This paper has two main aims: (1) to describe the design, implementation, and testing of a protocol to assess longitudinal changes in F&V plate waste conducted as part of a quasi-experimental study, (2) to provide baseline descriptive data on school demographics and study participants. This paper describes the protocol development and implementation, and presents baseline data of a longitudinal fruit and vegetable (F&V) plate waste study. The protocol was developed to determine the preliminary impact of Brighter Bites, a 16-week school-based nutrition intervention, on F&V wasted and nutrients wasted from school lunches. We measured plate waste using a quasi-experimental design (n = 2 intervention schools receiving Brighter Bites, n=1 comparison school; n = 115 4th and 5th grade children). We measured plate waste for five days at each of four time points over the 2017-2018 academic year (baseline prior to intervention, three additional time points). Data collectors measured lunch F&V waste using digital scales and recorded weights on a data collection app. This study was conducted in three central Texas public elementary schools serving predominantly low-income families (>89% of children on free/reduced lunch program). On average, at baseline, 59.1% of all F&V were wasted and children tried <1 F&V at meals. Foods most wasted were legumes and foods least wasted were par-fried baked potatoes. Final retention rate across the four time points was 75.70%. Measurement inter-rater reliability was 100% (r = 0.99). Our study presents a protocol for detailed, individual-level, longitudinal plate waste assessment in elementary schools.
Keywords: dietary intervention; plate waste; school lunch.