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The Veggie Project

Research Papers

Dylan Bates and Joseph Price (2015). Impact of fruit smoothies on adolescent fruit consumption at school. Health Education and Behavior Journal.

Abstract: We examine the impact of serving fruit smoothies during school breakfast on fruit consumption among middle school and high school students. We draw on observational plate-waste data over a 10-week period during which fruit smoothies were introduced for breakfast at two Utah schools. Our total sample includes 2,760 student-day observations. We find that the fraction of students eating a full serving of whole fruit increased from 4.3% to 45.1%. As such, school districts should consider offering fruit smoothies as part of a set of interventions designed to increase fruit consumption at school.

David Just, Joseph Price (2014). Lunch, Recess and Nutrition​. Preventative Medicine. News Coverage: http://news.byu.edu/archive15-jan-schoollunch.aspx​

Abstract: In this study, we evaluate if moving recess before lunch has an effect on the amount of fruits and vegetables elementary school students eat as part of their school-provided lunch. Participants were 1st–6th grade students from three schools that switched recess from after to before lunch and four similar schools that continued to hold recess after lunch. We collected data for an average of 14 days at each school (4 days during spring 2011, May 3 through June 1, 2011 and 9 days during fall 2011, September 19 through November 11, 2011). All of the schools were in Orem, UT. Data was collected for all students receiving a school lunch and was based on observational plate waste data. We find that moving recess before lunch increased consumption of fruits and vegetables by 0.16 servings per child (a 54% increase) and increased the fraction of children eating at least one serving of fruits or vegetables by 10 percentage points (a 45% increase). In contrast, the schools in our control group actually experienced a small reduction in fruit and vegetable consumption during the same time period. Our results show the benefits of holding recess before lunch and suggest that if more schools implement this policy, there would be significant increases in fruit and vegetable consumption among students who eat school lunch as part of the National School Lunch Program.

David Just, Joseph Price (2013). Using Incentives to Encourage Healthy Eating in Children. Journal of Human Resources. News Coverage: http://news.byu.edu/archive13-dec-veggies.aspx

Abstract: There is growing interest in the situations in which incentives have a significant effect on positive behaviors, particularly in children. Using a randomized field experiment, we find that incentives increase the fraction of children eating a serving of fruits or vegetables during lunch by 80% and reduces the amount of waste by 33%. At schools with a larger fraction of low-income children, the increase in the fraction of children who eat a serving of fruits or vegetables is even larger, indicating that incentives successfully target the children who are likely to benefit the most from the increased consumption.

David Just, Joseph Price (2013). Default options, incentives and food choices. Public Health Nutrition.

Abstract: The objective was to examine whether requiring children to place fruits and vegetables on their lunch trays increases consumption of these items. The design was an observational study that exploited naturally occurring variation between two school districts and a pre–post observational study at schools that changed their lunch policy mid-year. The settings was fifteen elementary schools from two school districts, one requiring students to place a fruit or vegetable on their tray and one that does not. In addition, three schools that implemented a default option part way through the school year. Students at eighteen elementary schools (41 374 child-day observations) across the two experiments were involved. Requiring that fruits and vegetables be placed on each child's tray increased the fraction of children who ate a serving of fruits or vegetables by 8 percentage points (P < 0·01) but led to an extra 0·7 servings being thrown away per lunch served (P < 0·01). The default option approach cost $US 1·72 to get one additional child to eat one serving of fruits and vegetables for 1 d. However, when default options were combined with a small rewards programme the efficacy of both interventions increased. A default option, as a stand-alone programme, had only a limited impact on fruit and vegetable consumption but was much less cost-effective than other approaches. Schools requiring children to take fruits and vegetables with their lunch might consider adopting additional interventions to ensure that the additional items served do not end up being thrown away.

​David Just, Jesse Lund, and Joseph Price (2012). The role of variety in increasing the consumption of fruits and vegetables among children​. ​Agricultural and Resource Economics Review.

Abstract: We use observational data from 22 elementary schools and over 48,000 child-day observations to examine the relationship between the number of fruit and vegetable items and the consumption patterns of children during school lunch. We find that each additional fruit or vegetable item that is offered increases the fraction of children who eat at least one serving of fruits and vegetables by 12%. We also use our observational data to provide practical information about which items are most likely to be eaten by children during lunch and compare this to the cost and nutritional quality of these items.

George Loewenstein, ​Joseph Price, and Kevin Volpp (2014). Habit formation in children: Evidence from incentives for healthy eating. ​Working Paper​.

Abstract: We present findings from a field experiment conducted at 40 elementary schools involving 8,000 children and 400,000 child-day observations, which tested whether providing short-run incentives can create habit formation in children. Over a three or five week period, students received an incentive for eating a serving of fruits or vegetables during lunch. Relative to an average baseline rate of 39%, providing small incentives doubled the fraction of children eating at least one serving of fruits or vegetables. Two months after the end of the intervention, the consumption rate at schools remained 21% above baseline for the three-week treatment and 44% above baseline for the five week treatment, a significant difference. These findings indicate that short-run incentives can produce changes in behavior that persist after incentives are removed and support the natural intuition that longer interventions produce more persistent habits.