Grapes In School Lunch

Research and Data

Originally printed in the June 2018 issue of Produce Business.

Nourishing the minds and bodies of the nation’s school-age children and teaching them how to eat healthfully on their own is the very important role of the Child Nutrition Programs run by the USDA Food and Nutrition Service. To achieve these goals, balanced meals must be presented in a way that reinforces the selection of healthy foods, and of course, the meals must actually be consumed. 

Since the passage of the Healthy, Hunger-Free Kids Act in 2010, schools have been working through the challenges of offering healthier options that are accepted by their students. One bright spot has been the increase in fresh fruits and vegetables offered on school menus, and overall, according to the USDA, children are eating more fruits and vegetables because of the updated standards. School districts have seen increased participation in the meal plans when schools promote their fresh offerings to their students (Center for Ecoliteracy.org). Yet overall plate waste in school cafeterias remains an ongoing concern. 

It has been suggested that certain fruits and vegetables serve as “gateway” foods to promote healthier food consumption overall. To test this intriguing hypothesis, researchers at Texas A&M University designed and conducted a study to explore this concept. Fresh grapes were selected as the test food based on the following assumptions: 1) grapes are known to be universally well-liked by children of all ages; 2) fresh domestic grapes from California are widely available to school foodservice operators across the United States; and 3) grapes are convenient to serve. One half cup of fresh grapes meets the school lunch fruit serving requirement.

An observational study on grapes and health published in the Journal of Food Science1 showed that, among adults and children, consumption of grapes and grape products is associated with healthier dietary patterns and improved nutrient intakes. The study analyzed the diets of more than 21,800 children and adults using data from the 2003-2008 National Health and Nutrition Examination Survey (NHANES.)

Not only were healthier food options increasingly consumed, but in addition, the consumption of less healthy food decreased. Adult grape consumers had increased intakes of vegetables, whole grains, nuts and seeds but lower intakes of added sugars, total fat, saturated fat and cholesterol compared to non-consumers. Could a similar benefit be realized in the school foodservice setting by adding grapes to school lunches? A school lunch-focused, plate waste study was designed to explore this hypothesis.

The study2 was conducted in two elementary schools and two middle schools from one school district in Texas. The study participants were students from kindergarten through the eighth grade who participated in the National School Lunch Program. Grapes were made available on “grape days” as an offered fruit choice. “Non-grape days” were defined as those days where grapes were not offered. Plate waste was defined as the quantity of edible portions of food served that students discarded. A total of 72 observations were made across the grades and schools.

The findings from this study showed that when the food environment included grapes, consumption of healthier menu items increased, while consumption of less healthy menu items decreased:

  • When offered as a fruit choice, grapes were minimally wasted.
  • On grape days, lost dollars attributed to vegetable plate waste were significantly less than on non-grape days.
  • Intakes of effective calories, fat, sodium, protein and fiber per serving of entrees, vegetables and fruits on grape days were higher than on non-grape days.
  • On grape days, the children consumed more of the school lunch, which is an overall goal of the school lunch program.

The takeaway: offering grapes in school lunches is an effective strategy that goes beyond grapes’ status as a favorite fruit to grapes having a beneficial impact on the degree to which children make healthy meal choices and on their consumption of the school lunch overall. 

The many players in school foodservice – from the district managers to the on-site operators and their critically important frontline servers – are working every day to deliver tasty, nourishing meals that get eaten. The impact is huge: through the National School Lunch Program alone, nearly 100,000 schools serve more than 30 million children each day. The USDA provides an array of tools and training designed to support these efforts. However, meeting the taste expectations of millions of children from all walks of life is no small task, and many prepared products continue to be re-engineered and fine-tuned to meet the new standards and kid palates.

Another option?

Foodservice directors can seek new opportunities to leverage the potential of fresh produce, as demonstrated with fresh grapes in the Texas A&M plate waste study, to further their success in providing meals that get eaten.

1McGill CR‭, ‬Keast DR‭, ‬Painter JE‭, ‬Romano CS‭, ‬Wightman‭, ‬JD‭. ‬2013‭. ‬Improved diet quality and increased nutrient intakes associated‭ ‬with grape product consumption by U.S‭. ‬children and adults‭: ‬national health and nutrition examination survey 2003‭ ‬to 2008‭. ‬J Food Sci 78‭(‬6‭) ‬A1-A4‭. ‬
2Murano PS‭, ‬Capps O‭. ‬2018‭. ‬Grapes in School Meals‭: ‬Impact of Plate Waste on Costs and Consumption‭. ‬J Nutrition Health Food Sci 6‭(‬1‭):‬1-9‭.‬


Peter S‭. ‬Murano‭, ‬Ph.D‭., ‬is a researcher in the Department of Nutrition and Food Science at Texas A&M University‭. ‬In addition to‭ ‬publishing in the fields of nutrition and food science‭, ‬he has authored two textbooks‭ (‬Exploring Food Science and Technology ‬for Kendall Hunt‭, ‬and‭ ‬ Obesity‭: ‬A Social and Scientific Challenge, for Sentia Publishing‭), ‬and is former Deputy Administrator with the USDA Food and Nutrition Service‭.‬


Comments & Analysis

Promising Start To Bigger Study

By Jim Prevor, Editor-in-Chief, Produce Business

As is so often the case, research results create questions that necessitate even more research. Such is certainly the case with the interesting studies that Dr. Murano shares with us here. Although this particular study’s object was grapes, it is not 100 percent clear that the results are unique to grapes.

