber-waves/2012-june/data-feature-food-and-nutrient-intake-data.aspx# Google Scholar
9. Chu, YL, Warren, CA, Sceets, CE et al. (2011) Acceptance of two US Department of Agriculture commodity whole-grain products: a school-based study in Texas and Minnesota. J Am Diet Assoc 111, 13801384.CrossRefGoogle ScholarPubMed
10. Toma, A, Omary, MB, Marquart, LF et al. (2009) Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods. J Food Sci 74, H139H146.CrossRefGoogle ScholarPubMed
11. ESHA Research (2012) Genesis R&D Product Development and Labeling Software, Version 9.8.0.0. http://www.esha.com/product/genesis-nutrition-label-software (accessed February 2014).Google Scholar
12. Kroll, B (1990) Evaluating rating scales for sensory testing with children. Food Technol 44, 7886.Google Scholar
13. Popper, R & Kroll, JJ (2007) Consumer testing of food products using children. In Consumer-Led Food Product Development, pp. 383406 [H MacFie, editor]. Cambridge: Woodhead Publishing Limited.CrossRefGoogle Scholar
14. Food and Nutrition Service, US Department of Agriculture (2012) Nutrition standards in the national school lunch and school breakfast programs. Final rule. Fed Reg 77, 40884167.Google ScholarPubMed
15. Ramsay, S, Safaii, S, Croschere, T et al. (2013) Kindergarteners’ entree intake increases when served a larger entree potion in school lunch: a quasi-experiment. J Sch Health 83, 239242.CrossRefGoogle Scholar
Figure 0

Fig. 1 The observation form developed to record percentage waste in restaurant settings

Figure 1

Table 1 Observation data by pizza crust type among child restaurant patrons in five Green Mill restaurant (a Midwest US chain) locations in the Minneapolis/St. Paul metropolitan area, Minnesota over an 8-month period, August 2012–March 2013

You have Access
9
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Reformulation of pizza crust in restaurants may increase whole-grain intake among children
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Reformulation of pizza crust in restaurants may increase whole-grain intake among children
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Reformulation of pizza crust in restaurants may increase whole-grain intake among children
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *