Nutritional Contribution and Quality of Lunches Consumed During School Lunch Periods in Canadian Elementary Schools: A Plate Waste Analysis

Background/Objectives: Foods and beverages consumed during school lunch periods contribute substantially to children’s dietary intake; however, Canadian evidence of their nutritional contribution and quality remains limited. This study assessed nutrient content, nutrient density, and contributions to dietary recommendations among Saskatchewan elementary students. Methods: A descriptive quantitative study was conducted among 379 students aged 5–13. Dietary intake during school lunch periods was assessed using a photography-assisted plate waste method. Nutrient content was estimated using standard nutrient databases, nutrient density was evaluated using the Nutrient-Rich Food (NRF) 9.3 Index, and contributions to dietary recommendations were examined. Results: Median lunch energy was 411.4 kcal (IQR: 296.7), and the mean NRF 9.3 score was 292.6 (SD: 130.7). Compared with home-packed and mixed lunches, school-provided lunches contained less energy, carbohydrate, fat, and sugar, while protein was similar across lunch types. Overall, lunches contributed <25% of daily requirements for key nutrients, including fibre, vitamin D, calcium, and potassium. Older students had lower proportional nutrient contributions relative to their higher nutritional requirements. Nutrient density differed by lunch provenance, but not by age or reported gender, with school-provided lunches achieving the highest NRF 9.3 scores. Conclusions: Lunches contributed modestly to daily nutrient requirements, particularly among older students. In this sample, school-provided lunches were associated with higher nutrient density than home-packed lunches, although their absolute contributions to several nutrients remained limited. These findings provide baseline evidence on lunches consumed during school lunch periods among Saskatchewan elementary students and may inform future evaluations of school food systems and policies.