Jim Prevor - Editor in ChiefIn explaining the menu, the researchers write this:

At elementary schools, a maximum of three entrees were offered, with the menu cycling through an eight-week rotation. Corresponding vegetables and fresh condiments were offered with each of the entrees as well. In addition to grapes, typically, four to five additional prepared (canned) fruits were offered, such as mixed fruit cocktail, peaches, applesauce, pineapples, and mandarin oranges. Whole fruit that was available included whole bananas, oranges, and red and green apples, in addition to grapes. Both red and green grapes were offered, based upon availability and cost. Typically 14 grapes were offered per tray; red and green grapes were not mixed. Dried fruit — specifically raisins and Craisins — were offered as a fruit choice.

So, every day, the students were offered two things: some fresh whole fruits and some canned fruits. Then there were some special “grape days” during which the students were also offered fresh grapes. The claim is that various positive things happened — less food waste, higher consumption of produce, higher utilization of food, etc. — when the fresh grapes were added to the menu.

Assuming all these good things are true and would replicate if the study were repeated — it was a small study in only two schools in one geographic area and was restricted only to volunteers and only to students on the National School Lunch Program, so whether it would stand up to replication on a national basis to all children is very much a question for further research — >there is another question that gets to the core of what is actually being studied: Are the results telling us something about grapes in particular or about a preference for fresh over canned? The researchers go on to say that the fact that the other daily items are processed is not a problem:

Since canned fruits and vegetables are typically packed within hours of harvest, their peak flavor and nutritional value are preserved – making comparisons relevant and equivalent.

We don’t have to quibble on the taste or nutritional value of these canned fruits. We can simply acknowledge that human preferences are not determined solely by taste and nutritional value — although we would say the taste of canned mandarin orange sections is different than that of say, fresh Cuties, Halos or other easy-peelers. In any case, value perception can be affected by many things, and Fresh, itself, may culturally have a higher value perception.

The gold standard in research is double-blind, where neither researchers nor the research subjects know what is being studied.

So, the addition of a fresh snack item, if consumed to great effect, might simply be showing a preference for fresh snack items. It might have nothing particularly to do with grapes. If there were other control schools, and some had fresh blueberries, others with fresh strawberries, others with fresh cherries, others with cubed watermelon, etc., etc., perhaps the results would have been identical.

This issue of fresh vs. canned is especially important because, due to research limitations, the researchers excluded the existing fresh product from the study:

Exclusions: Whole fruit (bananas, apples, oranges) were excluded due to lack of space, time and manpower to separate skin, seeds, and core.

Fair enough, but isn’t it plausible that students who have now eaten one fresh fruit — grapes — might eat fewer of the fresh fruits they eat on other days? So, the data shown here – calories consumed etc. — might be very different if the pre-study offer of fresh fruits was included in the study.

Another issue requiring further research is the impact of knowing one’s behavior is being studied. The methodology was not unobtrusive:

As the students entered the cafeteria and lined up at the lunch lines, two research assistants were positioned at the register to affix Post-it notes (color-coded) providing information identifying which foods were on each child’s tray. Upon completion of the meals, the research assistants at the preset tables collected trays.

Since the only variable was fresh grapes, and these researchers were quite involved in putting Post-it notes on everyone’s trays and collecting the trays, it seems very plausible that the students, the cafeteria workers, teachers, etc., knew some study was being done and it was related to grapes.

It is well known, even by children, that fresh fruits and vegetables are healthy. The fact that they knew they were being studied could have led everyone involved to want the “Right” outcome — higher consumption.

The gold standard in research is double-blind, where neither researchers nor the research subjects know what is being studied. It is better if they don’t know a study is being done at all!

Of course, the other issue is that the study was very short-term. Perhaps grapes suddenly appearing are a treat and result in behavioral change. But, perhaps, the addition of grapes to the regular menu might see this effect dissipate as the students acclimate to the availability of grapes.

The researchers have identified an incredibly powerful effect. Now we need more research to see if it is grapes, or something else, that is causing the effect, and whether the research applies to a more diverse group of students and will it be sustained over time.

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