"Plate Tectonics": Do farm-to-school programs shift students diets?

by Jeri Ohmart and Gail Feenstra, UC SAREP

Over the past five years, farm-to-school salad bar programs have begun to proliferate across the country. As programs appear, we often hear the claim that children will reject fresh produce. Yet initial reports suggest that, when presented with fresh fruits and vegetables in a salad bar format, children readily choose them. But what exactly do kids choose? What do their preferences look like, and how do their salad bar choices differ from the USDA hot lunch that is a school’s normal fare? What conclusions can we draw about their diets from these new programs? These were the questions informing a recent study conducted by Gail Feenstra, UC SAREP food systems analyst; Jeri Ohmart, UC SAREP food systems program assistant; and Melissa Salazar, graduate student in the UC Davis School of Education.

Since 2001, Davis Joint Unified School District (DJUSD) has been implementing a farm-to-school salad bar program. An integrated program that includes gardening, nutrition education, on-site recycling, and farm tours, it features a cafeteria salad bar stocked with farm-fresh, seasonal produce from local farmers. During this time, we have seen total district produce purchases more than triple, from $13,000 to more than $42,000, and produce purchases dedicated solely to the salad bar increase more than eight times, from $4,000 to almost $35,000. Children’s access to produce has definitely increased.

By the fourth year of the program DJUSD Food Services Director Rafaelita Curva was faced with some questions about what the children were actually taking from the salad bar. Early in 2004, she requested that Feenstra and Ohmart take pictures of student lunches. It became clear that these photographs held a wealth of data about the amounts and kinds of food students were choosing.

We approached the principals at four Davis elementary school and two schools in the nearby rural community of Winters and received permission to take photos of children’s school lunches. Eight hundred and fifty photos later, we collated information and assessed the contents of students’ lunch plates. Using USDA minimum serving requirements as a baseline¹, and creating a visual model of serving sizes, we calculated for each plate the amount of protein (meat or meat alternative), amount of fruit and vegetables, number of choices of fruit and vegetables (variety), and number of bread servings. Servings of croutons and ranch dressing were also evaluated.

At the time we conducted this study, DJUSD was transitioning from a lunch consisting of both a salad bar and a hot lunch entrée combination to a model that offered a salad bar only on two days per week and a hot lunch only on three day per week. Since the transition period took place gradually over a period of six weeks, we were able to photograph all three types of lunch: combination lunch, salad bar only, and hot lunch only. In this way, we could draw comparisons among types of lunches to test our hypothesis that children are taking more fruits and vegetables with a salad bar model.

The results were interesting and confirmed our hypotheses. First, we looked at overall averages for all types of lunches. In Davis, fruit/vegetable servings per plate were over the USDA minimum requirement—.83 of a cup compared to the required .75 of a cup (111% of the minimum). However, the number of choices (variety) and protein servings was below minimum, while the number of bread servings was above minimum.

Next, we looked within categories, and here we see a different profile (see Figure 1). The “salad bar only” lunch showed a significantly higher amount of fruit and vegetable servings compared to the other two categories (120% over the minimum requirement). The “salad bar only” model also showed the highest percentage in the variety, while it rated lower than minimum in protein and bread servings.

The “hot lunch only” was below the minimum in each category except for bread servings, where it was above the minimum, equaling the combination lunch. The hot lunch scored the lowest of the three in variety, and at 77% of the minimum requirement of fruits and vegetables, this lunch appeared to be the least healthful.

The combination lunch rated relatively well, with 100% in both protein and fruit/vegetable servings, but low on variety and high on bread servings.

Winters is a small community near Davis and although both are surrounded by farmland, Winters has a much more rural character. Over half the area’s population is Hispanic, most of the families are involved in agriculture, and the elementary schools record a higher percentage of students eligible for free and reduced lunch (over 60% compared to Davis’ 23%). In Winters, salad bar days are similar to a “combination lunch” in Davis. They are presented as “theme” days, offering in addition to the salad bar, a hot entrée corresponding to a cultural theme such as Italian (spaghetti day) or Mexican (taco or nacho day).

Results of the Winters study showed a much closer adherence to the USDA requirements. Protein servings were slightly over the minimum requirement (107%), fruit and vegetable servings were 116%, number of choices was 103% and number of bread servings were about 78%. Looking at the photographs raises interesting questions. In addition to the fresh lettuce, carrots and tomatoes in the salad bar, children were also able to choose olives, chilies, salsa and tomato sauce, which are counted in the fruit/vegetable category.

One of the most interesting results of using this methodology was to see the extensive variety on the plates on “salad bar only” days. The contrast to “hot lunch only” days was striking (see photos). There is clearly less variety in fruit and vegetable selections on “hot lunch only” days. The study provided a fascinating insight into the ways children select their food, arrange it on the plate, and their reasons for choosing what they did.

Conclusions drawn from the study include:

• When many kinds of fruits and vegetables are offered, kids take them. This is most true when options are fresh.


• Salad bars raise fruit and vegetable consumption. Kids take more than the USDA minimum, and the variety is good.


• Choice and variety are important dimensions of meals. The most common reason kids cited for preferring the salad bar was the element of choice.


• In addition to looking at minimum requirements in quantity, it is important to look at the extent to which food has been processed. Specifically, it is important to consider fat content, sugars, processed vs. fresh foods, food dyes and additives. Other considerations include food packaging and delivery methods.

Children know what tastes good to them. They will choose fruits and vegetables when they are fresh and presented in an appealing way. Even children who eat “fast food” are quick to tell you when their lunch servings are not fresh or have a “plastic” taste. Being able to see the food and choose those items they want is important to children. Offering a variety of choices among fresh, minimally processed foods will pay off in long-term health. For more details on the study, contact Jeri Ohmart at jlohmart@ucdavis.edu or Gail Feenstra at gwfeenstra@ucdavis.edu.

¹ USDA minimum requirements are 2 ounces of meat/meat alternative; 3/4ths cup of fruit and/or vegetable (plus an additional serving of ½ cup during the course of the week); two types of fruit and/or vegetable; two servings of bread. We counted 20 croutons as one bread serving (per Food Services). We also counted ranch dressing in number of tablespoons, although there is no guideline for ranch dressing.