Strategies to reduce plate waste in primary schools – experimental evaluation

Abstract

Objective: To determine and compare the effect of two interventions in reducing the plate waste of school lunches. Design: A between-group analysis was conducted among children from three primary schools: (i) a group receiving intervention A, designed for children and focusing on nutrition education and food waste; (ii) a group receiving intervention B, intended for teachers and focusing on the causes and consequences of food waste; and (iii) a control group with no intervention. For each child, physical weighing of individual meals and leftovers was performed on three non-consecutive weeks at baseline (T0), 1 week (T1, short term) and 3 months (T2, medium term) following the intervention. Plate waste was recorded for a total of 1742 lunches during 14 d over eight different menus. Setting: Portuguese public primary schools in the city of Porto. Subjects: All fourth-grade children (n 212) attending the three preselected schools. Results: After intervention A focusing on nutrition education designed for children, a decrease in soup waste was observed compared with the control group. The effect was greater at T1 (−11·9 (SE 2·8) %; P < 0·001) than at T2 (−5·8 (SE 4·4) %; P = 0·103). The plate waste of identical main dishes decreased strongly at T1 (−33·9 (SE 4·8) %; P < 0·001). However, this effect was not found at T2 (−13·7 (SE 3·2) %; P < 0·001). After intervention B involving teachers, plate waste decreased at T2 (−5·5 (SE 1·9) % for soup; −5·4 (SE 2·4) % for identical main dishes). Conclusions: Nutrition education designed for children was more effective in the short than the medium term. Thus, this kind of intervention was not effective in reducing food waste in the medium term. In contrast, an intervention focusing on teachers revealed better results in the medium term than in the short term.

Food Waste and Nutrition Quality in the Context of Public Health: A Scoping Review

“…A range of publication types were included in this review, including 10 cross-sectional studies [ 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ], one review [ 68 ], two systematic reviews [ 69 , 70 ], two case studies [ 71 , 72 ], seven intervention studies (three non-randomized controlled trials [ 73 , 74 , 75 ], one randomized controlled trial [ 76 ], three pre-post-design studies [ 77 , 78 , 79 ]), one observational study [ 80 ], one comparative analysis [ 81 ], one critical evaluation [ 82 ], one time series [ 83 ], one multi-method study [ 84 ], and six food-based dietary guidelines [ 85 , 86 , 87 , 88 , 89 , 90 ]. Four main concepts were mapped from the resulting data ( Figure 3 ), and the publications were grouped into these concepts as appropriate.…”

“…Six interventions were school-based interventions that aimed to reduce food waste while improving nutrition knowledge, diet quality, and/or nutritional intake [ 73 , 74 , 75 , 76 , 77 , 78 ]. Three of four education intervention studies reported decreases in food waste and improvements in nutritional intake in the intervention groups in comparison to the control groups, including maintaining or increasing fruit and vegetable intake or increasing the consumption of nutritionally balanced school meals [ 73 , 74 , 75 ]. One study did not find any improvement in dietary intake or plate waste [ 76 ].…”

Healthy Planet, Healthy Youth: A Food Systems Education and Promotion Intervention to Improve Adolescent Diet Quality and Reduce Food Waste

“…Additionally, wasted food squanders the natural resources used to derive food and is a major contributor to climate change [11,12]. Traditional nutrition education interventions that target students’ selection, consumption, and waste of fruits and vegetables during school meals are rarely effective past the short-term [13,14], suggesting that a novel approach is warranted.…”

Promoting Food Waste Reduction at Primary Schools. A Case Study

“…Then the average was calculated for each diner. The weighing method is considered the most precise method for quantifying FW compared to others, such as visual estimations, estimations with digital photographs or self-assessments using questionnaires [24,[48][49][50][51]. The protocol for measuring FW on plates was defined by adapting the protocols described in previous works [47, 48,52], and consisted in weighing three random portions of each menu component and taking their average as the weight of served portions.…”