Filtered Plate Waste Measurement Data from Latvian Schools (Rezekne, Grades 1–7), December 2023.

This dataset contains filtered plate waste measurement data collected from four secondary schools in Rezekne, Latvia, as part of a field experiment evaluating interventions to reduce plate waste in school canteens. The data were collected using the direct weighing method. The study was conducted in schools operating under a partly pre-served catering model, which is typical for Latvian public schools. In this model, the main dish is pre-served on individual plates, and students do not freely choose portion sizes. The dataset covers students in Grades 1–7 (approximately aged 7–13) who received free school lunches funded by municipal and state resources. The dataset includes only individual plate waste generated by students. Food waste originating from common serving plates, shared bowls, pots, or other communal containers (e.g., salad, soup, and bread) was excluded in order to ensure consistency and to focus on individual consumption behavior when assessing the impact of interventions. A filtering procedure was applied to extra-served meals resulting from student absences. Extra portions that were served but not consumed at all were excluded from the dataset. If an extra served meal was partially consumed by classmates, it was included in both the served food amount and the corresponding plate waste amount, in accordance with the study’s methodological approach. All measurements were conducted under controlled conditions with a unified menu design to minimize menu-related variability. Data were anonymized at the school level, and no personal data of pupils were collected. In addition to aggregated school-level data, the dataset includes plate waste measurements aggregated by student groups. These groups distinguish between Grades 1–4 (approximately aged 7–10) and Grades 5–7 (approximately aged 11–13), corresponding to primary and lower secondary school levels. This structure enables comparative analysis of plate waste across different age groups while preserving student anonymity. Full details on the study design, catering model, measurement protocol, and data processing are provided in the associated peer-reviewed publication https://doi.org/10.3390/foods14010126 This research was funded by the Latvian Council of Science project No.lzp-2022/1-0492.